Entec 30DH Hydraulic problem

[bolla]

Hi I have an Entec 30dh similar to Timberwolf 150 chipper

My Hydraulic pump is bolted to the engine not belt driven

The rollers seemed to be turning slower then usual but would some times speed up after being used for 15 minutes or so.

While using the chipper this morning rollers going slow then hydraulic oil started coming out of the filter housing in spurts, the oil level was showing high.

I switched off and even an hour or so later the oil level was still showing high.

I took the motors off that turn the rollers and everything seemed ok, started engine and splines would turn, put back together and chipped for a little bit after 5 minutes hydraulic oil spurting out from filter housing again and rollers a bit juddery. Switched off 

When i got I unbolted the pump to see if anything was obviously broken but not sure what i am looking at, did notice the hydraulic fluid level had dropped.

any ideas whats wrong

Thanks

[D.G.F.S.]

This might be a bit obvious but worth a try. Change the in tank hydraulic oil filter I’m not great with hydraulics big it may well be a blocked oil filter causing an increase in oil pressure then coming out of a relieve valve. When the engine is cold is the oil between the minimum and maximum levels? And have you changed or topped up the hydraulic oil recently?

[Jase hutch]

Drawing in air on the suction side somewhere between the pump and the tank  ?

[bolla]

I had some one look at the chipper and they replaced the hydraulic pump 

Has been working ok on small jobs

After a lot of chipping yesterday I noticed hydraulic fluid had leaked out of the seal between the filter housing and the tank (same place it leaked before but not as bad)

I was not feeding the machine myself as i was climbing but did hear the chipper anti stress kicking in and also a few bits jamming between the rollers sometimes getting stuck for a few minutes with machine running.

If the rollers jam up as a knuckle has got stuck could the hydraulic fluid get pumped past the rollers back to the tank causing to much pressure in the tank and the seal to leak?

Also is there a breather on the hydraulic tank

Any ideas why i get either too much fluid or pressure back in the tank causing the seal to leak

Thanks