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Ok, I've got my first significant task ahead of me: brake adjustment. The brakes are brand new – installed by someone who knows what they are doing. However they don't have even one hour on them and they are behaving intermittent. I can stand on the pedal and sometimes get nothing. Stab it a few times and suddenly the brake will grab. The theory is the new bands were stiff and have since relaxed a bit.
So here goes…first key question: Are these the brake adjusters? (yes I know there are several other places to adjust but the manual says these are step one)
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Correct. Those are the long bolts with the lock nuts. On page 31 of the manual it isn't specific about the sequence of taking up on these bolts but I believe it is important to tighten the upper ones (back of tractor) first, pushing the brake band down and around towards the front thereby minimizing the slack at the top rear. Tightening the bottom bolts next continues to force the band towards the front, permitting the best adjustment.
The only things I can think of that would give the symptoms you describe is:
a) A band that is bent warped, or out of round.
b) Lining that is loose on the band or has broken and tried to overlap itself.
c) Oil or grease on the lining.
When the bands are installed care must be taken to ensure they are as true round and fit to the hub as possible, otherwise you will get inaccurate adjustments and possibly a “spongy” pedal. There is nothing to “seat in”.
Member “Mailman55” has a rather unothodox way of adjusting the brakes and clutches , maybe he will chime in.
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Griz, If you are moving the crawler and pull back on both handles at the same time does machine stop moving…always? I would try it several times.
Here's my thought. When I worked for Deere we would sometimes hear about brakes being intermittent on crawlers. Sometimes the cause was clutches not releasing rather than brakes not working. This is a shot in the dark since it is unknown when the condition occurs.
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I have worked on many crawlers and owned a few. As for the Yuchai I ran one for about an hour as I was thinking about selling them. However it was not like yours. But no matter if you can release the clutches without applying the brakes then each time you do that the machine should come to a stop. Some of the Deere machines had both the clutches and brakes combined in the levers. If you pulled them back part way the clutches released. Pulled the rest of the way and the brake will apply. What this design did was remove the foot brake from the operation of turning. All the operator had to do was pull the lever back to turn right or left.
Larry
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The first 1/2″ to 3/4″ of pedal travel will be just for taking up the slack in the linkage.
(On larger dozers there are separate handles and levers for the steering clutches and brakes. There just isn't room on the Yuchai's so the dual functions are combined into a single sequential system using only pedals.)
The next 1″ to 2″ of travel will be for the release of the steering clutch, the remainder of travel is to keep the steering clutch released PLUS application of the brake. Total pedal travel is about 5-1/2″.
The top cover plate also contains the upper pivot for the clutch release fork shaft (upper separating fork shaft), so in answer to your question – yes, and no. You can remove the plate to see but you can't move anything, and you can't see much.
“Push both clutches in but not the brakes and the tractor should stop every time.”
In theory yes, but not necessarily. Depends on condition of the clutches. They could drag a little, and the tractor isn't that heavy so it could roll on easily.
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Well I had a fun lunch break today. Drove the dozer up and down my street.
The verdict is when I push both pedals part way the dozer stops every time. The street is pretty level so no coasting really. Ok, so that tells me the clutches are doing their thing.
Next I played with stomping on the brakes. All the way until the pedal stops every time. First thing I noted was the right pedal hits the hydraulic lines coming up from the floor. MUST fix that! If I push the pedal to the left a bit as I push down I can slide by for now.
Paying close attention to things I've come to the conclusion the brakes aren't so much intermittent as just plain weak. If I am really moving, high gear, they barely do anything at all. The other track sort of moves everything forward. If I slow down I get a bit more braking action but there the left is doing much more than the right. I even got a bit of a squeal from the right at one point.
So unless something is truly broken with these brand new brake bands, I'm going on the assumption they simply need to be tightened up. I'd like to avoid making changes to the clutch adjustment when I do this since that seems to be just right. About an inch of free play then good clutch feel. So here is my plan:
1) adjust the adjustment bolts per the manual. Top one first per Bob's suggestion. Screw in until they stop; back off a full turn; tighten nut. Rinse repeat four times total. (once per bolt)
2) adjust the control rod at the brake-band end to get the right free play or throw or whatever. Not super clear on this adjustment. Basically I'm trying to avoid the brakes coming on before the clutch is released AND trying to get it to bottom out before I have less than 30mm of clearance between pedal and bulkhead. I envision something like this:
while trying to avoid this:
p.s. I miss my little hammering smiley that was one of my favorites. Tried to get clever but it doesn't look the same on the forum as when I'm editing.
