Hello, I have a 416C that has had a series of brake problems. The brakes recently wore out to the point the piston was over extending and brake oil was entering the dif. There was substantial debris from the worn discs, which was cleaned out, new discs and plates and a reman master cylinder were installed and the machine put back together. The manual specifies MTO in the dif and Hydo in the brake reservoir, which we did. Left the shop and brakes started to stiffen up on one side while the machine was running to the point where it eventually locked up completely. This was particularly common when the machine was cold. Went back to the shop, and after consulting with a senior tech advised to put TDO in dif with additive because of the new pad construction and it is a lighter weight oil. So, oils were switched out TDO with additive was put in and the brakes started locking up even worse than before. Brakes will come on gradual and get harder, the pedals will push to the top and machine will lock up. Everyone is at a loss as to why this is happening. Anyone have any advice? Thanks
If you open the bleeder do they release? If it has a bleeder? Going by same problem in an auto so may be a bad guess. Joe H
I dont recall having any problems like this after I replaced the brakes on my 416C (I've done it 2x now). I doubt that the oil has anything to do with your problem. Back in the day Cat recommended MTO for the diff, and also sold you an additive to put in there as well. I seem to recall that, at some point in the Cat backhoe production, Cat upgraded the brake linings to a Kevlar based material and at the same time started selling TDO which already has the additive in the oil (don't need to add it separately like with MTO). The whole issue with the additive is regarding brake chatter. Without the additive the brakes make a nasty howling/chatter noise (common with ZF rear diff, wet brakes)when they are applied. The absence of said additive shouldn't have any effects such as you describe. If I were you, I would be looking at the brake actuation system. Did you bleed the brakes lines? I know it sounds stupid but many problems, and wasted time & money, stem from overlooking the simple things. Next I would suspect the master cylinder.
Like the pistons not returning far enough for some reason?? Later Bob
ive worked for cat for 8yrs, done several differ brake jobs on the 416 s, never had one to start getting hard an locking one side down, dout what brand of oil ur putting in it has anything to do with it locking down, but I do suggest putting 2 bottles of the brake additive in the rear end to remove the chatter issues, cat say to add one bottle an run it for 50 hrs an if it still chatter then add another one, needless to say just put 2 bottles in from get go. there not expensive, but if ur positive you installed the piston seals an discs an plates correctly an feel good aout it, if the other side works fine an realease ok, see if ya can change out master cylinders from side to side an see if problem moves to other side
Yeah, we cracked the bleeder and the brakes released right away. Turned out to be a nasty combination of a worn spider gear (2 pinions almost seized) and a bad master cylinder. What threw us off the master cylinder was I was brand new, however it turned out to be bad. Not allowing the futile to return to the reservoir once it heated up. The worn pinions cause the plates and pads to rub and generate heat, causing the fluid to expand and push back into the master cylinder. Not an easy or cheap fix. Thanks everyone for your feedback.