64 4000 Power Steering leak at control valve

Dirtsmith

Member
Hi All,

My 64 4000 developed a leak on the pressure side tube of the control valve. I have unscrewed the tube and examined it to see if it was broken or cracked; it is not. The nut was secured well and required a bit of force to loosen the nut. The flared end of the tube did not appear to be crushed our mishapened. I don t see that there was any type of o-ring needed, based on this diagram: https://partstore.agriculture.newholland.com/us/parts-search.html#epc::mr60169ar258649

When the tractor is running, fluid flows from the pressure side. It does not spurt. This of course means that the reservoir is empty now too. I still have plenty of Multi G 134 left to refill it with so I at least I don t let it run dry. Only the best for my driveway...

On a separate note, water appears to be getting into the system. This tractor has a roller vane pump. The reservoir lid is secured with the clamp and screw. The gasket is new.

I am immediately concernd with the leak from control valve, any thoughts and/or suggestions about the cause or potential fix, are greatly appreciated.
 

Ok, so as I said, I pulled the tube off and inspected It, cleaned what I could, and put it back. I started the tractor, used to loader, raised the front wheels of the ground, and turned them left to right to activate the power steering.

The fluid is coming out of the valve between the tube and the nut that slides over the tube to secure it.

Does this information help identify the cause of the leak?
 
I had a similar leak on my 3000.
What I found was an almost microscopic
crack just inside of the flare nut.
Could not see it with my naked eyes.
I sanded down a piece of wood and drove
it into the end of the tube and poured a
mix of water and dish soap into the
tube. Took my blow gun and put about 75
psi air pressure to the other end and
sure enough had bubbles.
Also had a similar leak on the pump end
of the pressure line on another tractor
I had.
I'm convinced both failures were caused
by vibration as neither tractor had all
the oem clamps that secure the lines to
the hood. I made a couple of clamps and
haven't had a leak on those lines in at
least 10 years now.
 
Thank you, Ultradog.

I think I am following what you are saying and I should be able duplicate your testing method.

If what you encountered is the same as what I am experiencing, then replacing a tube would be a far better solution than disassembling the steering column and trying to dissect the control valve to find a problem.

I ll take a pointed look at the clamps securing the lines too. I appreciate your insight. Thank you.
 
Hi Ultradog.

I [b:222d7344cf]THOUGHT[/b:222d7344cf] I had figured out how to duplicate your test on the pressure tube, but I am wrong. I am not sure how to do it.

If there is a leak or crack in pressure tube, it appears to be at the flared end of the tube that seats into the control valve. The fluid seems to coming out through where the tube passed through the nut that secures the tube to the control valve. I don't see how I can pressurize that area of the tube where I think the problem is. Anything I would stick into the tube would go past where I think the leak is.

I can certainly set an air gun to 70 psi and I know how to make soapy water, but If there is a problem and it is in the end of the tube secured by the nut at the control valve, I am just not seeing out I can test that.

Perhaps, if I sand down a board to be very smooth, then bore a shallow hole with a Forstner bit that has the same or nearly the same Outside diameter of the flared end of the tube, then put heavy pressure on it as I blow air into it from the pump end of the tube and see if soapy water bubbles out that way.

hrmmm... maybe that will work....

Still, I am open to other thoughts or ideas of what might be causing the leak. A leak that did not exist prior to it going into the shop. So frustrating....
 
You could have a bad flare seat. There's a seller on fleabay that sells copper flare washers that work good because they are soft and fill the voids when tightened. Some of the smaller lines to the cylinders I had to put them on a punch and grind them a little to make them fit in the hole. They worked though.
 

"Flare seat" - that sounds like what the items is that I am looking for would be called.

I have been trying to come up with a way to fill the void around the tube and the nut to see if that would close up whatever is causing the leak. Of course there is already a product on the market for what I am trying to do!

It might only be a temporary fix, but it would be something to get me going again.

I'll look up what you are saying. Thank you for very much for the suggestion, that might be just what I am looking for.
 
I am still trying to figure out what the cause of the leak is.

With the tube disconnected at both ends to get a better look, I could not find any sort of crack or break or deformation on the flare or the nut.

With no other options immediately available to me, I decided to try to clean the physical connection to see if that would change anything.

I did not 'fix' or stop the leak, i was just trying to clean out any junk using metal picks and a cleaning cloth to get rid of 'gunk'.

After re-assembly, I started the tractor, throttled up to see how much oil was pumping out. Fluid still leaked but it was much slower. So, did I actually do anything, or, did I just re-seat the flare better and reduce the gap for fluid to escape through?

IDK...
 

The problem was in fact the hard line itself. I never found the crack in the line, but it must be there because it leaked like a sieve.

Anyway, I opted to go with the rubber hose for about 1/2 the price of the OEM part. Once it was installed, the leak stopped and power steering worked again.

That issue is now resolved and the next one has already appeared. Joy.
 

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