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Don't expect to get a lot of response from the brakes at high speeds, you're dealing with a lot of inertia there relative to the size of the bands.
Squealing while turning indicates the clutch plates are contacting each other, probably because the brake is coming on a little early, or the plates aren't separating fully. This may go away in a few more hours of operation. If not, you will have to readjust the clutch and brake sequence.
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Grizz wrote:
“First thing I noted was the right pedal hits the hydraulic lines coming up from the floor. MUST fix that! If I push the pedal to the left a bit as I push down I can slide by for now.”
In the following pic you can see what member Bluenoser did, he re-routed hoses above the deckplates to the right of the pedal (although with the pendulum pedals I don't know if there would be interference). The orange “X” marks the section that I cut out on my plate to allow better hose routing.
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Now I understand. I see that it's the lift cylinder hoses and not the pump suction and discharge hoses that are the issue. What I would do, if possible, is break out the rosebud and put a slight dog leg toward the inside in the pedal arms and/or just put a heavy sheet metal wear guard around the hoses.
Your deckplates appear flush across (very nice), mine and others are recessed about 1-1/2″, a real dirt catcher. Either way, they have to come out for steering and brake adjustments.
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Ok…finally found some time to get to this. Bunch of questions and comments.
First. There is no earthly way to get that deck plate off of there without removing the seat. Second. The seat is trapped by all those hoses. However after quite a bit of cussing it saw it my way. Needless to say if I ever do this adjustment again, I'm finding a way to do it from underneath.
I decided to look at how the mechanism is working now for comparison purposes. My first observation was that as I pushed the pedal both the clutch arm and the brake arm moved at the same time.
Is that right? Doesn't seem right to me.I'm stuck on step one however. I carefully marked where the “adjustment bolts” are now and then loosened the retaining nut and screwed them in. The results were odd.
Top bolt: I was expecting it to come to a sudden stop. It didn't. It just gradually got harder to turn. I figured a herculean effort is wrong and I should be feeling for “snug”. I stopped where I was happy. It took at least four full turns from where it was to where it stopped. Hmmm ok well maybe the mechanic had a different opinion of “snug”. No worries…press on. I backed it out one full turn just like the good book says and locked it down. On to the one at the bottom.
Bottom bolt: Again I marked where it was to start and started to turn it in. I turned…and turned…and turned…lost count…turned more…hmmm not getting any harder….turn..turn turn…. bottoms out on the locking nut before it got “snug”.
Ok, so what do I do now?
I'm completely up to my neck in “lost”. Any help you guys can give will be appreciated.
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Thanks for the fast reply bob! Should I be turning these bolts with my bare hands or wrenches? I went out and tried your method but this time I just used my bare hands. I could “feel” things a bit better but still it seems quite vague where to stop turning the bolt. two of them had somewhat dirty threads and would get stuck. A little turn with the wrench and I could turn them by hand another 3/4 turn.
Anyway, I locked them down in some kind of position that is farther in than original. Seems like a good thing. I really wish I could see inside that box and see what the heck I'm doing. I'm a feeler gauge and micrometer kinda guy.
What is your opinion on both clutch and brake arms moving at the same time? Is that how it should work?
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I found that I had to chase the threads in the holes and on the bolts to get a satisfactory feel. It wasn't needed again after that.
If I had to guess the proper torque on the bolts to snug up against the band, I'd say 25 – 35 inch pounds to prevent dimpling.
The clutch and brake linkage rods will move simuntaneously, however the brake arms should not until about 3-1/2″ of pedal travel (the first 3-1/2″ is to release the steering clutch) at which point the brake linkage engages the brake arm and the rest of the pedal travel is brake and clutch combined. You must have a slotted piece of linkage at the end of the brake linkage rod to adjust this under the deck plates where this all takes place. I would make a removable section of deck plate because you will never be able to do this whole operation from underneath.
I'd probably call Eric's mechanic at least one more time and ask him how he did it without removing the deck plates. Zen maybe?
The simultaneous movement of clutch and brake arms would explain the squealing sound – clutch not fully released before brake application.
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The squealing sound was only one time. I haven't been able to repeat it. But if what you say is true, the brake arm sits still while the clutch arm is moving, then something is very wrong. I will shoot some video tomorrow morning and show you what is going on. Both clutch and brake arms are moving at the same time. i.e the pin is all the way aft in the slot always. That said, i should have brakes all the time and that just isn't the case. I'm getting the sinking feeling I should be calling the transport company and send this bad boy back up to Oregon.
