Ok here is the deal. Purchased a case 850 from a guy off Craigslist he said the under carriage had just been rebuilt along with the tq converter he gave me a bunch or receipts and stuff so it seemed like a good purchase and in good shape. I am new to dozers so please bare with me, but the issue I am having is I was working the dozer moving some dirt and it worked fine for me most of the day and I shut it down and went and got my truck and trailer to load it up. Upon my return I go to load it up and all of the sudden the left side brake quit working and wouldn't allow me to turn the machine left. As u can imagine this made loading it very sketchy but I managed to get it home. Not really sure where to start looking for problems. There is a definite difference in the 2 pedals the side that works feels normal and I can feel it grab and has a little play in the pedal but the left pedal is just hard and I cannot apply it. Any ideas?
If the 850 is like the 450 the brakes are a disc type pushed on by a ball roller cam.When the cam reaches max travel the pedal just gets hard.The first part of the travel should unlock that track.That is done by a hydraulic valve under the seat.Brakes were the weakness of most of the older cases, and it is unusual to find them in good working condition.Most guys turn with the HI-LO range levers.And sometimes the brake disc splines just strip out.
Thank you for your reply. I use the high low levers to turn but in like to use the brakes when loading and unloading onto my trailer. I'm a little unclear if you gave me a suggestion for a solution I found the hydraulic control valve under the seat are you saying I should be able to unlock the brake by messing with the valve? I was thinking it was a frozen piston in the master cylinder but I removed the brake line and the pedal started working normally and would go to the floor and not just stop completely after a few inches like it had been but I reconnected the line and it went back to the way it was. I think I made a mistake because now I need to figure out how to bleed the brakes along with fixing the initial problem. Just thought I would search here for answers before bringing in a mechanic
What I'm telling you applies to my 450.I think your tractor is the same setup.You will need to pull the left brake housing,It's under your left floorboard,round cast housing with the rod going into it.It can be hard to get to a couple bolts,but once it's apart you will find it is quite simple,and parts are not to badly priced.
Ok I'll check it out tomorrow thanks for the help I couldn't even find anything that resembles a brake just been kinda lost. Tried reading the service manual but it isn't much help
Once you get in there,I you will find it a big help to have access to a bead blast machine
Brakes ? You don' t even need brake pedals on a 450 or 850 , I removed the pedals completely off both of my 450s , you steer case crawlers with the levers , true enough the pedals are for quick turns , away from trees , basement walls and such . If you do not know much about the brakes ,they can get you killed . Loading case crawlers on trailers is the most dangerous thing you can do using brake pedals . If you push the pedals half way , you will free travel , pedals must be pushed all the way. You are suppose to steer with the levers PEROID !
Pretty new to dozer operations so still trying to get used to all of this, but what about unloading the dozer I use the brakes to bring the machine off the trailer because once the trailer tilts if I'm not on the brakes it's just a free fall and that just seems dangerous so my question is do I just let it free fall off the trailer?
Back off in low range reverse and as you seem to pick up speed push levers into forward as you also push on you fuel pedal as not to stall engine , it will take you some time to get the feel . When you do , tell me how simple this is . Now don't go off side ways and get hurt . Why don't you practice loading your 850 , if the trailer is still tilted leave your levers in forward and ease off your fuel pedal as to let the transmission slip and you can control your speed off of trailer . Start at bottom of trailer , third of the way up , get the feel .
IMO depending on the trailer,loading and unloading a dozer with no brakes is dangerous,and not for a student driver.It is done every day I know,but there is no safety net if something goes wrong.If your keeping the dozer,fix the brakes!
Welcome to HEF Manny530! I'm guessing 2 things 1) your brakes may need an adjustment - item #32 is the adjuster - you want about half pedal height when applied. 2) left brake return spring is probably broken #36 TIP - Steer it on the levers whenever possible & only use brakes for tight maneuvering - keep wear on brakes to a minimum, they are ugly to fix......
Thanks for all the help I was issuing the brakes to turn from time to time but will definitely cut back. I'm going to get the brakes fixed regardless just because I'm the type of person who doesn't like thing to be broken and not working properly. Plus I need them for unloading and loading because it is not fun loading and loading on my trailer without brakes. This may sound like a dumb question but where is the brake even located? I've looked under the seat but can't find anything that resembles a brake. I was gonna pull the bottom skid plate and maybe I could then see something that resembles the pics in the manual
Pull up the floorboard under your left foot,the round casting under there is the brake housing shown in the picture above.
when I pull the floor board. There is a l thing with the 4 bolts holding some sort of cap and it has a large hydraulic hose going into it so I assume it's a filter housing of some sort. I see some other stuff under it would that be the brake?
The brake housings are mounted to the front of the transmission, one on each of the drive shaft. You can trace your brake lines from the master cylinder back to the brake slave cylinder which is mounted on the brake housing. Like alrman said, they are likely in need of adjustment. Hope this helps. Chris
I followed the lines from the master back and they go into the hydraulic control valve and I don't see any smaller lines coming off of it they are all larger hoses.
Is it a straight 850 or is there a letter also. (850B, C, D, etc.) Serial number would also be helpful Chris
I meant one on each side of the driveshaft. Oops
After a few minutes of thought I remembered how mine is set up. The lines from the master cylinder go to the control valve where they hydraulically shift the track to neutral. There should be two steel brake lines coming from the lower front of the control valve going down to the slave cylinders. Chris
If I may add a few comments. I own a 455c and although the brakes had some advancements including oil filled brakes on the really late models, to my knowledge they are similar through the range. Mine had a weakness where the links that pulled on the disk would separate and break the split pin resulting in no brakes. I fixed it by welding a metal strip between the links stopping it from separating. After that I have been able to use the brakes for steering anytime when needed and as mine is a loader, that is most of the time when loading trucks. In 10,000 hours I have only replaced the disks once due to the wear pattern in ball channels. The friction disks although quite hard showed very little wear, although I still replaced them. If the brakes are up to spec, then I see no reason to shy away from using them whenever tight turns are needed. I agree about using the brakes for inching off a trailer etc. There was a valve available to stop the knockout valves from disengaging the tracks when braking and you may be able to find one from a wreck or Case specialist. On the 455C the park brake is very easy to use when you need to brake both tracks without disengaging the trans., not sure if this is easy to do on the earlier models. I have run mine in and out of the back of a tipper for nearly 30 years like this. One other thing, if the pedal is really hard on the side that does not work, it is most likely something is seized. I would start at the pedal and work my way back. loosen the master cylinder and see if the pedal moves. If it does, undo the hydraulic pipe coming from the master cyl, and see if the pedal moves further. If it does the problem is in the brake area, if not the master cyl is seized. Good luck.
Great information on the brakes I plan on looking into mine since the seller said the left side leaks I have found the number for the rebuild kit so plan on rebuilding both master cylinders.