When the control rod for the Lift-All is in neutral the loader slowly raises up.

It was acting worse, but when I took the pump out of the reservoir the cap for the pressure relief valve was rolling around loose in the bottom of the reservoir.

That fixed a lot of the problems, but the control has to be 2" forward of it usual position to keep the loader from lifting.

I'm not so excited to take the pump all apart without some idea of what to look for. Especially since the weathermen are all excited about a big snow storm we are supposed to get Tuesday night.

Greg

Are you sure you have the outer control lever properly indexed and tightened. You don't say if this was a problem before you took it apart. Far as that cap over the relief valve, I always bend the lever (it is mallable )carefully so the cap can't sneak out of there. And then I do a little grinding or fileing to get a good lock in the raise position. One easy way to check to see if the relief valve is a problem with poor performance is to just lock the lever back and try to lift your load, if lever stays and lift is slow or not at all it is the gears and body that is the problem. If it kicks the lever off it is the relief valve opening up and that cap trips the lever . I don't have a good answer for your rod being out wack if it worked all right before. Several different rods for those tractors and even the light bar may be out of position.

It could have a bent internal part, Is the rod pretty straight. It should be almost straight.
In the mean time I would make a temporary offset bracket from some 1/4" strap and use that to control the lift. or bolt a 1/4" plate with two holes 2" apart to the top of the control arm, making the rod 2" longer in effect. Jim

The operating rod is still straight and the lever only has 4 lugs, so indexing should be good. The internal parts look pretty robust and nothing looked bent or too worn. Making a 2" extension seems like a good work around for the short term.

The pump locks in the raise position and lifts like normal. It was getting dark so I just checked it sitting in the shed and didn't run it all the way up. The left cylinder leaks a little and at times squits oil out at full extension.

The previous problem was that when I pushed the rod foward to lower the bucket the rod would bounce back and the and the loader would stop unless I held the rod down. In addition the loader would raise when the rod was on the stop and it did not have much power. I'll give it a little better try out today.

I have an older pump. It has been updated to the 750 psi spec at some point. My parts book only shows the later version. What does the 'hold up ball lift pin' do ? I think I have the earler version of the 'differential check valve lift pin' ( externally, both pins are the same size). What does it do ? The differential check valve, valve ball, and spring (#s 70, 71, 72) are only listed for SN 391364 and up. How did the earlier version work ?

Thanks

Greg

The differential lift ball, pin and spring has a couple of purposes. This pump was designed to have a delayed drop where as you first pushed lever forward far enough to release the first check ball which would be the outlets that are hooked together on both side of pump and then to say lower the rear section of a cultivator you pushed lever farther to release second check ball that is connected to the single outlet. Well, often times the first ball opened hard so you had to push pretty hard and in so doing you inadverdently pushed the second check valve also so all dropped at same time. By using the differential check valve it required much less force on lever to release that first check giving you better control of second check ball. What I liked the differential check valve for , and I did install them in some pumps that did not have them, was with a heavy load on a loader for instance, you have much better control for a lowering the loader. If you pump will latch ok like you say, next thing to determine is if on the lowering cycle you are actually opening those check ball with the lever or is the spring inside opening them by itself, in other words, is you inner lever in the slot of that cam mechanism properly. If it works, just change your stops on rod to get it where you want it .Neutral, raise, and lower.

Thanks for the explanation.

I believe the inner control arm is in the slot of the cam and piston valve lever. It took several tries to get it. When the outer arm only had a little free play I figured that it was there. It also seemed to work the cam lever in both directions on the bench.

Can the differential check valve be added to older (sn 23854 ) tractors ? Lowering the loader just a little or slowly can be very tricky.

Greg

Well, the control rod does latch back and for a few cycles the pressure relief valve did trip the lever back to neutral, but now it is not going back. It does not make any difference if the bucket is full or not.

Also when I push the rod ahead to lower the bucket the rod will pop back and the bucket stops. This seems worse at higher rpm.

Any ideas about what to look for when I take it apart again would be much appreciated. This time I'll take the pump off the back plate and have a look at all the pins, balls, springs, etc.

Greg

It would be good to know the free length of the springs, etc. Any other specs would be helpful too. Anyone know those ?

Thanks

Greg