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If I was there we could have it all done in less than an hour (except maybe for the deck plate).
The first portion of pedal travel is for the steering clutch only, that's why the slotted piece for the brake arm, the remainder of travel is for both. Sounds like that slotted piece needs to be adjusted way out more and the clutch lever adjusted in until there is only 1/4″ – 1/2″ of freeplay in the pedal..
Looking forward to the video.
From the manual:
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Nice video.
The clutch and brake pull rods are supposed to move simultaneously but the arms are not. The brake pull rod has a slotted “sequence fork” and pin to allow it to lag behind the steering arm.
I'm currently rewriting the adjusting procedure and removing the “Chinglish”. Should have it ready sometime today.
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Thanks bob. It's very hard to see in the video but it's not just the linkages that are moving at the same time. The control arms are moving too. The pin in the slotted sequential link is all the way aft when the pedal is at rest. Any movement of the pedal will instantly move both clutch and brake control arms.
Since this means I must have brakes starting to be applied as soon as I'm moving the clutch, the only natural conclusion is there is something wrong internally with the brake bands on both sides.
My next move is to tighten up the brake linkage so that brakes are applied all the time. This is just a test to see if there are any brakes on this machine. If I push in the clutch pedal the clutch should disengage and the brakes should be on full hard. That track should stop dead.
I am starting to suspect that one end of the band has come off the little rocker arm that holds both ends of the band. What holds it on there? Is there any way to inspect that connection without a total tear-down?
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Yes, I can see both arms moving.
“My next move is to tighten up the brake linkage so that brakes are applied all the time. This is just a test to see if there are any brakes on this machine. If I push in the clutch pedal the clutch should disengage and the brakes should be on full hard. That track should stop dead.”
This may not work if the steering clutch is not properly adjusted too, and you stand a chance of either peeling off a lining from the band or breaking a band anchor point. Maybe try it very cautiously?
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I can’t see anything else to do. Everything points to the brakes being over adjusted already. Moving the skirted linkage aft to make it “correct” would only give me LESS brakes and not more.
Or…..the other conclusion….there is something amiss with the bands or their installation. Is there an easy way to check if there is oil in there?
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I just can't imagine the bands being installed backwards, but I suppose it's possible.
Here is a pic of a new band. You can tell if this has happened by removing the top cover, and clutch arm linkage, and comparing your findings with the diagram in the manual.
Easy way to check for oil in the steering compartment is to remove the larger hex plugs on the bottom of the compartments.
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You won't necessarily feel the transition from clutch to brake, but the pedal should become slightly stiffer as you pick up the band tension. Adjust the brake so the pedal stops firm within 1″ of the bulkhead, that's why I suggested temporarily disconnecting the clutch pull rod.
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As near as I can tell they both seem to be working, and I heard the squeal from the right clutch. What I didn't hear was a change in engine tone when you went from right to left and back, but maybe that's just me.
Curious what you find when you check the drain plugs and pop the covers – hope nothing.
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“so those few times when I pressed the pedal to the floor and the track just kept on going is normal? “
No. If only the clutch releases you will still get some turning action (that's the way it's really supposed to work).
“hmmm guess I gotta rethink things a bit. The turning radius on this thing is huge if that's the case. My ram quad cab turns shorter!”
The dozer should be able to turn on a dime – literally. I couldn't tell that you had the pedals down hard. It sounds to me like the brakes are just not applying strong enough, assuming that the clutches are releasing enough.
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So to summarize:
1) Both pedals pushed in half way at the same time both tracks stop every time.
2) On both sides the clutch arm and brake arm are actuating simultaneously.
3) The pins for the brake arm are fully aft in their slots when the pedal is at rest.
4) the left pedal comes to a dead stop about the right distance from the bulk head but I'm not sure what is stopping it. It sounds like one of the pivots is hitting inside the tower. The right pedal hits the bulkhead.
5) The video shows me bottoming out the pedal every time. Sometimes the track stops nicely (I can even feel a bit of a jerk) and sometimes it just keeps rolling on like I did nothing other than release the clutch.
6) Most of the time I can't turn shorter than the width of my street..I'd say about 30 feet.
7) It seems to work better in 1st gear low box but even that is inconsistent.
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1) Both pedals pushed in half way at the same time both tracks stop every time.
