Volvo l70c hot oil

[SMR]

Hi have a problem with an l70c heating the hyd oil. When the loader is idling the hydraulics are under load, whilst idling if you pull a lever and the loader starts to move the engine actually revs up like the load is coming off the engine. None of the spools are sticking. Are they a closed centre system and the pump isint unloading or do i have a problem with a return?

 

[Volvomad]

There can be other reasons but one of the pumps may have broken cradle bearings . It has happened me more than once . The brake charging circuit is the most likely problem though . Does it start loading the engine on start up ? There is also a switch to momentarly increase Q H pressure on the left side of the dash which could be jammed or faulty .

 

[SMR]

Thanks for your reply. It was the brake charging circuit because when I power that solenoid it unloads. Have powered it temporarily until we can bring it into the workshop to go through it. what usually goes the accumulator?

 

[Volvomad]

More likely electrical . There is an adjustable pressure switch on the brake accumulator block . The DIN plug gets corroded or it might be the switch it self .