Hey guys. Hoping you can help me sort a strange a couple of issues out. I just bought this machine a week ago. Was using it when I noticed the right side track would come to an immediate stop & “bangs” loudly when trying to steer with right pedal. The middle brake is basically all stop, not much in the way of “feathering” to a stop. Pretty sure the Serial number is 25Y01728. Definitely sure it starts with a 25Y, though. I have yet to open up the floor to check for obvious problems or check any fluid levels. Any help is greatly appreciated. Thx.
These are the best pictures I have of the machine right now. In case it is needed to help establish what year it was made.
That does look like a good S/N SIS shows this: 931B TRACK LOADER Machine Serial Number - 25Y01728 (Build Date - 14/11/1982) Note that Cat build date format is day/month/year I have access to SIS but no direct knowledge of most track machines so hope someone else can chime in. If you need a systems operation or other information I might be able to access that much. Just on the chance the last owner left it in there check behind the seat to see if there is a owners manual in a pouch there.
I'd start with a brake adjustment. Adjust brake bands tight then back off 1 and 1/2 turns. Adjust brake rods as short as you can and still get the pins in the rod ends.
Ok. Will try to get that done very soon. Was just working on it yesterday replacing the sand trap / air intake pre-cleaner & both engine air intake filters too. Will check all fluids once I get back out to where it is. Thx guys.
Check the rollers on the steering clutch actuators. It could be the steering clutches aren't completely releasing and causing the brake to grab while still trying to go forward. Just to clarify on Old Magnets post, tighten the brake bands up and then adjust the linkage as tight as possible while still being able to put the pin in the yoke. Then back the brakes off 1-1/2 turns and that assures the free play is in the brake bands and not the linkage. I think there should be about 3"-3 1/2" free play at the pedal. Bob/Ont told me that several years ago and it's fool proof. You read the Cat manual and you have measure the length of every rod in the linkage. Bob was the expert on these machines and is sorely missed. I have 25Y01916.
I'm hoping to be able to get out to the loader again very soon. As soon as I do, I will be certain to adjust these brakes. I should probably ask where these adjustments are before I go on a wild goose chase thinking I know where to be looking for them. Are they located back beneath the battery? Or, located just below the floor plates?
On early s/n's the brake adjuster is under the small cover plate just ahead of the lever housings on the cover plates. If it has the oil clutch/brake option the adjuster started out below the cover plates then changed to protrudes above the cover plates.
There are bolts on the bottom of the machine to hold the brake bands up if it has dry clutches. The adjusters are under diamond shape covers beside the seat. I think some machines had extensions sticking up but likely under the covers and you need a socket and extension. I can't remember the size though, Spray the adjusters good with penetrating oil as they could be rusty or stiff.
I was able to look under the machine on Saturday. I did NOT see any bolts from the underside going into the steer clutch areas. I did see fill plugs for each steer clutch housing & fill plugs for final dives too. I did find three drain plugs for the bevel gear & steer clutches on the bottom of the machine too. I was NOT able to actually work in the machine though. I will try to ad just the brakes & remove floor plates soon to give more feedback.
I did NOT find an operators manual left on the machine. I am guessing that would be quite rare.
I think it's fairly rare to have wet brakes on an earlier machine but could be. Look in the archives on here Wosama031B has wet brakes on his 931B.
Typo, that should say Wosama931B. The bolts to hold the brake bands up on dry clutches have a pipe around them to protect them and could possibly be packed with dirt. If you do have wet brakes you have to be really careful you don't adjust them too tight or the brake bands will chew into the drums. Bob/Ont has posted about about it in the past.
This is what you'd be looking for if it has dry brakes (support screw) Oil type steering clutch and brakes would have been available as an attachment.
I don’t remember seeing anything like that so near the final drive drain plug. I will try to take a good picture of what is on the bottom of my machine. From what that picture shows. It would seem as though areas would get damaged quite easily if running over concrete of larger debris. The drain plugs I did find were towards the very rear of the machine, within 8 - 8 inches, or so. I would also assume that a wet steer clutch would be far better from a wear perspective as well. How clean / what color should this oil / fluid look, if everything is in good shape? Honey golden? Clear?