That indicates the steering clutches are releasing properly, but maybe a little late.
2) On both sides the clutch arm and brake arm are actuating simultaneously.
Not right.
3) The pins for the brake arm are fully aft in their slots when the pedal is at rest.
Not right.
4) the left pedal comes to a dead stop about the right distance from the bulk head but I'm not sure what is stopping it. It sounds like one of the pivots is hitting inside the tower. The right pedal hits the bulkhead.
The left pedal should be a “soft” stop, like the brake on your truck. Right is wrong.
5) The video shows me bottoming out the pedal every time. Sometimes the track stops nicely (I can even feel a bit of a jerk) and sometimes it just keeps rolling on like I did nothing other than release the clutch.
Not right.
6) Most of the time I can't turn shorter than the width of my street..I'd say about 30 feet.
Not right.
7) It seems to work better in 1st gear low box but even that is inconsistent.
Yes, that is normal (not the inconsistent part).
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Here is some pics:
I've since removed the extra bits
I have a new theory however. These brakes appear to be in good condition. The linings are not slipped. But what I can see is they are tight as all heck. Is it possible two things are happening: one – the clutches are releasing late and two- the brakes are fading because they are heating? It doesn't seem likely in such a short distance. I've only driven the dozer for about two minutes at a time but if they were wound completely tight the whole time? Just a thought.
The extra bits in there are certainly not helping. They were not wedged in there so I don't think they were binding the band to the hub. If the bands were not wound so tight perhaps that would have happened. The funny thing is the bracket that was down inside the left brake box is the missing bracket he had to fab for the clutch return spring.
The other thing of note is that things are pretty dry in there. No oil or water that I can see.
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These brakes appear to be in good condition. The linings are not slipped.
They appear to be new.
But what I can see is they are tight as all heck.
They are maladjusted.
Is it possible two things are happening: one – the clutches are releasing late and two- the brakes are fading because they are heating?
Clutches are probably releasing late. Doubt there is brake fade due to over heating. I'm still working on the revised adjusting procedure, had a meeting today so didn't get it finished.
The extra bits in there are certainly not helping. They were not wedged in there so I don't think they were binding the band to the hub. If the bands were not wound so tight perhaps that would have happened. The funny thing is the bracket that was down inside the left brake box is the missing bracket he had to fab for the clutch return spring.
That looked like a 5/8″ grade 8 bolt in there, jeez! Good mechanics will mentally inventory the parts during disassembly and definitely check a compartment before buttoning it up.
Anybody know the best place to jack up and then block this dozer?Each side at the rear under the final drive housings (be careful about track clearance if you are going to run it), and under each side of the swing frame equalizer under the engine (again, watch the track clearance) and block up the blade under the cutting edge so it is not hanging against the lift cylinders.
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Yes, you can use the drawbar for a jacking point.
Swing frame is dozer slang for the track frame that holds the track rollers, idlers, and track adjusting spring.
The equalizer is that piece of steel that is trunnion mounted under the engine and connects the two swing frames together.
I was thinking that maybe it would be better if I just stayed with the Chinese terminology from the manuals instead of translating to American terms. What do you think?
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ok… the best I can figure for blocking. The front swing arm equalizer seems obvious. As near as I can tell the weight of the rear of the tractor is on that big round cross piece but I don't want the block on something round. The next best thing seems to be those brackets where the final drive casing is bolted. I would like to be able to get to the brake band adjusting bolt so I need to avoid that area. All sound good? I jacked it up and saw the tracks sagging by an amazing amount. Looks like the blocks will have to be at least 14″ tall!
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Perfect and I think that is exactly the problem. This picture shows the sequence link adjuster at the end of the threaded rod. No more adjustment to be had. The pin is STILL at the aft end of the slot. Sooooo that must mean the brake control arm is one or two splines off. Is it possible to remove and rotate the control arm without total dis-assembly?
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Ok, got the brake control arm off. Not too bad. The brake band jumped open when I got it off. It was under a lot of tension. So here is a video of the “as is” clutch setting. Looks to me like it could be tightened up a tiny bit but the puzzle to me is I was expecting to see it stay engaged a LOT longer. Oh well. press on. Tomorrow I'll have this clutch perfect and then see if I can get the brake arm back on.
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Member…not even Lifetime Member. Wow Bob, who's coffee did you pi&$ in?
To answer the question first, I'd like to see a nice clean procedure manual pieced together as all of us go through these things. I thought there was or used to be a “manuals” section on this site or the old one.
