621b case loader,,runs but will not release parking brake,,,no power to rocker parking brake switch,,all fuses are good,,, need some help please!
2000 621b rubber tire case loader,,red light with buzzer on and green light the would show everything is normal are off, ,they come on when starting but the go off imidiately are engine is running and red light with buzzer come on
The park brake on the 621B was a lever and cable. So the machine doesn't move? Does it move in 3rd and 4th gears? Does it move in 1st or second? Is the low brake pressure light on?
Just so happens I got a call today to check out no first and second , has third and fourth, and brake pressure light is on, 621b . Is there a separate brake pressure pump and what are the pressure specs. Are there any accumulators in the brake system. Thanks
When there is low brake pressure the transmission controller cuts out 1st and second. You need to check the brake pressure. As a temp fix you can bypass the relay under the dash. There is brake accumulators, and if those are bad, it will recover slowly from a brake application. I will find you some pressure specs.
Brake pressure switch is normally closed. Opens at 1250psi. Wire 31L should have 9volts (gets power from instrument cluster) Typically what I have seen is a bad pump (its just a crappy gear pump), but it could be other things also. The brake pump feeds the pressure reducing valve which feed the ride control, pilot circuits, and quick attach (if equipped). So, if your quick attach cylinder seals are bad, it can cause your issues. I would start by checking your brake pressures, and flow testing the pump. Brake relief pressure 2700 to 3000psi accumulator cut in pressure 1400-1500psi accumulator cut out pressure 2500-2600psi brake pump output 4.4gpm at 2500psi at 2200rpm.
Either it's not a 621B, or are you confusing the clutch cut-out switch with a park brake switch? Is it possible the park brake is set? Or, the lever isn't down all the way keeping the trans from engaging?? Or, the switch (I'm not sure where it's at) that controls the idiot light for the park brake has failed? Lots of possibilities.
Gary, thanks for the help. It should be in a few days and will let you know the outcome.