Bobcat 753 Lift only works with Auxiliary hydraulics engaged

[StarrTech]

Hello,

I have an old Bobcat 753 that had a stuck pedal. I took the control valve out, unstuck the spool valve, rebuilt it, and now the machine works great, except the lift only works with the Auxiliary hydraulics turned on, and the switch engaged to the right or to the left. The tilt only works with the aux not switched on left/right. Lift down works best with the aux not switched on left/right.

I already check the two auxiliary solenoids and spools, they both engage and i can hear the valve move. I don't see any obvious circuitry issues in the aux line.

I resealed the lift pressure relief valve too, as it had a broken seal.

Any tips for diagnosing/troubleshooting would be very welcome.


Thanks so much guys

 

[Welder Dave]

Maybe the mods. can move this to the skid steer forum. Likely to get more response there.

 

[BobCatBob]

Did you check before and after pictures of the hydraulic lines? I rebuilt mine (753 C, Melroe) and was worried about crossing lines (which isn’t likely as they’re a lot of hard lines, but still played it safe by labeling everything). Also, when put the spools back in, possibility of switching them? Just a guess, but likely something got swapped.

Do you have pics?

Bob

 

[BobCatBob]

Here’s a few pics….

 

[StarrTech]

Maybe the mods. can move this to the skid steer forum. Likely to get more response there.

Yeah I see now that this is in the totally wrong forum.

 

[StarrTech]

Did you check before and after pictures of the hydraulic lines? I rebuilt mine (753 C, Melroe) and was worried about crossing lines (which isn’t likely as they’re a lot of hard lines, but still played it safe by labeling everything). Also, when put the spools back in, possibility of switching them? Just a guess, but likely something got swapped.

Do you have pics?

Bob

I think it's got to be something internal to the valve but I don't know what it would be. I did take pictures before and nothing seems to be crossed. I didn't switch the spools or anything. I'm pretty stumped though

 

[2105]

Hi StarrTech, did you find a solution to this problem ? I have the same problem with an old mustang 2105