Jubilee hydraulic fluid

[Al in Il.]

I changed hydraulic fluid on my Jubilee and now there is foam in it. I don't see why this fluid pictured wouldn't work - any reason? It is compatible with the original requirement.

 

[Sean in PA]

Foam sounds like a slight air leak in the circuit on the suction side of the pump.

 

[Al in Il.]

Sean, I have a vane type pump on my Jubilee. Can you suggest specific spots to check? Thanks for the reply.

 

[Sean in PA]

An NAA with a vane pump should have two separate hard lines going from the pump to the bottom of the hydraulic sump. The slightly larger diameter line that connects to the pump in the more rearward spot is the suction line. There should be o-rings to seal the lines at both ends. The air leak could be at the o-ring at either end or it could be pinholes in the line itself. The first thing I would do is drain the hydraulic fluid so it doesn't all leak out, then remove the suction line and rig up something to put compressed air into it under pressure and use soapy water on the outside to see if you get bubbles that would indicate any pinholes in the tube. If there is you should be able to braze the hole(s) and put it back together with new o-rings. If there's no pin holes then put it back together with new o-rings.

 

[jimtrs]

(quoted from post at 07:24:30 06/22/21)The air leak could be at the o-ring at either end or it could be pinholes in the line itself

While moving the hydraulic pump to the engine gave live hydraulics on these early Fords, a welcome change, running the manifold lines under the tractor was not one of Fords better idea's. Brazed up more than a few. I think they moved them inside after this model. If the manifold lines are crushed, or have been rubbing, probably a leak there. As Sean said foam is usually air. Suction line would suck in air, pressure line would squirt oil.

 

[Al in Il.]

Sean, I'll check the lines tomorrow hopefully. Fortunately there are no leaks anywhere, although it does make it harder to pinpoint, nothing
obvious. Thanks for the reply.

 

[Sean in PA]

(quoted from post at 19:50:26 06/22/21) Sean, I'll check the lines tomorrow hopefully. Fortunately there are no leaks anywhere, although it does make it harder to pinpoint, nothing
obvious. Thanks for the reply.

leaks that are just big enough to let air get sucked into the suction side of the system are not always large enough to allow the oil to leak out, especially on the suction side, as that part of the circuit is never under pressure. Air will pass through spaces that are too small for oil to pass through. The individual hydrocarbon chain molecules that make up the oil are tens to hundreds of times larger than oxygen and nitrogen molecules in the air.

 

[sotxbill]

That fluid should work fine. Pumping fluid will create some minor foam. The exhaust (return) port from the 3 point can do that as well. If it primes quickly when starting, your probably okay.

 

[Al in Il.]

I took the suction line off today and replaced with new O rings. The lines were in great shape, a pressure test verified but now I know for
sure. I have put in new: steel check ball and valve, cylinder lift piston O ring and leather washer, top cover gasket and new O rings for the
auxiliary valve on the top cover and hydraulic fluid. I can still see fluid coming out (towards radiator) the opposite side of the
control/relief valve. I still have foamy hydraulic fluid - looks like it's coming from the leak. Will a bad control valve make fluid foamy?