I have a 544H that seems to only drive in 1st gear, forward and reverse. When I shift to 2ed gear it locks up like the parking brake has been applied. If I start the loader in 2ed from a stop, it will not move more than 6 inches then stop again as if the parking brake was applied. One of my guys held the pedal down and said that it "broke free" after about 5 feet of driving. The "FAULT MODE" then displayed on the dash but worked good until the machine was turned off. We have replaced the speed sensor that is on the front right side of the transmission behind the filter with no change. Any help would be helpful.
I have seen several of those style park brakes fail. Most would start leaking and burn up. They will also overheat if overfilled. Those ZF transmissions will throw a code if stalled, or left in gear without movement for very long. Pull the drain plug on the park brake and see if the oil is full of metal.
kjkoch, Thanks for the reply. The fluid was changed and looked good. Don't you think it would be more in the electrical part of the brakes? The parking brake works fine, just wont always release.
An electrical issue is highly possible too. You can tee in a gauge at the brake and watch it. I think its supposed to be around 250 psi to release it, I don't remember. We did have a shifter switch go bad occasionally too.
Thank you.
UPDATE - I was able to borrow a shifter selector from my neighbors 644H but did not fix the problem. Runs / drives great in 1st gear but parking brake locks up when shifted into 2ed, weather on the roll or from a start. Any other ideas??
I don't remember ever running across that problem. I think I would wire in a light at the park brake solenoid, and a gauge on the park brake itself, and run it to see what is actually dropping out.