Chipper hydraulic problem,looking for help.

[DonT]

I had to replace the hyrdraulic tank on my chipper.After replacing the tank and changing the filter.I fired it up and let it run real slow to work any air that might be in the system out.After running at operating speed for a couple of minutes I noticed foamy,milky fluid coming from the vent,and pressure was building in the tank.I shut it down and opened the filler cap and more foamy oil pushed out.It is -6 degrees celcius here,and i filled the tank to the full line on the gauge,would the fluid expand that much when warmed?Any other ideas to what might be happening?  Thanks DonT

[Gary_C]

Ya, you have an air lock between the pump and the relief valve. You need to crack a fitting open to allow the air lock to escape or back off the relief valve till it pushes the air out. It's like you cant get the pump to prime and it's pushing hydraulic fluid around and mixing with the air.

If that doesn't work, turn it on and crack a fitting but be careful as you can get a bath real quick and that hydraulic fluid is not easy on your skin and in your eyes.

[Coon]

Gary is right.  Make DanG sure that when you crack the fittings loose that you let the air off slowly or you'll need to bathe in floor dry then the shower. ;)  I have had issues like this in the past and the only way we got it to prime the pump was to leave the fitting disconnected and run the pump until you had a steady stream of oil coming out. We just pointed the hose in a five gallon oil bucket but through the pouring spout in the lid as not to make too much of a mess.

[vtlogger1973]

If there is a loose fitting between the resevoir andf pump, the pump will draw air and fluid at the same time, and could cause foaming.  Possibility?

[vtlogger1973]

Or maybe there is a pin hole in the suction line or the filter gasket did not seal properly and is allowing air into the system before the pump, which could cause foaming as well.