SN: 29Y01769 My 931B has wet brakes/clutches. My manuel only shows dry brake procedure (the one with the support bolt underneath). My question is are the procedures the same for wet or dry? Seems I have to press the pedals to the floor to make it turn. If I tighten the brakes to where it turns good, the brakes start dragging in 2nd gear (maybe I just don't notice in 1st). The rollers on the clutch release valves are good and clutch release pressure is 390 so I believe it is just brake adjustment. Thanks
What is the reference of the manual you are using.? SENR5334.?
Attached the OEM Manual. Maybe it might be a little more clear.
Thanks Nige, I will give that a try.
Nige, just to verify, will that work for my machine, I believe mine is about a 1985 model?
All service information is based on machine Serial Number, not model year. The information I uploaded earlier is what is listed for your Serial Number therefore, in the absence of any information to the contrary, I believe it to be correct. YMMV. There are other setting/adjustment procedures but all of them are for the dry brake setup with the support bolt underneath the brake band. I also found the attached after another search that may help.
I think the adjustment is the same for wet or dry but with wet it's very important that the bands aren't too tight when the brakes aren't applied. They will wear into the brake drums. A former Cat foreman who sadly passed away a few years ago (Bob/Ont) told me an easier way to adjust the brakes than measuring all the linkage. It should be in the archives on here but basically you remove the pin on the long rods that goes to the "humps" on each side of the final drive case. They should have a hairclip on the pin. Then tighten the brake bands snug. Not super tight just snug. Then shorten the linkage as much as possible that the pin on the long rods can be put back in. Then you loosen the brake bands to get the freeplay and set the pedal height for engagement. This guarantees that the free play is at the brake bands and not in the linkage. I think you loosen the brake bands 12 clicks or about 3-3.5 turns. Better to have more freeplay than not enough. Machine should coast to a stop when adjusted properly or roll on a slight incline. Should only need light foot pressure to turn. Both pedals pushed half way or so should stop machine and coast the same as if you shifted to neutral while moving. A little firmer on the pedals should apply the brakes.
I appreciate the reply very much. I will certainly look at that. I may get a chance in the next few days. Thanks
Look under 931B brake adjustment. You may have to loosen the brake bands 4 turns. You don't want them dragging.
I looked at the brake adjustments a little, but I may have a different issue. Let me give a little history : Bought about 3 years ago Would barely steer because of flat rollers (replaced and worked good) I have always had to press hard on the pedals. Last month I replaced the track chains, and while I had it on blocks, I noticed that when pressing the pedal to get full travel on the clutch spool, neither side will disengage. The brake will stop the track. When in gear both pedals pressed half way, machine starts to move at about half throttle. Pressure is 380 coming out of the clutch release valve (I didn't have the right size fitting to measure at the plug in front of the sprocket, so I measured right before it goed to the clutch case) I ended up taking both clutch case covers off. When I move the clutch release cam (with my hand) the release piston in the case pushes the yoke out all the way to the stop but the tracks keep turning. Both sides the same. While driving with one pedal half way, the machine still makes a slow turn, but it's like the clutches are not fully released, therefore more brake required during turns. So, my way of thinking (no expert) is the clutches should 100% disengage.
IMO the clutch on either side ought to completely disengage at some point as the pedal is going down before the brake is fully applied. Maybe the attached document might give you some direction on how the power train is supposed to work and how to test/troubleshoot it.
My only thought is in the old days when you had steering leavers and brake pedals I believe the operator manual said you got a gradual turn by just pulling the steering leaver and a sharper turn by applying brakes also the clutch may be fully released but I’m sure you would get some amount of drive because of the oil between the plates and discs
I guess that would be my question is how much drive should I have. Seems off that is enough to move the machine, but I just don't know. I belive it's been doing this ever since I've had it, I just always thought the brakes were weak. Wasn't until I had it on blocks that I noticed full disengagement still moved the tracks. But it may indeed be proper operation.
I’m wondering when we did oil clutch conversion on old 931s you had to bend the yoke possibly some one changed clutch’s and has a miss match also there is a measurement for the stop bolt you could check
I didn't know the yoke had to be modified for the conversion. When I had the clutch case covers off I did look at the stop bolt, the book called for 8mm. It was hard to measure it where it is located but it is close.
I wonder if with wet brakes there's still some friction from the oil that the sprockets/tracks could still move some with the clutches released when up on blocks/no load? I only mention it because a good way to tell if your clutch is good on a dirt bike is the back wheel will turn in neutral when the bike is on a stand idling. It will turn a little faster with more throttle too. Also when putting in new clutch plates it's important to fully soak all the clutch plates in oil before installing them. If you don't your clutch won't work until they're wet enough. Can be a little scary when you pull the clutch and it doesn't do anything. I had it happen once when an experienced Honda mechanic who didn't normally work on dirt bikes offered to do my clutch in exchange for some skid steer work. Went to a race and had to do half a lap in practice before I had a clutch. The worst part is the mechanic said there were more loads of dirt to spread than he thought so cancelled our arrangement without telling me. I didn't care if I had to spread 6 loads instead if 4. I was there anyway. To make it worse he filled out a work order and charged me full retail price for parts and labour. The owner of the shop was a good friend and had no problem if a mechanic did some outside work on his own time. It really ticked me off because I thought we had a deal. Then when my clutch didn't work I thought it was ruined and I'd have to do it again. I hate when people make a deal with you and then back out!
