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Problem with Lull 844c brake/transmission

g3e3r3d

Member
Joined
Jun 1, 2010
Messages
8
Location
Washington
I've got a Lull 844c-42 with a problem. I'll be driving it along fine and all of a sudden it will 'slip' out of gear. At this point I can rev the engine all I want and no movement. I can put it in neutral then reverse and still no movement. Then I can pull the hydraulic emergency/parking brake valve on then off and then it will move again. Sometimes it takes several times of pulling the parking brake on/off before it will work.

Someone told me there is a solenoid or valve connected to the brake hydraulic line that disengages the transmission when the parking brake is pulled. Is this true? I have a hard time trying to trace the hydraulic lines, anyone know how I can find the part number to order a new one and where on the machine this is located?

Suggestions greatly appreciated.
Thanks!
 

icestationzebra

Senior Member
Joined
Jun 21, 2009
Messages
366
Location
WI
Unfortunately somewhere with all my moves I have lost my schematic diagrams. But I'm pretty sure all of the interlocks are done electronically. My guess is that you have a failing relay, or possibly a bad connector. The next time it fails you might try wiggling the relays, or installing a new one. There are some LEDs on the circuit board that you can use for diagnosis.

ISZ
 

g3e3r3d

Member
Joined
Jun 1, 2010
Messages
8
Location
Washington
Thank you ISZ,
I will give your suggestions a try. Unfortunately I don't have access to the machine right now as it is on its way up to Alaska, but I'll try to order the right relay and be ready with it when it arrives up there. Any suggestions on the best place to get parts (IE most helpful in holding the hand of a contractor trying to work on their own equipment)?
 
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