parking brake

[keeno]

Good evening all. New member from Ontario Canada here. I am a Kubota tech branching out to other models. I'm looking for assistance with a John Deere 310SL ser#242937, unit has 4100hrs on it. The parking brake began kicking itself on a few weeks ago, never stopping the machine completely, just causing a shudder. Stop , set brake and release, it could be fine for hours. First thing, checked fluid level, felt is needed service and was a bit low, so did the service with Deere OE parts and fluid. Unit was fine for 2 weeks, no issues. Today, got the call that the brake would not release, just flashes. No codes. Fluid fine. Swapped 7 and 8 solenoids as that was the only thing I could find consistently as the failure, no change. Now, my question, Does anyone have the diagram or schematic for this as i need to see the system to understand it. Any help would be great as I have nothing to go on here. Thanks in advance
Cheers

 

[JL Sargent]

The parking brake is spring applied and hydraulically released on these machines. Hopefully our resident JD tech "MG" will see this and have some specific things you can check to sort out the problem.

 

[mg2361]

Welcome to HEF keeno! Please post the full serial number. According to the number you posted it is a 310SK??

Did you happen to check the ohms of the solenoids when you made the swap? First thing to do at this point is to warm up the transmission, put a gauge (500 psi) in the park brake (remove the pressure switch on top of the Park Brake and place the gauge there). Check the pressure (park brake off) at idle (real important) and 1500 rpm (spec is 250-290 psi at 1500 rpm). Then post the results.

When you go into the monitor menu and check codes anything in stored? Also make sure there is no damage to the park brake pressure switch while it is out (check for wiring damage as well).

 

[keeno]

Good morning mg22361, and thanks for the response. Customer has 2 machines at this site, I may have mixed up the serial #s. The other serial # is 247912. I did not ohm the solenoids. I did not have gauge with me but will today. Is the reading taken at the differential? I have not worked on this system before so please forgive my ignorance. Without having the electrical map, seeing the trans mounted solenoid is only 2 wires, I am thinking the differential solenoid / switch receives the signal first then once it releases it releases the trans solenoid? Or am I way off base?

Thanks, Keeeno

 

[mg2361]

Both serial numbers are for "SK" machines, that correct?

Did you go into the monitor and look at active/stored codes? You can press menu button then scroll to diagnostics, then select. You can then look at codes (active/stored). Post them if any are found. To get into the service menu, key on, then press and hold the menu button for 5 seconds until "service menu" comes up. Then highlight and select diagnostics. Then from this menu you can clear codes. Run machine and release park brake to see what codes if any come back.

Is the reading taken at the differential?

Yes, the front of the rear axle is the park brake. on top of that just to the right of center is the park brake pressure switch. many times those or their wiring get damaged from ground debris getting up their. Make sure the pressure switch and the wiring are good. I have seen this pressure switch cause loss of as well as intermittent PB issues. Still plug a gauge into the port and measure the pressure as I mentioned above.

I am thinking the differential solenoid / switch receives the signal first then once it releases it releases the trans solenoid? Or am I way off base?

Check your conversation ("PM")

 

[chilco]

I’m having similar issues, I’m wondering if there is a specific resistance one could check on that pressure switch?