can't get air out

[scott1988]

I have a m5700 that I adapted a new holland tl270 loader to. Everything works fine except when I don't use tractor for a week. Hydraulics don't work at all until I remove supply line and let air out. I have no visible leaks. Once bled everything works great for a few days. Any ideas?

 

[wdchyd]

Suction leak on a suction hose, tube or shaft seal on the pump.......allowing the oil to drain back in the reservoir when not in use

Check all connections from the reservoir to the pump, if no obvious solution don't overlook shaft seal on pump

 

[scott1988]

Suction leak on a suction hose, tube or shaft seal on the pump.......allowing the oil to drain back in the reservoir when not in use

Check all connections from the reservoir to the pump, if no obvious solution don't overlook shaft seal on pump

Thanks I will take a look at those.

 

[Tx Jim]

Are you positive you have FEL valve correctly attached to tractor hyd's?

 

[scott1988]

I hooked it up the way a kubota tech told me to. It wouldn't work at all if it is hooked up wrong? Other than the functions being reversed.

 

[J_J]

You hyd system appears to be generating air, so check your suction line or replace and tighten clamps .

Look in your hyd tank after running and see if there are air bubbles in there.

 

[scott1988]

Can't visually see anything wrong with suction tube. Connections tight. Unless I'm looking at the wrong tube. It's about 1 inch diameter that goes from bottom of pump to side of transmission. There were lots of bubbles on dipstick. I will pull pumps shaft out to replace seals next I guess. Thanks for the replies.

 

[wdchyd]

Air entrainment is like drinking a thick shake with a small hole in the straw.....it makes bubbles in the oil

sometimes thick grease can be used to help locate the trouble area but it is not an exact science

 

[scott1988]

I have put new seals in with no change. Suction tube looks fine. I pressurized the tube while off to check for leaks and found nothing. What seemed strange was that when I took suction tube off the side of the transmission no fluid ran out. I had buckets under it thinking the fluid level would be above the tube. Dipstick reads full. If no fliud above suction tube, wouldnt it always drain back to tank creating air pocket? If I drive tractor while turning fully side to side it eventually bleeds the air out enough so the loader valve works but im afraid I will burn pump up since there is no fluid reaching it for approximately 2 minutes.
Thanks for replies. I guess the next step is to take it in and pay the big bucks...

 

[J_J]

Do you have a sump filter, and if so, check it out for sludge.

If a hyd component had an air leak, on the pressure side, it would also show a hyd leak.

If you take your pump hose going to the loader and place it in a bucket and start the tractor and run for a few seconds, you will verify if the pump is pumping.

If it does not pump fluid at start up, then I suggest your sump filter needs cleaning or replacement.

If you have air in the fluid, then you probably have a suction leak.