Jubilee hydraulic help needed!

Lynn Patrick

Well-known Member
Decided today was a good day to try to figure out why no lift at all on the Jube 3 point. Checked the I&T FO-19, attached a hose to the pump primer hole & fired it up. Full flow instantly! Let it run several minutes, replaced plug & still no lift. I&T then had me pull the cover, which is now on my work bench. It then tells me how to repair each individual part, but not how to tell which part might be failing.
What's my next step?
Oh, & I love this FO-19 manual. Index sends you to #127 which starts out "first remove...as in para. #123". Go to #123, says "as in ...#121". Maybe I should have just started reading from the front!!!
At least I'm still having fun!
 
On many with that problem the unloader valve is sticking which will cause a problem like you having. As far as the I-T manuals yep you have to read and then reread them just to get to where you need to go on some things
 
If it is determined that the pump is operating right and supplying enough volume of oil under pressure to the hydraulic system then you may have a sticking unloading valve in the lift ram cylinder housing.

If the lift is jumping/bumping/hiccupping it is caused by the lift trying to hold the height constant with a leak internally of the hydraulic system. The leak must be fixed before these symptoms will go away. Common leaking places are the ram cylinder O ring/s, the pressure relief valve, the O ring on the unloading valve or a blown gasket under the ram cylinder to housing flange surfaces.
On the 53 and up Ford tractors there is a gadget named the unloading valve. It is hydraulically shifted by the movement of the control valve. The control valve does not actually move oil to the ram cylinder. The oil is directed to the ram cylinder by the position of the unloading valve. The Hundred series has the same valve in a slightly different form but performs the same function.
If and when the unloading valve stops moving then the lift won't lift until the problem that is causing this condition is fixed.
A faulty back pressure valve can cause the unloading valve to stick.
The unloading valve can stick on it's own.
The unloading valve has an O ring that can become worn until it will not allow the valve to move.
The pump could have lost it's prime too. The piston pump must be bled by opening the front head plug in the pump and running the engine slowly until all air bubbles are gone from the escaping oil. Stop the engine, replace the plug and start the engine again to see if that fixes the problem. It can! Someone said to replace the unloading valve oring with only the Ford brand or youll be sorry.
 
Hi Lynn! Did you check the 40lb back pressure valve under the acorn nut that you should have remove to get the lift chest off? I don't have a I&T manual. Don't know what is says!
 
Thanks for the replies!
Old, the valve is sticking. It was pretty obvious when looking at it on the work bench, but it got too late yesterday to investigate any further, so will try to clean//lube/etc. later, probably tomorrow.
Riveroadrat, thanks for all the info! Pump is primed & no bubbles showing. No "hiccupping" as there was no lift at all. Thanks again for the info!
Wayne, the parts of the manual I read made no mention of pressure testing. I may be in touch w/you again when I put it all back together for info on setting & checking!
Will get back to it tomorrow & will probably have more questions then.
 
OK, I'm back from the shop. Valve is now working smoothly, gasket surfaces cleaned, new gasket installed, pump prime checked again w/hose to fill opening (full flow, no air bubbles), back pressure thingy under the acorn nut visually set back to where it was. Probably will have to pressure check the pump next as there is still no lift at all.
According to the FO-19 pressure is checked at the pipe plug on top of lift cover w/a gauge w/3000 lb capacity. I don't really want to spend the money on a gauge I may never use again, so is there something else I should be doing?
Thanks again!
 
"Valve is now working smoothly" How can you tell that the unloader valve is working smoothly?? Is rubber washer in place between backpressure valve and cylinder casting?
 
Thanks JMOR. The valve was moving smoothly on the work bench & you can see the linkage moving thru the fill hole. And yes, the rubber washer is in place. Any other checks?
 
(quoted from post at 15:12:14 10/09/17) Thanks JMOR. The valve was moving smoothly on the work bench & you can see the linkage moving thru the fill hole. And yes, the rubber washer is in place. Any other checks?
he unloader valve has no linkage.
 
I'm probably calling something by the wrong name or mis-identifying something! The valve I am talking about is the control valve according to the FO19 (I think, pics are really blurry!), not unloading.
When the quadrant lever is moved I can see movement thru the fill hole. It then allows the valve to move, & I can see the rod that is attached to the valve move. At least I think that's what I'm seeing!
Does that help?
 
Spool being removed from unloader sleeve. No mechanical connection to it.
aVG3O7c.jpg
 
JMOR, that's why you're the Guru & I'm the regular! The valve I loosened was on the other end of that housing. Guess I'll be taking the cover off again & checking that one! I know what tomorrow's project will be!
Thanks HEAPS!! I appreciate your help more than you can know!
 
(quoted from post at 17:56:20 10/09/17) JMOR, that's why you're the Guru & I'm the regular! The valve I loosened was on the other end of that housing. Guess I'll be taking the cover off again & checking that one! I know what tomorrow's project will be!
Thanks HEAPS!! I appreciate your help more than you can know!
nce you unbolt & remove baffle plate you will need to punch it out from other end. Small hole there.
 
Thanks All, especially JMOR for heading me in the right direction! The lift works for the first time since I bought this tractor! Now to do some more cleaning while I have some parts off (seat, etc...) so I can eventually paint it! I started with the saddest looking Jube I have ever seen. Faded pink paint or primer, nose pushed back over 2", tires flat, etc., etc., etc....:
4587.jpg
 
This it today w/good rubber, used tin, etc.. I had to fix almost everything but the engine. It checked out really good! The 3 point was the last major repair needed!
4588.jpg
 

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