8630 hydraulic issues

[Bill Marcusky]

Have an 8630 that will every thing works fine for about 20 mins then the hydraulics slow up and mostly stop working. Only steering and brakes still work at this point. Both are very weak after it warms up. No other hydraulics work at all once warm. All 3 screens just cleaned and new oil put in. Replaced trans pump suction tube o rings and rubber hose section. Same problem. Tractor will always drive around even when hydraulics quit. I'm thinking the trans pump is getting weak and once oil is warm the pump isn't making enough flow to supply both the main hyd pump and transmission clutches at the same time. Planning on pulling the trans pump tomorrow for inspection unless anyone has another suggestion

 

[wore out]

Have an 8630 that will every thing works fine for about 20 mins then the hydraulics slow up and mostly stop working. Only steering and brakes still work at this point. Both are very weak after it warms up. No other hydraulics work at all once warm. All 3 screens just cleaned and new oil put in. Replaced trans pump suction tube o rings and rubber hose section. Same problem. Tractor will always drive around even when hydraulics quit. I'm thinking the trans pump is getting weak and once oil is warm the pump isn't making enough flow to supply both the main hyd pump and transmission clutches at the same time. Planning on pulling the trans pump tomorrow for inspection unless anyone has another suggestion

You REALLY need to obtain an OEM Tech Manual and work your way through the troubleshooting procedures before tearing randomly tearing stuff apart.

The hydraulic system recycles function return oil back to the hydraulic pump and very little excess flow from the transmission pump is needed to add to the charge flow to the hydraulic pump to keep the hydraulics working in normal operation.

Does it make any difference if the quad is in hi or lo, or if the PTO is engaged or in brake mode?