Well its not

SVcummins · Sep 15, 2020

The rockshaft leaking oil . Capped the supply line and no change . Guess the brake valve and steering valve next

wore out · Sep 15, 2020

I don't recall if you've capped the suppliy to the SCV's?

SVcummins · Sep 16, 2020

Yessir they’re capped and are atill capped. Seemed ok after I capped off the rockshaft for a couple cycles then right bsck to not enough oil

wore out · Sep 16, 2020

So you have to figure out where the oil is going that's supposed to be returned to the front pump.

This is a pre-side console tractor, IIRC?

Do you have the official SM2039 manual?

Have you checked the hydraulic oil filter relief valve... read the second paragraph below. Note that if something is wrong at the relief valve some oil would be dumped to the transmission case rather than going forward to the hydraulic pump.

<img src = "https://i.imgur.com/fWfnLnU.jpg">

<img src = "https://i.imgur.com/VhcCC8I.jpg">
Note how the function return oil and oil from the transmission pump combine at the filter, then are routed to the front pump, with the excess flow then flowing upward, filling the reservoir, then returning to the transmission.

Tx Jim · Sep 16, 2020

I agree with wore out that a faulty hyd oil filter relief valve could be your tractors hyd problem.

SVcummins · Sep 16, 2020

So where is the relief valve actually

SVcummins · Sep 16, 2020

Got the valve off . Im guessing there should be spring pressure against this valve

SVcummins · Sep 16, 2020

Any ideas

SVcummins · Sep 16, 2020

Can someone find the length of the spring from the part number

Tx Jim · Sep 17, 2020

JD has decided recently too much parts information was available on the internet so they either deleted parts spec's or relocated the info to where I can't access parts spec's. I looked in SM2038 for 3000 series & if spec's are listed for that spring I overlooked the spec's. Filter relief valve is designed to only open in "cold weather or clogged hyd filter" . Is valve free to move in housing?

SM does mention that a check valve in trans case could be at fault accessed by removing rockshaft

SVcummins · Sep 17, 2020

Ya there is a check valve as well . The spring doesn’t apear to be broke and it doesn’t look to be compressed or distorted. Book really doesn’t say

SVcummins · Sep 17, 2020

The valve is free in the housing. I may order a spring since its cheap just to see but my guess is thats not the issue either

M-MAN · Sep 17, 2020

JD Parts wasn't any help other than to show that spring being used everywhere. that's why it's so cheap.

Not sure if I pulled up the correct diagram for yours so you need to double check it. I saw a plug on the end that you don't have in the pic. That would explain the spring being short???

SVcummins · Sep 17, 2020

I guess ill keep looking this turned out to be no luck either.

Looks like the spring has bounced off the plug a few million times over the last 53 years

M-MAN · Sep 18, 2020

Did you check the parts file to see if there is supposed to be a plug on the other end of the spring?

Scott 730 · Sep 18, 2020

Looks like the spring has bounced off the plug a few million times over the last 53 years

The plug shown on JD parts for an early 4020 looks different that yours.

SVcummins · Sep 18, 2020

Its the same plug its had since 1967 . I really don’t think this is the problem

SVcummins · Sep 19, 2020

I can’t see anything missing from my valve according to the parts breakdown. It does look like in the diagram the plug they show has a t!t on it for the soring to sit on and keep it centered. It would be interesting to know if that spring should hold pressure again that plug ?

Tx Jim · Sep 19, 2020

SV
If I was diagnosing your tractor & the weather temp's were above freezing & hyd filter had relatively low hrs of use I would shim the hyd filter relief valve very snug for a experiment. I would also re-check output in GPM's of trans pump.

IIRC you did state when you disconnected your new FEL 3 spool valve return line then start engine with all 3 spools in neutral & NO OIL exited open hose?????

SVcummins · Sep 19, 2020

No oil coming through the new valve not even a drop . One
thing I forgot was there is some oil coming up the hose from
that valve which is where my return oil is plumbed in . I will
shim the valve and see what hspoene . Won’t be until later
today sometime

Tx Jim · Sep 19, 2020

I think oil exiting hose attached to rockshaft return oil port originates from trans oil pump which shouldn't affect overall hyd system performance

SVcummins · Sep 19, 2020

SVcummins · Sep 19, 2020

Shimmed the valve still no change . Have to pull the rockshaft housing and find the check valve

Tx Jim · Sep 20, 2020

If that 4020 was under my supervision I would perform some more diagnostics before removing RS housing to inspect check valve.

SVcummins · Sep 20, 2020

What else should i do ? Im all ears all ive got is time ? Need to make it work its not my hobby tractor and i need to know what it needs to fix it . I worry about not enough oil going to lubricate the transmission or something else before i hook it to the plow for the next two months

Well its not

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Similar threads