T-Control Jumpin~Bean

[johnbron]

I have been changing fluids on the newly purchased (49) and I filled the tranny with diesel fuel to flush. I just drove it to the neighbors to churn up the diesel and while there he wanted to know how the hydraulics work so I lowered the tool bar up and down a couple times successfully and then all a sudden it started to jumping. The only position it doesn`t jump now is all the way down. I know there was recently a thread about this problem but I cant find it. What is normally the cause for this and is there a quick & easy fix?.

[johnbron]

Johnbron-

Did you also drain and refill the touch control reservoir? You may have air in the lines.

Nope, I haven`t messed with the touch control as far as draining, I have only drained and refilled the engine & tranny. I know there was a post about the same problem recently. Maybe it was on the ATIS board. Wish My memory would come back from vacation. I shall find it but just thought I would cut corners and ask. _Thanks_

[johnbron]

johnbron-

Does the "jumping" increase as the engine RPM's increase?

I had a Cub with this same symptom a while back. Bigdog suggested it could be oil leaking past the o-rings on the cylinder or a faulty relief valve.

It was the O-rings, and the problem was corrected after new replacements were installed.

I drove it home with it in the down position where it did not jump but when I raised it I believe it was jumping faster with RPMs increased. If anybody has the solution to fixing this I would appreciate hearing about it. I thought fer`shore I would have got a hands on experienced answer by now with this many Cub owners on board. Maybe somebody will answer Bigdogs request for a workshop T-control demonstration at Cubfest and the info will spread from B.Ds house across the world.

[Bigdog]

JB, I would suspect the relief valve sticking, but I'm no hydraulics expert. I'm more of an ex-spurt (drip under pressure).