Jubilee rear lift problem

[alby]

Hi, I've got a '53 Ford Jubilee with the original vane type hydraulic pump for the 3-point lift. I am having a problem with it settling & not lifting once the hyd. fluid is warm. It works fine when it's cold so I'm assuming it's probably wore. I was wondering if anybody has used "Lucas Hydraulic Oil Booster & Stop Leak" added to hyd. fluid? They claim it will boost pressure on worn pumps & I thought it might be worth a try as it's almost impossible to find a good used vein pump & I really don't want to spend $700-$800 on a piston pump conversion. Any thoughts on this would be appreciated.

 

[Dollar Bill]

The pump may be worn but you could also have a worn ram cylinder. Load the lift with your heaviest implement and pull the plug in photo to see how much it's leaking from the cylinder. A steady drip is OK, if it's pouring out, you've likely found the problem.

Also, what hydraulic oil do you have in it now and when was it last serviced?

 

[alby]

Thanks for the reply, I'll give that a try. I changed the hyd. fluid in the fall (old fluid was clean), put in Walmart's Super Tech Heavy Duty hyd./trans. fluid. This is supposed to meet the specs. for NAA tractors.

 

[Soundguy]

Do the leakdown test as specified. if it is a strong leak, that AND a worn pump means that when it gets hot, it's just too much to overcome.

the lift piston is easy to replace. hopefully the cyl is not scored past what a honing will do.

 

[alby]

Thanks for the added information. I haven't had a chance to try anything yet but as soon as we get a little better weather, will give it a try.

 

[alby]

Thank you "Soundguy" & "Dollar Bill" for the suggestions. The lift piston was leaking a lot of oil so I did take the lift cover plate off according to the instructions in the NAA shop manual. I installed a new piston with new o-ring & leather ring. The cylinder was in good shape & didn't find anything else wore, but I did put in a new cylinder safety valve. The valve (FDS353) was different on the ball end than the original but is supposed to be for NAA & Jubilee. I drained the fluid out & it was clean, cleaned bottom of center housing, put everything back together, turned back pressure valve (under acorn nut) back in, bled pump, have pressure at auxillary control on top but 3 pt. won't lift at all. Before I did all this, it lifted o.k. when cold. The only thing I can think of is the difference in the cylinder safety valve, but before I tear it apart again was hoping for some ideas (something I missed?). Thanks again for any help

 

[Dollar Bill]

Are you aware of the correct procedure for removing and replacing the lift cover in relation to the back pressure valve and the acorn nut? It is under the big acorn nut that is located on the right side of the lift housing. The nut must me removed and the large hollow stud must be turned at least two complete turn to the left (counterclockwise) so the back pressure valve will be clear of the internal lift components when the lift cover is removed. Do not turn the hollow stud too much or you will damage the back pressure valve and the unloading valve will not work if the back pressure valve is inoperative.

 

[alby]

Yes, I was aware of the procedure. I took it apart again to double check everything & it all looked o.k., so I took out the new cylinder safety valve (#FDS353)& compared it to the original one & realized that the spring on new one had way less resistance than the old one. I put the original back in & now everything works perfect. It's really frustrating when the new valve was listed as the proper one for Jubilees when obviously it's not. So after all this, it turned out to be just the piston, leather ring & o-ring (pretty cheap fix). Thanks again for the help.

 

[Dollar Bill]

Thanks for letting us know you solved the problem. I had it in my mind to advise replacing the original relief valve in my last response but old timers disease caused me to forget.

 

[Soundguy]

gotta love bad, new parts that jump in the mix.