- Thread starter SVcummins
- Start date
I was looking at the pump you took out,,it looked very good,,I was sure nothing would change after you installed the new one.The flow to the front pump does not take much pressure..just a steady flow,,you probably have a high pressure leak some where, capping and isolating each component will help sort that out.
cornerpost
Member
Sorry if asked on other post. Is your loader plugged into remotes, plugged into a remote with hoses to loader valve mounted on mast or fender; or plumbed into line feeding high pressure oil to remotes and hitch rock shaft.
Remove the coupler end on the return hose and point it to a bucket, then activate the SCV in the direction that it takes to charge the loader valve,, there should be very little to no oil going into the bucket,,,if there is the valve is letting oil through,,and this can be the problem..
tomstractorsandtoys
Well-known Member
Go to 2200 on the pressure. My 4020 was at 1900 and started having some hyd issues. It never would run a hyd motor. Adjusted it to 2200 and everything works fine. Even used it to drive a hyd motor for a few hours. Tom
wore out
Well-known Member
After the tractor has cooled off overnight, start it and listen for rushing/flowing noises at all the high pressure hydraulic components and note the temperature rise at each as the machine warms up.
A component with an internal "high pressure leak to sump" will be making noise and will warm up faster than the tractor chassis.
An "infrared heat gun" is helpful for this. The SCV's, steering valve, brake valve, and hitch valve shouldn't get warm(er) any quicker than the main transmission case so long as none of those functions are being used.
Tx Jim
Well-known Member
- Location
- Coyote Flats, Texas
Yes you'll need new quad rings(2 ea- R26149) & 3 ea-3/8" X 3-1/2 cap screws
Tx Jim
Well-known Member
- Location
- Coyote Flats, Texas
Only way to correctly answer that question is by utilizing good hyd diagnostic procedures!!!!! Large internal high pressure leak can rob frt pump of pressure because trans pump doesn't have the ability to furnish enough oil.
Don’t know what else to check on the transmission pump
circuit, new pump new gaskets new orings started the tractor
with rockshaft housing off can’t see any oil spraying out of
anywhere no leaks ? Plumbed the external hydraulic valve in
rider and that seemed to fix the problem but it to has an
external leak because it gets hot hot hot and you can hear the
oil bypassing the valve inlet hose and drain hose and even
main hydraulic cylinders get very hot but it still works better
than off the tractor scvs .
circuit, new pump new gaskets new orings started the tractor
with rockshaft housing off can’t see any oil spraying out of
anywhere no leaks ? Plumbed the external hydraulic valve in
rider and that seemed to fix the problem but it to has an
external leak because it gets hot hot hot and you can hear the
oil bypassing the valve inlet hose and drain hose and even
main hydraulic cylinders get very hot but it still works better
than off the tractor scvs .
Tx Jim
Well-known Member
- Location
- Coyote Flats, Texas
When you checked trans pump pressure/flow what were the readings? Have you checked hyd operation with each hyd component individually capped off?
Jim I can’t get the transmission pump to make 20 psi with the
valve closed . I capped the three point Off no change capped
the scvs off and plumed loader through my external valve and
the loader worked great for a few minutes until the oil and
valve got hot it has an internal leak you can here the oil
bypass inside the valve with it in neutral I put a conversion
plug in it to change from open center to closed center but it
had other problems internally.
valve closed . I capped the three point Off no change capped
the scvs off and plumed loader through my external valve and
the loader worked great for a few minutes until the oil and
valve got hot it has an internal leak you can here the oil
bypass inside the valve with it in neutral I put a conversion
plug in it to change from open center to closed center but it
had other problems internally.
Tx Jim
Well-known Member
- Location
- Coyote Flats, Texas
Have you checked hyd filter relief valve to be sure it's not stuck open?
buickanddeere
Well-known Member
The loader control valve has been operated open centre until now ?
Just hooked the loader valve on I have running on scvs until
now even with the loader valve the way it is it still works Better
than it was on the scvs ran the loader off the scvs since 2005
this winter it started taking longer and longer for the hydraulics
to start working so I tested the transmission pump decided
was bad changed it worked better but still not right . Number
one scv gets hot after about 5 minutes of idling
now even with the loader valve the way it is it still works Better
than it was on the scvs ran the loader off the scvs since 2005
this winter it started taking longer and longer for the hydraulics
to start working so I tested the transmission pump decided
was bad changed it worked better but still not right . Number
one scv gets hot after about 5 minutes of idling
buickanddeere
Well-known Member
Sounds like those SCV need to be setup on TimSs calibration bench . The setup he has there Is the best that I have seen in a long time .
johnyquest69
Member
I found a Koyker loader off of a 4430 and put it on mine. Was very slow and jerky. This loader had a joystick. I took the return hose coupler end off that was plugging into my scv and pointed into bucket per Tim S. I found I had a flow of oil into bucket while joystick was in neutral. The guy who had this loader had been running valve as open center the whole time. I ordered a fitting from Koyker that changed the joystick to closed center. Solved my problem. I then added a power beyond to free up my scv. Ive used a gauge to see pressure on scv while lever in neutral to know it was leaking by.
