John Deere 482C spews oil out of the reverser dipstick while turning on parkbrake

[Hardline]

I have one that has stumped me. I have a 482C that when you turn on the park brake it allows the spring to appy pressure and set the park brake. This spring is pushing the fluid back into the dipstick of the reverser and the oil will blow the dipstick out. The vent on the dipstick of the reverser is going to a fitting on top of the reverser housing. The vent is clear. Any ideas as to why this would start doing this? The operator says he unbolted the park brake canistor to replace because the rod seal was leaking. But a replacement was not available and the machine started doing this after reassembly. Thanks JJ

[willie59]

I'm not sure what's causing your problem, but looking at the parts diagram for that machine, looks like parking brakes is controlled by a solenoid operated three way valve. It appears to get pressure to overcome spring to release parking brake from reverser pressure circuit. When you flip switch to set parking brake, solenoid valve can't let trapped fluid go back into reverser pressure circuit, so it looks like it sends this oil back to dipstick to return to reservoir.

Question that I would have; is the vent on tranny housing plugged causing reservoir to become pressurized and blowing dipstick out when you set parking brake?

[Hardline]

I'm not sure what's causing your problem, but looking at the parts diagram for that machine, looks like parking brakes is controlled by a solenoid operated three way valve. It appears to get pressure to overcome spring to release parking brake from reverser pressure circuit. When you flip switch to set parking brake, solenoid valve can't let trapped fluid go back into reverser pressure circuit, so it looks like it sends this oil back to dipstick to return to reservoir.

Question that I would have; is the vent on tranny housing plugged causing reservoir to become pressurized and blowing dipstick out when you set parking brake?

I have checked the vent. There is a hose that goes from the dipstick tube over to the top of the reverser housing. It is clear as I can blow air through it. What does question me is that when you put the dipstick in and seal it up the case is not externally vented. So the dipstick tube is vented to the top of the housing but not externally and it does build up pressure.

One thing Im not sure of though. Seems like the stroke on the park brake canister is quite a bit and that would use a lot of oil to fill the canister. To where if it were adjusted up maybe it would have less oil that the spring is pushing back.

I do have the factory procedure to set the parking brake but the machine is 100 miles away. Might just have to run out there anyway. Just would like to have a good hunch as to what is going on before another trip out there.

[willie59]

I've never ran into this problem so I don't know solution. Just thinking though, I would wager the adjustment spec doesn't let brake release chamber travel all that far, I suppose it's possible that excessive chamber travel could cause your problem.

[moeinfo13]

Hey, I know this is an old post but I am working on a john deere 482c with the exact same problem that you had. Did you ever find out the problem?

[twr]

we have seen this in backhoes where the brake is out of adjustment , so its using and dumping more oil,also we've added a 90% turn to the return tube to force it down