50 Hr SVC can not get hydraulic pump to prime

RJFEJF · Jan 16, 2013

Thanks I'll give it a shot in the morning.

J_J · Jan 17, 2013

How cold is it where you live.

Try warming the fluid if necessary. Might help.

RJFEJF · Jan 17, 2013

It is about 48F in the garage. I did put a magnetic block heater on the case for about an hour. Tryed the air, didn't work. Maybe I caused the problem. Would it make a difference in getting prime if I had left my rear blade attached to the 3pt with the blade resting on the garage floor? If it does make a difference, should I unhook the rear blade and see if the lift arms drop? If this does not make a difference it looks like I may have to get into the were this return line meets the supply line between the filter canister and pump. This will still be about 4 inches below the pump and after the filter assy. The filter hoses on both sides of the filter weep oil when cracked.

xring100 · Jan 17, 2013

is it possible to crack the fitting right at the entrance of the pump in the inlet side and try your air trick. this creates a leak path for the air which should then force the oil up the tube towards the pump. as soon as you see oil close the fitting with the tractor running

Dave.

SSdoxie · Jan 17, 2013

Find it hard to understand why air didn't work, it should push oil up through the pump without the pump turning. Where is the air breather for the transmission/reservoir? Is it seperate from the fill cap? If so put the fill cap on, take the breather out and put air through there. If the breather is seperate from the the filler cap all your air pressure was going out the cap.
It won't hurt anything to over fill the tank some to help get the oil up there. Once it is primed you can always drain or suck some back out.

I sincerely hope the 2 hrs. running time you have put on this with dry pump hasn't worn the pump to point it can't prime and pump.

xring100 · Jan 17, 2013

Hydraulic pumps don't pump air all that well they prefer incompressible fluids like hydraulic oil. you have air trapped in the line in front of the pump, pressurizing the reservoir will only cause the fluid to compress the air and hit resistance. You are also pressurizing all the return feeds which are trying push the fluid as well but in the wrong direction. Cracking the pipe fitting on the inlet to the pump will then allow this trapped slug of air to escape and force the fluid up the pipe to the pump. as soon as you can get fluid to the pump it should prime immediately and your problems will be solved

RJFEJF · Jan 17, 2013

Got it xring100, provide an evacuation point for the trapped air to escape right at the pump inlet ! I believe I may have been over thinking this one. Hey, I am a newbie to tractors. I thank you for the clear explanation. Will give it a try tomarrow.

xring100 · Jan 18, 2013

RJFEJF said:
Got it xring100, provide an evacuation point for the trapped air to escape right at the pump inlet ! I believe I may have been over thinking this one. Hey, I am a newbie to tractors. I thank you for the clear explanation. Will give it a try tomarrow.

Yep exactly, I really Hope it helps. I've never had a problem getting my pump to re-prime. If it does not work call the dealer and talk to a tech and ask them what kind of voodoo they do.

Dave

J_J · Jan 18, 2013

RJFEJF,

Is there any reason that you can not add a tee at the input to the pump and filling the tee with fluid to flood the pump input gears. You can keep adding fluid through the tee until the pump fills the line to the tank.

That is assuming that all things are connected correctly.

RJFEJF · Jan 18, 2013

I may have to cut in the supply hose as you say, If cracking open the fitting to let the air escape at the base of the pump does not work. I am going to give it a try after I finish working today. Question, my leaving the rear blade on the 3pt in the down position during the service have any effect on the pumps ability to prime? Thanks.