Hydraulics erratic after rebuild

Skeeter102 · Jun 30, 2015

I pulled the top cover and replaced the piston with the naa piston. I also replaced the cam follower pin, friction disk, and safety valve. I used zane's jig and I think I got everything in spec. Now in position control (lever up) as soon as I start to move the quadrant lever down, the lift starts to fall immediately. In draft control, the hydraulics will not raise at all. So, I adjusted the plate on the quadrant back some. The lift now seems to work in draft control but position control still does not seem to work right. Once you move the quadrant lever a 1/4 of the way down, the lift drops.

There are no leaks anywhere when looking through the top cover.

What did I do wrong?

ZANE · Jun 30, 2015

You didn't call me!

Zane

Skeeter102 · Jun 30, 2015

(quoted from post at 16:13:49 06/30/15) You didn't call me!

Zane

I left the instructions(with your phone number) on the bench at work. I cussed a little when I realized that. I definitely needed to call you.

Skeeter102 · Jul 2, 2015

Just wanted to add to this. Below are some pictures of the top cover. Does everything look installed correctly? I had to pull the linkages apart to install the new cam follower pin. I think I put it all back right but just wanted to make sure.

I plan on pulling the cover back off and rechecking the adjustments with the jig and the steps outlined in the FO-4 manual and operators manual.

After reading those, I think I may have the draft control spring too tight. I cannot move it by hand as the manual suggests.

Any thoughts would be helpful.

Zane, I plan on giving you a call next time I am by the tractor. I don't think I'll get to it until week after next. Going on a much needed vacation next week.

JMOR · Jul 2, 2015

Big control spring too tight isn't really important unless you plan on using a draft implement as all that will result in is requiring excess top link pressure (heavy draft) in order to cause the plow to lift. In your pictures, you have the POSN/DRAFT lever set to DRAFT, yet the linkage shows POSITION is in control of the control arm....clearly wrong. Why? Possibly bent draft control link or badly mis-adjusted constant draft control spring &/or position control spring.

Skeeter102 · Jul 2, 2015

(quoted from post at 15:45:11 07/02/15) Big control spring too tight isn't really important unless you plan on using a draft implement as all that will result in is requiring excess top link pressure (heavy draft) in order to cause the plow to lift. In your pictures, you have the POSN/DRAFT lever set to DRAFT, yet the linkage shows POSITION is in control of the control arm....clearly wrong. Why? Possibly bent draft control link or badly mis-adjusted constant draft control spring &/or position control spring.

That explains why if I held down pressure on the draft control lever, the lift would operate.

I use a 6' box blade on this tractor and typically run it in draft control.

I will check the springs. Can I measure them as indicated in the manual? Or, is the wear sufficient enough to cause these measurements to not be correct?

I think after I do that, I can use the jig to line everything up again.

Skeeter102 · Jul 20, 2015

Well I used the jig and is well, save for one minor issue.

Now when I have the tractor at idle or shut it off the lift drops.

My tractor has live hydraulics installed. Is it possible that the check valve I have I installed at the test port is clogged with some debris? That's the only thing I can think of that could cause this issue.

Hydraulics erratic after rebuild

Skeeter102

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ZANE

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Skeeter102

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Skeeter102

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JMOR

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