I just discovered a deviation that the owners of dozers with pendulum pedals have to contend with. So back to our main event…
Next discovery was the brake control arms are not symmetrical left to right. In my case I believe (and this is pure inexperienced opinion) the control arms were swapped. The picture below tells the story. On the top portion you see there is little to no clearance between the cotter key / pin and the casing. In the bottom pic is after I swapped the left control arm for the right. A lot more clearance. The problem was the pin wouldn't slide in the slot because the cotter key would catch on the casing. Now things move well. But that isn't the end of the story….
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Now, the difference for pendulum pedal owners… There is another adjustment point and in my case I think this one is key.
This adjustment I believe will change the ratio of movement between clutch and brake. I'm working on a drawing to show why and how. I've found that in my case, even though I rotated the brake control arm to move it forward in the slot, I'm still finding there is not enough throw in the movement to apply brakes fully. I'm going to work out the geometry but I think the above adjustment will fix that.
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Well…. It pains me to say it but I'm throwing in the towel. It's got me beat. The other adjustment is important as I thought however it's at the end of it's travel in the direction I need. So I'm done. Thanks for the help everyone. Bob really you put in some serious altruistic help there. I wish I could report better news.
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You can make the rod longer (or shorter) with coupling nuts (Available at most hardware stores).
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Needs to be shorter. If I had a set of metric dies I might give it a go but getting that rod out of the tower looks….interesting. Thanks for the suggestion but I'm all out of ideas. To be honest I can't really visualize how this is supposed to work in the end. I don't believe that pin is any more than maybe a quarter of an inch from the back of the slot when the pedal is at rest. The only way I could see anything else is if there was a way to pre-tension the brake band. No…this has to go to someone that has more time and experience than I.
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I'll work on a solution for you when I get off work in a couple of days. Might involve changing the slot length (not a good idea to pre-tension the brake band like someone did), or maybe slightly pre-loading the steering clutch. Let me work on this, meanwhile go have a cool one.
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I'm working along the same lines. I believe what is needed is more throw on the brake linkage vs the clutch linkage. My thought is to fab a new clevis that puts the brake rod on a greater diameter than the clutch rod. Before the dozer goes back I'm going to take a measurement that is needed: the distance the brake control arm needs to travel vs the clutch control arm.
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Thanks for the words of encouragement. I've purposefully avoided bringing up Eric and Keno Tractors. I don't think it's fair to malign someone without them having first crack at fixing the issue. To his credit he has been very prompt at putting me in touch with the mechanic that worked on this tractor. And that mechanic has been good at talking with me on the phone.
It made most sense for me to try and fix things first. After all, down the road it's going to be me alone that is going to have to keep this thing working. The difficulty for me personally is this is my first tractor of any kind and for sure the first one of these dozers I've ever even seen in person! So I have no road map to go by. I don't know what “working” feels like and sounds like. For me to fix something that I've never seen work in the first place is quite difficult.
It's still quite possible that even after they get it working, the performance will not be what I expected. I'm getting the sinking feeling these brakes simply don't work the way I expect.
Let's let Eric have the last word. The tractor is going back to him whenever we can arrange for it to be picked up. I learned a lot and now I know better what to expect.
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Grizz,
I'm sorry that I wasn't able to find a solution for you before you returned it, and I'm willing to assist Eric any way I can. I've done business with Eric before and can attest that he is a stand up guy.
The demographic that purchase these dozer's are almost always first time dozer buyers, and don't really know what to expect. These little dozer's are '60's technology and lack the sophistication of todays machines, which is reflected in the price, but they are an excellent value for the dollar compared to a comparable used machine.
Your expectations of the steering clutch/brake interaction is not unreasonable, however it will not resemble the later oil clutch/brake systems found on domestic machines. I know that once your machine is set up properly you will find it to be a very useful tool, and enjoy operating it.
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It will be in my driveway for another week or two before Eric can come get it. I'm the kind of guy that just can't let a problem lay. I'm sure I'll go out there and tinker as ideas come up. I did some drawings last night of an improved mechanism. IMHO I think there needs to be a separate adjustment for the ratio of clutch movement to brake movement. Right now it's given by geometry. I'm probably just making things complicated.
Your comment about it being '60s technology is actually a good thing. Have you tried working on your 21st century vehicle lately?
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I noticed I'm still “Lifetime” and “Elite”
Lifting off the cab is a piece of cake for me, working on the computerized crap, no thanks.
