1958 420w touchomatic seal replacement

[JaimeW]

Hi everyone.

The hydraulics on my 420 gave up the ghost last week. Before it went, implements would 'bounce' up and down, which I read is a sure sign that the seal on the hydraulic piston is leaking.

Anyway, I have the two cylinder touchomatic system. I don't have my manual handy, but if I recall correctly there are a couple of places where seals can fail in there - on the piston and the check valve.

Can anyone tell me what those part #'s are and if I've missed some other place.

Also, my 3pt hitch is leaking out of the left side of the rocker shaft. Is there a seal to replace there? I put in a cork seal and metal retainer, but that didn't work. I don't see how it could work, because the cork seal is right over the splines, which is where the fluid leaks. Is there another seal I'm missing somewhere?

Thanks for your time!
jaime

 

[Devon Hubbard]

Jamie,

If you have service manual, it is not that difficult to tear down and rebuild the hydraulic system on your 420. I did one a few years ago. Should have done it about ten years prior.

The rockshaft on my 420 did not have any bearings. It just ran in an oil bath and was metal on metal. The problem after 50 years or so, is that the rockshaft becomes egg shaped & the oil seals will not last. The later 430 tractors had essentially the same components, but had brass bushings on the rockshaft. Much better. I bought the bushings for the 430 & took the bushings and my rockshaft to a machine shop. They machined the rockshaft to accept the bushings. Much better......

 

[JaimeW]

Did you have to buy the seals from JD, or can I pop them off and find replacements at my hardware / auto store?

Thanks,
jw

 

[Devon Hubbard]

I bought the seals at the JD dealer.

After thinking about this a while, I remember that I had the rockshaft housing machined to accept the 430 bushings. They pressed them into the housing. The bushings are kind of a honeycomb oilite material about 2" wide, maybe 1/8" thick. The I.D. matches the rockshaft.