Hello I have 2640 john deere with unknown hours. The tractor has had hydraulic problems in the past and they seem to be getting worse. When I bought the tractor it had just had the brakes on the rear replaced and the rear pump replaced. Since I have had the tractor i have replaced the hydraulic filter and fluid three times in three years. The current problem I am having is I was cutting hay yesterday and the tractor was running warmer than normal but the hydraulics were extremely hot. My feet were roasting after about 4 hours on the tractor. After the tractor got hot I idled down and let cool for a little while. This brought the engine temperature down a little. I proceeded to cut hay again but when i took off I had no brakes, three point lift,nor any steering. I was wondering if you gut could give me some troubleshooting advice. Also when the tractor was hot I couldn't touch the steering column it was so hot. I have a couple of thoughts on this tractor. I think the pump is going bad due to the wining noise it makes at all time. I also believe that the steering column is leaking by and causing the system to recirculate and get hot. I was wondering if there is a good place I could start troubleshooting. I just hate to start replacing parts.
buickanddeere
Well-known Member
Is there some sort of hydraulic load that operates continuous when the mower - conditioner is running?
Have you done the classic peek into the oil filler while the rock shaft is raised and the engine operating?
Just rebuilt the power steering on my 1640. The seals were tired after 35 or so years.
Is there a loaded or any hydraulic load added ?
I was running the mower in the float position unless I needed to raise the mower. The tractor does have a loader installed. It has a remote mounted prince valve with a closed center plug installed. The supply and return for the loader are plumbed from the bottom of the tractor near the filter canister.
I have not looked in the rear of the tractor for leaks. I could get hydraulic pressure back if i reved the engine to about half throttle. Once the tractor cooled down I had pressure at idle just not when it was hot. Now sometimes with this tractor when you start it you have to let the rear pump prime the system before you have pressure.
After the brakes failed it most likely filled the trans/hydraulic system with fines, and you will be fighting this "for ever",,at this point Dynamite would be my tool of choice,,Darn it...But to start with the SCV is probably bypassing badly, and the filings have eroded the poppet valves ..start out the day with using it a bit as you touch the valves to see if they are warming up too quickly..
LOL !!! I was re reading this post and I thought to myself I bet Tim would say to blow it up ! Got to your post and Well darned if you didn't ! LOL.
Once these things get goofed up they become a nightmare. Often times sold at a sale to stick it to the next unsuspecting owner.
Once these things get goofed up they become a nightmare. Often times sold at a sale to stick it to the next unsuspecting owner.
The brakes haven't quit completely they have to be pumped. Also I feel like when I get back on it the brakes will work. How can I determine the problem with the scv. The problem only becomes unmanageable when the tractor got hot. Could you a help get a starting point for troubleshooting. Or just unload it on someone else.
buickanddeere
Well-known Member
Have to pump the brakes after they were replaced ? The master cylinder maybe worn and full of ick.
Tx Jim
Well-known Member
- Location
- Coyote Flats, Texas
It's possible the internal seal on the closed center plug has failed. Remove valve return line from tractor then start engine to determine if oil flows out of hose which would indicate a blown CC plug seal.
Tx Jim
Well-known Member
- Location
- Coyote Flats, Texas
If factory SCV it won't have a CC plug but can still bypass to sump.
Tx Jim
Well-known Member
- Location
- Coyote Flats, Texas
Yes scv can be rebuilt.Tim S a frequent poster on this forum rebuilds & tests them on his test bench. 1st do some diagnostics with a 5000# gauge. Plug gauge separately in both sides of breakaway to determine IF & how fast gauge drops after activation when control lever is moved to neutral position.
Tx Jim
Well-known Member
- Location
- Coyote Flats, Texas
Is loader valve still attached to tractor? Check steering valve for higher temp. than other hyd functions.
Tx Jim
Well-known Member
- Location
- Coyote Flats, Texas
Sounds as if steering valve has some failed o-rings. Test by capping steering supply then operate tractor a few minutes to see if hyd system operates better.
Yes it sounds like the steer valve o-rings are leaking too,,,this can be a combination of failures killing your stand by pressure, the steer valve can be lifted up and out by loosening the big nut under the wheel, the wheel can stay on, screw and lift the valve up and out, there are 6 o-rings down the hole, when you put a light in there to look it is like a small hallway full of mirrors,,be careful to get each ring in the proper groove,, the more you work on this the more you will see why I dislike them, and the complete design of it...I am helping another guy on the phone with a 2630 with similar issues,, he is considering the "Dynamite factor" too....