I know Eric is a stand up guy. His enthusiasm for his business showed through when I met him, and is why I bought from him. I don't know if this mechanic is his or someone else, I just hate to see it reflect on him and/or his business. Buttoning up a job with “pocket parts” inside and not test driving after repair just doesn't sit well with me.
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I was able to make some detailed measurements this last weekend. I'm now convinced that the detail shown in post 61 of this thread is most certainly NOT correct (on my dozer at least.) The total travel of the connecting rods (both are the same) is 1.5″. That is from top of pedal stroke to bottom. There are no adjustments I can see to change that. The slot in the sequence fork is almost 2 inches long.
Even worse. I measured that the brake arm needs to travel about 2″ +/- 1/4″ before the brake begins to grab. I did this by hand so it's when I feel the arm get tight. This distance combined with the two inch slot means the control rod would have to travel almost 4″!
not even close.So, IMHO, the brake arm must be “pre-loaded” about an inch of it's travel when the pedal is at rest. I think this is ok since the brakes won't be “on” yet – it's just taking up the slack in the mechanism.
The other thought nagging me is this “two inches” of travel for the brake arm might not be normal. I wonder if the brake bands that are on this machine are the wrong length.
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OK, now I think I know why they abandoned the pendulum pedal system (based on the assumption that all of your linkages and pedals are assembled correctly), but I believe I have a work-around solution and will start building a working model for you tomorrow. I start my day job work week tomorrow, so it's going to be a few days. You got me going now. Mr. Pythagoras will be my assistant.
Your total pedal travel is 7″, correct?
What is the total linear travel of the brake rod? You need ~5″ from full slack to full application?
What is the total linear travel of the steering clutch rod? How much travel do you need for full release?
I'm sure the brake bands only come in one size, but they can be shortened – not something you need to be doing.
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I appreciate the effort Bob. The tractor is still going back to Keno to see what they can do with it but in the mean time, I'm like you – just can't let it lie.
The thought I have about increasing the throw of the linkages is that I will be decreasing the mechanical advantage by the same ratio. If we go from 1.5″ now to let's say 4.5″ that's a 3x reduction in leverage! I'm already stomping on the brakes and it won't stop!
Here is another nagging thought though: I ultimately found two things:
1) The brakes were nearly full-on all the time
2) The clutches were releasing only a little late but were fully released I'm sure when I pushed the pedal all the way down.
Doesn't this mean those tracks should have been stopping on a dime every single time? Something still doesn't add up for me.
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Has it really been that long? Gosh how time flies! No I haven't sold the dozer but life has also gotten in the way of making much progress.
Steve – Bob does ask a crucial question…. Do you have the pendulum pedals like mine? I think there is a good reason they moved away from that style and you and I are experiencing it.
For those that are interested…. The last rebuild improved things quite a bit but they still are not perfect. The clutches were replaced with factory new parts (drums replaced at the same time.) When I got the dozer back it still didn't turn quite to my satisfaction but it was much closer. I added about two or three inches of threads to one of the linkages and that let me dial in the clutch. Life got in the way and I have yet to do the other side but I believe it will fix that side as well.
One significant drawback to the new clutches… I have to just about stand on the pedal to get it to release. I'm by far the only one in my family that can drive the dozer now.
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Glad to hear you still have it.
The release of the clutch packs should be relatively effortless unless they put some monster springs in them.
Could it be that there isn't enough pre-loading of the brake band, and you are coming to the end of the clutch release yoke travel? Just a thought.
I know what you mean about “Life”. I have yet to make those dozer maintenance videos.
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Bob and Shannon, thanks for the reply's… Shannon, just sent you a reply PM before I saw you had reposted.
My issues seem to mimic Little Grizzly's somewhat… the brakes never seemed to really engage/turn like they should, then after throwing a track one day, I put it back on, and “viola” dozer wont turn. To make it worse, left brake does nothing when applied, and right brake ceases both tracks when applied.
And yes, they are the foot pedal style. I'm in Chico, CA, and beginning to believe this may be out of my scope, so now trying to (A) diagnosis the problem and (B) find somewhere somewhat local that can address it… Naturally it broke right in the middle of a huge project!
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huntinaldy wrote:
“… the brakes never seemed to really engage/turn like they should, then after throwing a track one day, I put it back on, and “viola” dozer wont turn. To make it worse, left brake does nothing when applied, and right brake ceases both tracks when applied.”
