JCB 426 loading shovel hydraulic issue

[Jack Russell]

Evening,

I have an issue with the hydraulics on our 426. It’s been doing it for a while now but never seem to get a chance to have a look. When you operate a service such as crowd back/steer full lock/3rd service, once they get to end of travel i assume the pressure relief goes off. The weird bit is it keeps making noise as though it is blowing off when you let go of the wheel/lever/button. It only stops when you operate something else. Sometimes it does it with out taking something to the end of its travel. Hopefully this makes sense and someone can give a bit of guidance on what i need to look at.

Cheers
Will

 

[Jack Russell]

A suggestion is that it may not be the pressure relief valve, but it could be the load sensing valve that’s at fault.

@ACEngineering

 

[cosmagedon]

Yes, as it's doing it on various functions it could be the compensator on the pump or the swash plate inside sticking, apparently that's a known issue to look out for.

 

[ACEngineering]

Evening,

I have an issue with the hydraulics on our 426. It’s been doing it for a while now but never seem to get a chance to have a look. When you operate a service such as crowd back/steer full lock/3rd service, once they get to end of travel i assume the pressure relief goes off. The weird bit is it keeps making noise as though it is blowing off when you let go of the wheel/lever/button. It only stops when you operate something else. Sometimes it does it with out taking something to the end of its travel. Hopefully this makes sense and someone can give a bit of guidance on what i need to look at.

Cheers
Will

Do you mean a spool sticking so its constant pumping?

 

[Jack Russell]

It can do it on any hydraulic function. Usually when you reach the limit of travel ie crowd right back or steering full lock. But it can do it as soon as you steer/lift/crowd etc. It’s a 10000hr machine.