John Deere 401C Hydro trouble

85bj60 · Dec 15, 2020

Or is it a three-way valve I need?

Zebrafive · Dec 16, 2020

85bj60 said:
Ok, I plugged the weeping hole(and leaving the valve in the PCV, couldn't justify removing it yet) and I'm still in my woes of no FEL operation. I'm thinking of adding a two way 12V valve to split the two functions, FEL & RS. Or maybe a hydraulic one....
I'm in the winter season and playing around with this hydraulic system is starting to get long & cold!

By plugging the "weeping hole" (which I think you mean the hole to let oil from the spring side of the internal valve go to sump), BUT NOT removing the internal valve, you caused the internal valve to "hydraulic" lock. With out the weep hole, the valve can't move, even if there is enough pressure in the system.
Unlike an AG PCV, you only have to remove the rear plug to access/remove the internal valve. Remove it and try that. If you still have problems, that only leaves the Rockshaft. Leaking valve or cylinder.

85bj60 · Dec 16, 2020

Zebrafive said:
By plugging the "weeping hole" (which I think you mean the hole to let oil from the spring side of the internal valve go to sump), BUT NOT removing the internal valve, you caused the internal valve to "hydraulic" lock. With out the weep hole, the valve can't move, even if there is enough pressure in the system.
Unlike an AG PCV, you only have to remove the rear plug to access/remove the internal valve. Remove it and try that. If you still have problems, that only leaves the Rockshaft. Leaking valve or cylinder.

That makes sense to me, I plan on removing the innards. Good catch!

85bj60 · Dec 22, 2020

Removed the internal valve and still the same woes. I checked for flow of oil inside the tranny but I don't see any, I must be blind or could be low on oil. Will check it again when time permits. Might have to get a 3way valve for the winter.

Zebrafive · Dec 24, 2020

85bj60 said:
Removed the internal valve and still the same woes. I checked for flow of oil inside the tranny but I don't see any, I must be blind or could be low on oil. Will check it again when time permits. Might have to get a 3way valve for the winter.

I think this narrows it down to the rockshaft/3pt hitch.

85bj60 · Dec 24, 2020

Zebrafive said:
I think this narrows it down to the rockshaft/3pt hitch.

I hope this a somewhat easy pull out assembly to work on a table. It will have to wait for Spring.
Thx again and a safe Merry Xmas!

Zebrafive · Dec 25, 2020

85bj60 said:
I hope this a somewhat easy pull out assembly to work on a table. It will have to wait for Spring.
Thx again and a safe Merry Xmas!

Merry Christmas! I have never had one (rockshaft) apart, but I bet TX Jim has seen a lot of them worked on.

Tx Jim · Dec 26, 2020

Yes I've witnessed several JD utility 20-40 series tractor rockshaft housings removed & resealed The seals aren't near as difficult to R&R especially when comparing to other JD tractor valves that require adjustment with a micrometer.

I hope everyone had a Merry CHRISTmas & will have a happier New Year.