Filter change, problem bleeding air out of pump

425trailer · May 7, 2004

Help! I've just changed my first hydraulic filter on my 425 and follow this with bleeding the pump as instructed. I had oil and air the first two attempts, but after this istead of running out of air I ran out of oil. Zilch, nothing. I briefly ran the engine with absolutly no response to the forward/reverse pedals. What now? I shoudn't have chosen a Friday night to do this the first time as now I won't get any help from Power Trac until next week. /forums/images/graemlins/frown.gif /forums/images/graemlins/frown.gif

Bob999 · May 7, 2004

Did you check the oil in the tank to ensure the proper level?

Did you fill the filter with oil prior to installing it? If you didn't it will take a lot of bleeding to get it filled.

Is the filter firmly installed with no air leaks? If not air will be sucked in because the filter is on the suction side.

Bottom line is you have to do the purge--turning the engine over with the bypass hose installed and returning directly into the oil tank until you get a clear stream with no air.

425trailer · May 7, 2004

Thanks for the reply. I filled the filter to the brim and turned it on tight. I will try it again tomorrow morning. Possibly I gave up on the bleeding to soon, I just wasn't comfortable with continuing to crank with no oil coming from the hose. /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif

davesisk · May 7, 2004

Just FYI...make sure that you have the spark plug wires disconnected so the engine can't possibly start accidentally. The gear pump that powers the cylinders is self-priming, but the hydrostatic drive pump will burn up in about 60 seconds if it's sucking air rather than oil. I'm sure you probably already know this, but I'd rather insult your intelligence than see you burn up a $1200 pump! /forums/images/graemlins/cool.gif

Take some breaks between cranking so the starter doesn't overheat. Filling the filter with oil is a very good thing to do.

Good luck,
Dave Sisk

425trailer · May 8, 2004

I've tightened the filter this morning and again attempted to bleed the pump. Better results this time, by the second 15 second interval I was getting mostly oil. However, after 8 pumping intervals of approximatly 15 seconds each I still get some spurts of air every 3 to 4 seconds. Is this still to much? What am I missing? Being this is a beautiful Saturday morning I am seeing just how much I need this machine.

toy · May 8, 2004

I have only had to change my filter once, I only have about 88 hrs on it . When I did change it I filled the filter up with oil waited a few minutes to let oil soak into filter then caped it off again put the filter back on and there was hardly any air come out of the hose, I hope the next time it goes that smooth. Hope yours works out ok.

425trailer · May 8, 2004

I am glad to report that I have been able to use the PT today. A few hours after my first attempt I again bled the pump. I was still getting a small amount of air. I suspect that when I first installed the new filter it didn't completly seal, causing air to be sucked in and through the entire drive system. After bleeding I drove a short while and let it set 15 minutes. The oil was now warm ( thinner) and I bled it again. Seems to work fine now. Next time should be much easier now that I understand how this is supposed to work, I really should have thought it through fully before I caused all this inconveniance /forums/images/graemlins/tongue.gif