Peljob second hydraulic pump problem?

[Hankstains]

Hi guys and gals, firstly a happy new year to one and all.

Got a little problem which someone might be able to help with.

I have a peljob eb 25.4 which works great except for the dipper and right track.

A weird one this, it digs and does everything fine -mostly- during normal use. however if I try and push down on the dipper to lift the front of the digger off the floor it moves down lifts the digger about 4 inches then nothing, if i open the bucket it starts to fly up, stop using the bucket and it stops again. It is the same with the right track, on its own it moves very slowly with anything else working it moves great.
I know these machines have three pumps (see picture) Is it a knackered pump, or is it just as simple as not enough hydraulic fluid or a blocked filter??
I think when using another tool, pressure is passed from a good pump through the knackered one...maybe
Any help greatly appreciated.pumps schematic.JPG

cheers again

Hank

[Muz]

Its actually just one pump, which varies the out put according to demand. There are three high pressure feeds into the valve block. It sounds as though you have a stuck valve on one of the services, but more commonly checking the simple stuff first it could just as easily be something like a breaker pedal stuck 'on' or partially on, stealing oil flow from the other services, check that first and make sure its centered properly

[Hankstains]

Thanks Muz, will give that a look tomorrow, deffo makes sense given the schematic. is it worth connecting a breaker or something to the line to see what happens or just play with the pedal?

given how powerful the other services are, it does seem a bit weird.

thanks for the input.