Well, I guess you know that there is no correlation between re-installing a track and the dozer's ability to steer.
If I understand correctly, when you fully depress the right brake pedal the dozer comes to a stop – it doesn't try to steer to the right. When you fully depress the left brake pedal nothing happens and the dozer continues on a straight course. It sounds like the brake pedal cross shafts could be frozen together (alas, there is no lube point). Does the left pedal move when you depress the right pedal?
The first thing I would do is remove the steering compartment drain plugs and see what comes out- they are large hex plugs located just forward of the lower brake adjusting bolts underneath the dozer.
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Thanks Bob… will check the steering compartment drain plugs and see what comes out. And yes, dozer comes to a complete and immediate stop when right brake is applied… which I thought weird as it is my understanding that the brakes operate independently of each other… will check drain plug and brake pedal cross shafts.
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…. checked brake pedal cross shaft, found lots of dirt packed up underneath the shaft, cleaned it out… no change. Located the plugs and removed, picture shows what I hope were the right plug(s) and what came out…
… look right?I fired it up again, pulled off the blocks, and no change. The right brake completely stops the dozer, both tracks, forward and reverse. The left pedal feels like it is trying to “grab”, but does not stop either track… could this not be a brake issue at all and possibly a clutch issue? I”ve got a call into Keno for help but haven't heard back from anyone yet … frustrating.
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nope… when the right pedal is depressed, the left pedal remains in its position. The pictures are small, the material that came out of both drain plugs, I assume is just dust/material from the brake bands.
Am I correct from reading previous posts, that there is no easy way to get to and inspect the brake bands?
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You can inspect them by disconnecting the linkage and removing the top cover. If your dozer is equipped with the optional FEL then that is a little more work due to the extra hoses.
If the dozer comes to a complete stop without killing the engine when you only depress the right pedal, then something in the left drive train is broken. So without knowing for sure, I'd say you threw your left track.
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… finally got around to getting the dozer on blocks and testing the drive train. Sure enough, once put into drive, right side moves normally but the left doesn't move, and only occasionally “twitches” like it is trying to go forward…. good news is this ruled out the brake issue, bad news, looks like I have to tear into the final drive to see what's broken, thanks for your help bob, may be calling on you again once I identify whats going on….
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Hi, I am Al Lamore and have quite extensive experience with this style of dozer/front loader. If you think it's the Bull Gear or ring gear, take the seat off, remove the top cover from the transmission and pull it to the side. I had a bevel and ring gear that went out. I replaced the bevel gear shaft and the ring gear. Used white substance that mechanics use
to get the proper spacing pattern print as in the manual.
I wrote a repair manual on this. Had to remove the tracks, pull
the two final drives, etc. Never had a problems after fixing it. You will
also see the steering clutch packs when you pull these two final drives off. Take pictures of everything, like I did, so it gets put back together right. I have been into every part of this machine including the shuttle clutch, motor, transmission shaft replacements, motor, etc. I have figured out how to improve the defects of the shuttle clutch, to rebuild drive splines, etc.
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Now to find the right parts…. anyone know where I can get a manual with part numbers ASAP (already emailed Yuchai twice, and called Keno)… Looks like I am going to need a whole drive shaft assembly, seals, bushings, bearings, etc… Looked at Circle G website, and will price through Northern Tools… any other suggestions on places to find these parts??? not looking forward to what its going to cost… appreciate all input.
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I think Northern and Circle G will be your best bets, aside from Yuchai directly. Yes, you have it right on the parts – all seals, gaskets, bearings, and shaft.
Thought you had one already. PM me your email address and I'll send you a PDF copy of the parts manual. Do you need the operator's manual too? It's as close to a service manual as you can get.
Just be glad it's not a big Cat, you would be up in the medium five-digit $ by now.
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If these dozers came with decent rock guards and shields, none of that would have happened, so you have to be extra careful and watch for large rocks and logs getting jammed between the sprocket and track.
I would also pop that pinion bearing cover and inspect for metal particles.
Nice work btw.
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It's been a very long time but I thought I would close this thread with the final results.
After getting the dozer back from the mechanic for the second time (and being promised they checked it and it works great) I drove it a little bit and found the new steering clutches, brake drum, and brake bands were not working at all.
Same problem as before, the clutches were not releasing correctly and the brakes wouldn't harm a fly.