If it has dry steering clutches there will be five shielded items all in a row. Center drain plug for bevel gear compartment and one each side for steering clutch drain, the other two being shields for the brake band support screws. From your description machine may have oil clutches. Oil could be as you state, just not black or have water mixed in. I misstated on the brake adjustment. If it has the brake band support screw tighten until the band just touches the drum then back off 1-1/2 turns. For the brake adjustment turn until tight then back off 3-1/2 turns. Brake pedal free travel should be 5 to 6 inches.
Hello, when i start my old 931b, give a few minutes to warm up ,then i go straight forward and back a couple times to get the fluid moving, and even with the new track will be stiff. Also you may need a few rpm to get the pressure up enough. Also get to know your machine, look very closely at everything. Take photo before removing parts. You probably know all now. Good luck
UPDATE: ok so this took a long time to get around to, but I did pull up the deck plates. I checked both steering valves for the little roller being present. I did not find anything obviously bad or missing from either steering valve. I suppose the next step is either taking hyd pressure readings or just rebuilding the steering valve for right side. I did verify that this machine still steers HARD when steering right, but does not do it when steering left. Tried to determine if left pedal goes any further forward than the right pedal does, they seem to travel the same amount. I'm pretty sure the brakes are adjusted equally, I will have to revisit the machine to see if there are any brake adjustment bolts under the rear of the machine very soon. Any further thoughts in the mean time?
A Service Manual might be a help. Here's one I found (SENR7925 - a new one is $550 BTW) https://www.ebay.com/itm/CATERPILLA...op-Service-Manual-CAT-owner-book/192897675580 Here's a Parts Manual (SEBP1247 - $90 new) - https://www.ebay.com/itm/CAT-Caterpillar-931B-Track-Loader-Parts-Manual-Book-Catalog-29Y-crawler-spare/200553496814?_trkparms=aid=1110001&algo=SPLICE.SIM&ao=1&asc=40718&meid=9c0ba421e4e14f468c5d71063cf824fb&pid=100623&rk=1&rkt=6&mehot=lo&sd=192897675580&itm=200553496814&pmt=0&noa=1&pg=2047675&_trksid=p2047675.c100623.m-1
My machine does have the same number of five "protected" (pipes) areas underneath of my machine. I Will try to adjust the brakes first & report back what was found.
I tried to purchase that manual, but it is all ready unavailable, I suppose somebody else got to it before I could.
Hello sir , I hope you are having a great Christmas . You have to adjust the top and bottom at the same time . There is a leaver that can wear to oblong hole , and some have a bearing that can wear . always a good idea to look over the linkage . good luck , sam .
Ok guys, here is the final update on this machine. I was looking over the rear of the machine & found the right side adjuster “screw”, caterpillar parts diagram calls it, completely missing. I assume that “it just fell out” some time before I bought it. I chased the threads on that hole with a standard 1/2”-13 bolt to ensure all threads were ok. Then moved on to the left side. The “screw” Was seized in place. So I used a cutting torch to carefully warm that whole area up carefully. I eventually got that old screw out & chased those threads as well. I replaced both (2) screws & adjusting nuts, as per the directions found on this site. I just thought that everyone who chimes in would fully appreciate an update on this issue. Immediately after finishing up this brake repair / adjustment, this machine was transported to the new owner about 90 miles away. I did ensure that it no longer banged when steering. I had no real good way to determine if the left side was properly adjusted to begin with as the transporter was waiting on me to walk it over to him, that was on 3-16-2020, this past Monday. I did just want to say thank you to everyone who contributed to me ultimately repairing this issue. I hope this also sets a trend for other guys to reply with what actually helped repair their machine as well. Cheers to all! Thanks a million!!
Which bolts/screws are you talking about, the bolts to hold up the brake bands? They just support the brake bands so the top doesn't ride on the drums but don't do much with brake adjustment. I have read that some people leave them out so that any water in the clutch housing will run out. I think a better idea is to put anti-seize on them and take them out occasionally to drain any moisture that may have got in the clutch compartments.
yes. I was talking about the actual bolts that hold up the brake bands in close to the brake drums. I think I have heard of other guys leaving these bolts out, as you have said,, but there were (3) drain holes on the bottom of my machine, plus two (2) more for these bolts to do what they were designed to do. The buyer was an 81 year old lover of old iron & I knew he was my buyer when he started to walk around it. he said that he had one before & regretted selling it.