I ordered a plug to change the valve and it didn’t work I can
feel the oil and hear it bypassing the valve and the valve gets
so hot after about 5 minutes you can’t touch it so I know it’s
bypassing even though it shouldn’t but the valve is 50 years
old so it could have an issue at the end of the day even with
the valve leaking it still works better than it did when hooked
up to the tractor scv .
feel the oil and hear it bypassing the valve and the valve gets
so hot after about 5 minutes you can’t touch it so I know it’s
bypassing even though it shouldn’t but the valve is 50 years
old so it could have an issue at the end of the day even with
the valve leaking it still works better than it did when hooked
up to the tractor scv .
wore out
Well-known Member
You are saying it's bypassing in the valve mounted on the loader, correct?
Most likely, there's a relief valve in that valve and it isn't set high enough to contain the 2250 PSI from the tractor.
Crank that relief down as tight as it will go, it isn't needed with your closed-center system because the controls on the 4020's hydraulic pump take care of limiting hydraulic pressure.
Just the OPPOSITE of how things would work if that loader was fed from an open-center PTO pump, in which case the relief in the loader valve is DEFINITELY needed.
Tx Jim
Well-known Member
- Location
- Coyote Flats, Texas
Ditto about what wore out stated about relief valve.
Tx Jim
Well-known Member
- Location
- Coyote Flats, Texas
Same scv utilized on early model 3020 & 4020.
Pulled the hose coming out of the bottom of the farmhand valve today and started the tractor and just like I thought it’s letting oil passed with the valves in neutral so that valve must have internal problems the relief valve on it is cranked as tight as it will go .
Tx Jim
Well-known Member
- Location
- Coyote Flats, Texas
I suggest removing Closed center plug to check to be sure internal seal on plug is not blown!!
Tx Jim
Well-known Member
- Location
- Coyote Flats, Texas
I learned by the difficult method way back 50 yrs ago if the inner seal FAILS on closed center plug shown in photo below then closed center hyd's will not function as designed!
Tx Jim
Well-known Member
- Location
- Coyote Flats, Texas
All closed center conversion plugs(key 12A or 12B) I've ever seen resemble the plug in the photo I previously posted. You probably have an open center plug(key 12C) that was utilized before "power beyond" was created.
Tx Jim
Well-known Member
- Location
- Coyote Flats, Texas
IIRC control valve in parts schematic is a Gresen brand & closed plug from JD is NLA. I found the closed center plug in photo below but it's for a Prince valve & I'm not sure it will fit your valve.
Tx Jim
Well-known Member
- Location
- Coyote Flats, Texas
If your control valve is a Gresen then Bailey Hyd's shows to have a CC plug for model SP,SPK & SSK control valve.
Tx Jim
Well-known Member
- Location
- Coyote Flats, Texas
I think CC plug(8650-134) I posted above will fit a 2712 valve body
Tx Jim
Well-known Member
- Location
- Coyote Flats, Texas
A very long time ago when I was 1st learning about JD CC hyd systems I discovered a blown seal on a similar valve on a JD 2020 with a 48 loader after several hrs of diagnostics. I never forgot about that learning experience! You're welcome,Jim
Thanks jim . This valve came with the farmhand loader when i bought it was originally ran off the pto pump . Was really hoping it could be converted then i found conversion plug and got it then it isnt right crossing my fingers that someone can get the right plug . Bailey kindly informed me that they dont stock gresen parts .
Tx Jim
Well-known Member
- Location
- Coyote Flats, Texas
It's immaterial what implement your valve came with or what type pump supplied pressure for it. I'll bet there's a closed center plug that will fit it.
wore out
Well-known Member
I think I figured out what's going on... The way it's set up you need the "power beyond" plug because there's a second valve, but the "power beyond" plug doesn't work with "closed center". The fix would be to get the "closed center conversion plug" and eliminate the second valve. (IF you can live without the third spool.)
It's possible there's a "closed center conversion plug" available for the second valve, if so you could install that and "T" the pressure line from the tractor to the inlets of BOTH valves.
That's how closed center systems work, a common pressure line is "T'd" to all valves, the opposite of an "open center" system were valves are in series.
Similar threads
We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.
Copyright © 1997-2024 Yesterday's Tractor Co.
All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.
Yesterday's Tractors - Antique Tractor Headquarters
Website Accessibility Policy