After being distracted by family life for a year or so I finally got out there and after a few deep breaths started in on it all over again. This time with success! I found some basic things wrong like the brake adjustment bolts at the back of the tractor were not long enough to put the bands in the right position. I also pulled out the brake control rods and added about two inches of threads.
After spending many hours of making small adjustments to the clutches and brakes I have what I would call a working dozer!
Since then I've fixed many of the other little things that the “mechanic” did wrong – like attaching the blade tilt lines backwards
and other such nuisances .I really want to thank the people here for being patient with me and teaching me so much. I would have given up a long time ago had it not been for you guys and this site.
I mixed feelings about the shop I bought this dozer from. On one hand the owner really did try to make it right. He spent a lot of money getting new clutches, drums, and brakes as well as the time and effort. So good feelings there. On the other hand they did so many inexcusable things. I mean if you look back in this thread: there was loose bolts down in the brake drum area (and my loose I mean just tossed into the compartment), completely non-functional steering, strainers where hydraulic filters should have been, sand and gravel in the hydraulic tanks, a piece of linoleum flooring as a gasket, a dipstick that is rubbing against a gear, I could go on… The worst comment from the shop owner was, “you get what you pay for..”
So at this point I finally have a working dozer! It seems like a good strong machine once I ironed out all the kinks. Thanks again everyone. Happy tractoring!
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Hello good people,
Here we go again with a recurring problem so I thought it best to continue this thread. My dozer has sheered the final drive output shaft in identical fashion as the photos in Steve’s earlier post. I recall another member also suffered the same problem a few years back. I know my break wasn’t caused by a foreign object getting caught in the tracks as I was root-raking regrowth on clean ground when I suddenly lost left side steering. Fair to say my machine gets pushed to the limit with the attachments I’ve made for it and the tasks it performs so it’s probably been a component failure in the making for some time. Luckily the dozer was in an accessable area for the 17 ton excavator so I was able to pick it up and carry it back to the shed for repairs. Now the question is what to do about it?
I am hesitant to only replace the broken output shaft as it appears there is a design flaw and the same component failure is destined to reoccur. Now I am toying with the idea of retro-fitting a smaller diameter drive sprocket. To my way of thinking this would lessen the tortion force applied to the final drive output shaft (axle) and reduce the likelihood of twisting it off again. Any engineers out there who can confirm or negate this reasoning?
A smaller drive sprocket would require some additional modifications to accomodate it, namely converting the undercarriage to a high-track of sorts. My existing steel tracks need replacing anyway and I think it would be foolish to replace with the same rapid-wearing dry pin Yuchai track links. These days there are skidsteer loaders utilizing steel tracks in a high-drive configuration (see photo). I might be able to get a second-hand set from a parts wrecker. Raising the whole machine 300mm means the blade lift rams would need end extensions or longer cylinders and a smaller drive sprocket means slower drive speeds also. Food for thought, ideas / suggestions anyone?
Dozer YCT306S shuttle shift - root rake, tree-pusher, backhoe
Excavator Hyundai 17 tonQLD, Australia
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The little Yuchai “Hy-Track” is a tiny little two cylinder tractor, not built for dozing work but rather strictly for pulling implements through rice paddies and orchards. The nice thing about the Hy-Track configurations is that the final drive components are in the sprocket hub, namely a planetary gear set (just like the excavators). At one point I was considering completely gutting my Yuchai dozer’s entire drive train and installing a hydrostatic system from a skid steer, but it only made it as far as the drawing board before life got in the way. You definitely could swap undercarriages with a Hy-Track skid steer, but from the skid steer boards I’m on, I see those guys are not without problems either. It would be an expensive proposition without any promise of ROI.
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Expensive is the quote I received for a new set of Yuchai tracks – $5,300AUD plus shipping and I will end up with the same problem. Not going there. Second hand steel tracks good condition from a 3.5 ton excavator advertised online for $2200 ono. It’s an option worth investigating further, I will let you know how it goes.
Firstly the whole backend has to be stripped, cleaned and rebuilt which will take a few months. Tasks include LH final drive total rebuild, RH final drive oil seals, Bevel gear housing oil seals and shuttle clutch rebuild. Other issues needing attention are leaking hydraulic control spools and the injector pump is sucking air someplace. The steering clutch plates are covered in rust and dust (not oil). What product is best used to clean and keep them rust-free?
Dozer YCT306S shuttle shift - root rake, tree-pusher, backhoe
Excavator Hyundai 17 tonQLD, Australia
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Good call Bob!
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