John Deere 401C Hydro trouble

85bj60 · Oct 24, 2020

Local dealer is no big help! That's a pricey housing

I will have to check if housing is good. Thx for replying

true temper · Oct 24, 2020

What makes you think its bad.

85bj60 · Oct 24, 2020

I've bypassed it and everything was working like it suppose to. I reconnected it after taking it apart to make sure no dirt was in it. I also plugged the rear selector to take it out of the equation and it's back to the woes again.

Zebrafive · Oct 26, 2020

85bj60 said:
I've bypassed it and everything was working like it suppose to. I reconnected it after taking it apart to make sure no dirt was in it. I also plugged the rear selector to take it out of the equation and it's back to the woes again.

How did the internal parts look? How did the valve fit the bore of the housing? Loose? Tight? Seized? If I were to "throw" parts at it, I would start with the spring, then the internal valve assembly.
Or try and find a used complete valve.

85bj60 · Oct 26, 2020

I found it to be tight when re-inserting and was slipping up & down by gravity at times. There was some wear marks but not really noticeable. Spring length was just a tad short of 4 5/8". There was a third shim which was slightly bigger than the other two. I placed it at the other end against the plug in case it rubbed on the valve. I would have to know if the housing is in good shape before throwing some parts into it. My neighbor has a pressure regulator which I can adapt to it if I choose to go that route.

https://static-assets.imageservice....bout-safety-valve-and-vacuum-relief-valve.png Something similar to this

Tx Jim · Oct 27, 2020

If it was my tractor & hyd operated well by bypassing pressure control valve I'd just leave it bypassed. My understanding is pressure control valve is designed to give priority hyd pressure to power steering. Simple solution don't operate any other hyd function while turning steering wheel then hyd problem solved.

85bj60 · Oct 28, 2020

Tx Jim said:
If it was my tractor & hyd operated well by bypassing pressure control valve I'd just leave it bypassed. My understanding is pressure control valve is designed to give priority hyd pressure to power steering. Simple solution don't operate any other hyd function while turning steering wheel then hyd problem solved.

Sounds like a super simple solution and hopefully doesn't causes problems down the road. I'll add a T so I have flow to my rear selector. Adding the mentioned pressure regulating valve will give me peace of mind of not over pressuring the system on my doing. :thumbsup:

Tx Jim · Oct 28, 2020

My knowledge of JD "utility tractors" is limited BUT on AG tractors with a similar pressure control valve this PC valve doesn't control system pressure. As I previously stated PC valve provides hyd priority pressure to power steering. The stroke control valve in frt hyd controls system hyd pressure. Does your 401C have a 3 pt hitch??

85bj60 · Oct 29, 2020

Yes, it does have a 3pt hitch! When time permits me to redo the hydraulic routing I'll report back on the findings. Thx again

Tx Jim · Oct 30, 2020

Isn't 3 pt hitch supplied hyd oil via a galley in trans case supplied by hyd pressure from pressure control valve?

85bj60 · Oct 30, 2020

Tx Jim said:
Isn't 3 pt hitch supplied hyd oil via a galley in trans case supplied by hyd pressure from pressure control valve?

I have no clue, never seen the internals of the transmission (not yet and crossing the fingers of keeping it that way, lol)
I know the small opening leaks oil into the pressure control valve and the bigger opening doesn't drip back, that's as far as I know.

85bj60 · Nov 8, 2020

Could the small hole of the transmission feed the rear selector is my question?
I'm gonna tap my new pressure regulator into the existing defective pressure regulator to direct over pressure flow and T the working flow towards the rear selector if needed.

Tx Jim · Nov 9, 2020

IIRC there is a oil galley where PC valve attaches to trans case that supplies pressure oil to RS housing sealed between trans case & RS housing by a quad ring(T17882)

85bj60 · Nov 9, 2020

That's what I figured and if it isn't, plugs and T fittings will do the trick!
I'll take a pic when I get to it

85bj60 · Nov 19, 2020

Zebrafive said:
What parts do you need for it? Looking an JD parts, parts appear to be available, most are O-rings, fittings, the internal valve and spring are available. If the housing is OK, you should be able to get any internal part. The housing is BIG money, but available too. $1625

Can anyone tell me what #5 (dowel pin) is for? There isn't one in mine. I was able to find the parts through another JD dealer. Waiting for calls on used/new parts in the meantime.

Zebrafive · Nov 20, 2020

85bj60 said:
Can anyone tell me what #5 (dowel pin) is for? There isn't one in mine. I was able to find the parts through another JD dealer. Waiting for calls on used/new parts in the meantime.

The AG version does not have the pin key 5. It also does not have the cap at the rear key 17. So my guess is the pin is to prevent the internal parts from coming out the front/forward end of the housing, if the fitting for the hydraulic line is removed. Key numbers are for 401c PVC First drawing. Second drawing is for JD 2030 AG tractor PCV

85bj60 · Nov 21, 2020

That makes sense on the different housings usage but I can't find where the dowel pin is inserted. I gather you don't have a FEL on your 2030.

Tx Jim · Nov 22, 2020

85bj60;5866816 I gather you don't have a FEL on your 2030.[/QUOTE said:
IIRC Z5's 2030 has a FEL. But whether Z5's 2030 has loader installed or not has no bearing on pressure control valve configuration & related parts or not. All 2030's came from factory with pressure control valve & no FEL attached. Also ag tractors were manufactured with some different parts than industrial tractors.

Zebrafive · Nov 22, 2020

85bj60 said:
That makes sense on the different housings usage but I can't find where the dowel pin is inserted. I gather you don't have a FEL on your 2030.

My 2030 has JD 245 loader, see my signature. Pressure is connected by a tee after (behind) the PCV. Return is to a ported transmission filter housing.

85bj60 · Nov 22, 2020

Tx Jim said:
IIRC Z5's 2030 has a FEL. But whether Z5's 2030 has loader installed or not has no bearing on pressure control valve configuration & related parts or not. All 2030's came from factory with pressure control valve & no FEL attached. Also ag tractors were manufactured with some different parts than industrial tractors.

Total blindness on my part :confused 3: So a PCV of a 2030 or among others can be fitted on a 401C if I'm reading this correctly. This would greatly increase the odds of finding a used one or a cheaper new one. Also thanks to Zebrafive!