EC25 engine cuts out when hydraulic fluid gets hot?

[Richard Dye]

I have an EC25 Volvo and I can start it easily when it is cold and it works perfectly but after about ten minutes, when the hydraulic fluid gets hot, the engine stalls and will not restart, it is also very hard to turn over on the key. Once it has cooled down, it will work again for 10 minutes?
I have put on a new filter and there is plenty of hydraulic fluid in it. The hydraulic intercooler doesn`t get any where near as hot as the pump on the engine. If I disconnect the hydraulics to the pump... (aside from getting covered in hydraulic oil) the engine will start.
Any ideas please?

[Muz]

If I remember correctly ,.. The machine is fitted with a variable displacement pump, which has a 'no load' valve fitted to it to make the swash plate return to zero every time the machine is switched off in order to not load the starter motor should a service be opened during start procedure, it sounds like that valve is stuck. can you take a picture of the pump ?

[Mick-the-fitter]

I have an EC25 Volvo and I can start it easily when it is cold and it works perfectly but after about ten minutes, when the hydraulic fluid gets hot, the engine stalls and will not restart, it is also very hard to turn over on the key. Once it has cooled down, it will work again for 10 minutes?
I have put on a new filter and there is plenty of hydraulic fluid in it. The hydraulic intercooler doesn`t get any where near as hot as the pump on the engine. If I disconnect the hydraulics to the pump... (aside from getting covered in hydraulic oil) the engine will start.
Any ideas please?

Hi Richard,

Just check to see that the hammer pedal is in a neutral position, and all functions are operating correctly!

Mick