MF 1431 Air in the Hydraulics.

[USMC2145]

I replaced the hydraulic filter on my tractor and now I have air in the hydraulic system. I attempted to bleed the air per the owners manual but this failed to get the air out. I have tried with the FEL hoses disconnected and connected. Nothing works. I tried running the FEL up and down several times but nothing; same with the steering. The hydro still moves the tractor but I can hear the air in the system. Right now there is no FEL control or power steering.
Any and all help is appreciated.
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[JerryG]

Move the loader control to the limit, hold it there for a few seconds. Then move it to the limit in another direction and do the same thing. Do this until the air is out. It shouldn't take but a minute or two and you will be back in business.

 

[USMC2145]

Jerry:
Thanks for the tip. I tried this and it did not work. Any other suggestions?
Thanks again.

 

[JerryG]

If that didn't work , the air is getting in faster than you can bleed it. The air is still getting in. You may have not gotten the filter on right or the 0-ring from the old filter is still stuck to the housing under the new one. I would bet it is the O-ring.

 

[USMC2145]

Jerry:
I thought that to. I pulled the filter off and double checked it. It just seems like the amount of air that got in was alot. The fluid seemed to drain for a long time after the filter was removed. I had to add about 3 gallons to bring the level back up. I know; this is weird. Is there a different bleed point on this maybe higher up as the one that is shown in the manual is on the bottom of the tractor? I hate to have to bring it to the dealer for something that I should be able to do myself.
Thanks again.

 

[JerryG]

The hydraulic system is a self bleeding system with use. All the fluid dumps into a open sump. If you can't bleed it by working the loader and the three point, there is a air leak in the system somewhere. Just because you can't see a leak of fluid doesn't mean the there isn't a suction leak into the system. Check the suction tubing. I guess the on the MF 1431, the filter is attached to tubing? If it is, check all of the fittings on that tubing for tightness. You can have a suction leak and not have a fluid leak. Again, try running the loader up and down several times, because if all you did was change the oil and / or filter that is all that should be needed to bleed the system. Let me know how it works out.

 

[USMC2145]

Jerry:
I wish that I had a diagram of the hydraulic system to check the return lines for a possible leak. I can't get a service manual from the dealer as he states they are not available yet. I can't think of anything that I might have loosened that was not retightened. I will try and check everything associated with the hydraulics. It is definitely getting air from somewhere. The trick is just finding it.
Thanks again.
I will keep you posted as to what develops.

 

[JerryG]

I don't have a diagram for a 1431, but your suction line should start on the right side of the transmission as you are sitting in the seat. I think that it will be almost at the bottom of the housing and almost exactly under your seat. It may or may not then go to the hydraulic filter. From the filter it would go to the pump, that is mounted on the right side of the engine.

 

[JerryG]

Did you double check to see if the o-ring on the bottom of the old filter didn't stick to the filter housing? If it did, you will have two rubber rings and you can suck in air.

 

[USMC2145]

Jerry:
I pulled the filter off to double check(only one gasket) I filled it with fluid then put it back on (nothing). On the 1431 there is a large steel tube ~1" in O.D. that runs from the bottom of the rear housing and goes forward to the bottom of the pump then there are 2 lines that exit the top of the pump (1 flex high pressure and 1 steel) they both run behind the engine near the steering column and I can't see where they go from there. I figure one goes to the power steering and one goes to the other side and down to the filter. It's very hard to trace these lines because they tend to be routed where they are hard to see. There is also a block on the right side of the rear housing that has the block that the FEL lines connect to. I tried to figure which is the suction and which is the pressure side. If I figure that out it's just a matter of re tightening or checking everything.
Thanks.