Thanks for the info. While I had the case covers off I wish I would have adjusted the stop bolt to get more travel of the yoke to see what it would do, but I was worried about causing problems. That would be the only fix, apart from something being internally wrong with the clutch pack. I adjusted the brakes like you mentioned, and I still have to really press the pedal to make it turn. (Been like this since I've had it) There has been a few times after a brake adjustment, I think I had them dragging a bit, then only a light touch of the pedal would lock the brake and turn great. I was worried they were heating from dragging, so I backed them back off to where I press hard. Then the tracks don't come to a sudden stop with brake applied, but a gradual stop as I'm standing on the pedal. That's how I have been using it.
Especially with wet brakes you shouldn't need much pressure to stop the tracks from turning. I'd look more into the steering clutches to make sure they're fully releasing. If they aren't the machine will power through them and keep going straight. My dry brakes don't need much pressure at all to stop the tracks. Yours should be at least as easy.
I guess I may take the case covers off some time and adjust the yoke stop bolt. Other than that it has to be internal and I don't see myself pulling it out to inspect it. If more yoke travel doesn't fully disengage it I will probably just keep using it as is
I'm not so sure the stop bolt adjustment is the problem.
I've read other places that the clutch stack could be too thick to release. I have no idea if or when they have been replaced. I feel like I would be better off just using it till something really breaks. Just a farm machine, clearing some land for pasture. Seems all the slipping from brake use would eventually get it within limits
The steering clutches could be worn out. The problem if you wait until something really breaks or just stops working is it will usually cost a lot more to fix. If the brakes wear through the drums, new drums aren't cheap. It's much better to fully diagnose what the problem is in order to save on repair costs. You can check the stop bolts but I think it's a bigger problem. Hope I'm wrong.
Nige would you mind sending me the steering clutch removal and rebuild procedure? Thanks
Nige would you mind sending me the steering clutch removal and rebuild procedure? Thanks
Pulling the clutches out isn't too big of a deal but having a helper makes it a lot easier. The book says to loosen the fuel and hydraulic tanks to tilt them out slightly but I found it doesn't make much difference because they hit the ROPS right away. I hung a come-a-long from the ROPS and twisted/tilted the clutch assembly sideways to get them in and out. I used a 1" nylon lifting sling around the clutch assembly. I think it was 3 or 4 feet long. You need to remove the bung like plug above the sprockets to get at the outside bolts holding the clutches to the final drives. I had the machine lifted up and used a prybar to turn the tracks to take the bolts out one at a time. There's 4 inner bolts that you have to have at the top to remove. You have to make it so the last inner bolt is at the top when you take the last outer bolt out. The clutches require a press and special tooling to take them apart and put back together. From what I've read/heard if you press too hard you can break something. Best to have done by a qualified shop. It was about $3500cad. a side when I did dry clutches several years ago. I also had a brake shop put new material on the brake bands. The hubs were good. Kind of expensive but it's like a new machine now. Very easy to steer.
look at this thread might help you Cat 931 Steering Problem Thread starter sergioannis Start date Apr 4, 2025
Here it is. HeavyEquipmentForums
Thanks guys. I checked the thread out. Seemed like @sergioannis , if I read the thread right, his yoke wasn't moving. I just put 3500 in this thing for new chains and sprockets, so I can't let a shop do the clutches right now. I just wonder if the guy I bought it from had the clutches done and maybe the stack is too thick. Seems like it has to be too thick, throwout bearings worn, or the stop bolt/piston linkage adjustment. I can adjust to get more yoke movement easily, but that probably won't fix it. And remember, both sides are the same.
Two things that could be a problem a lot of play on the balls on bottom of yoke, throw out bearing bad or nut that holds the bearing being loose
Good thinking. The clutch case covers are back on now, but I left the battery tray out, so I can have the covers back off in an hour. Don't know when I will get a chance to look at it again but if you guys think of anything else let me know, I appreciate the help.
I put new bushings in for the balls on the yoke but don't think I needed to. I had to cut a slot with a torch and use a chisel to get them out. Didn't have any dry ice or nitrogen so had to pound the crap out of them with a brass hammer to get them in. The shop that did the clutches suggested I use dry graphite on the balls instead of grease because grease would attract dirt and other debris.
You would think I wouldn't have much wear in joints like that being everything is bathed in oil but who knows.
Certainly. See attached. Start from Page 14.
Thanks Nige, and if I could trouble you once more, can you send me the yoke stop bolt adjustment. My manuel says 8mm clearance, I just want to make sure that is the same for wet clutches
8mm is 5/16" if you don't have a metric tape measure.
You'll find it in Step 12 on Page 22 of SENR7918-02 that I uplodaed a couple of posts back. That is in the section that specifically refers to wet clutches.