On the plus side I figured out what had changed. It was the scv was bypassing when in float. I pressure tested the ports and one port fell off extremely slow the other port dropped immediately. I had purchased a single spool prince valve to add a second remote to the tractor. This valve saved the day. I was able to plumb the valve in place of the original and I am back up and running. I still have a problem with the steering valve. But it can wait a week or two until we are finished with hay. I guess I am still a little unclear about how to take the steering valve apart without removing the whole assembly. Some clarification would great. Thanks again everyone for all of the help.
Tx Jim
Well-known Member
- Location
- Coyote Flats, Texas
Remove steering wheel,loosen lock nut(parts key 1) loosen large nut(parts key 4) from housing the by turning steering shaft(CCW) assembly will come out of housing with housing still attached to tractor. R&R the 6 large o-rings being careful to get each o-ring in correct location then put oil or grease on spools and reassemble.
Caution: if you disassemble valve bodies from shaft be sure to keep components in their exact locations.
(quoted from post at 08:26:19 06/08/16)
Remove steering wheel,loosen lock nut(parts key 1) loosen large nut(parts key 4) from housing the by turning steering shaft(CCW) assembly will come out of housing with housing still attached to tractor. R&R the 6 large o-rings being careful to get each o-ring in correct location then put oil or grease on spools and reassemble.
Caution: if you disassemble valve bodies from shaft be sure to keep components in their exact locations.
So I have removed the steering valve from the housing. How do you go about replacing the o rings down in the housing. Also does the internal shaft need to be disassembled and rebuilt. Prior to disassembly the steering wheel had about a quarter turn of play and raised up about 1/2 to 3/4 of an inch.
http://i1146.photobucket.com/albums/o523/cowman79/20160703_211808_zpsiyivffvz.jpg
http://i1146.photobucket.com/albums/o523/cowman79/20160703_211816_zpsiw2guc98.jpg
Tx Jim
Well-known Member
- Location
- Coyote Flats, Texas
Normally steering shaft/wheel raises up/down a little bit during operation. I read on other tractor sites of technician making a long tool to aid in R&R of o-rings. Steering wheel play is normally in the mechanical linkage all the way to tie-rod ends not the valve.
Thanks for the information. It seems like their I aa decent amount of play in the steering. When you drive down the road it is a challenge to keep between the lines. I cannot seem to find any slop in the external linkages. I didn't know if their was worn spacers or a bushing that needed replaced.
Tx Jim
Well-known Member
- Location
- Coyote Flats, Texas
Have you checked brgs in bellcrank? These brg's have a long history of failure from grease worms eating on them.
I am not sure if this is a problem but when i put the steering valve on the bench to start the tear down I noticed that the outer rings could slide back and forth about a quarter of an inch. I am not sure if this is normal. it appears that their are several areas that have shims installed. I am not sure if this unit needs to be shimmed to a certain specification or if this is normal. I have attached a picture you can see the space between the ring at the bottom of the spring. Their is a black mark perpendicular to the area with the gap.
Tx Jim
Well-known Member
- Location
- Coyote Flats, Texas
Yes valve bodies must be shimmed to certain spec's. I don't remember the spec's. You need to acquire a JD tech manual for your tractor. As I previously stated it is very important to keep steering shaft components in original locations.
Tx Jim
Well-known Member
- Location
- Coyote Flats, Texas
No reason to disassemble steering shaft with valves unless tractor isn't steering correctly one or both directions
darrin9884
New User
I lost all my hydraulics in a similar manner I've read all kinds of post to try to figure it out. Check every idea everyone said try, with no results. But I did find it and it was such a easy way just to check, I lost my hydraulics because of the clutch. On the side of my 2640 was a round inspection plat to see the clutch with a light I could see the star shape plat that is riveted in. It busted the rivets and that drives the transmission pump witch supplies oil to start every thing to run, replace the clutch got all my hydraulics back. Down side of my job is I had to separate the tractor and put the clutch in the pastor not fun but got it.
Glen D Anderson
Member
Welcome to YT!
And thanks for sharing that info. That's the good stuff that helps people when they're searching the 'net.
And thanks for sharing that info. That's the good stuff that helps people when they're searching the 'net.
buickanddeere
Well-known Member
TimS has the knowledge ,tools and equipment to make the SCV better than new .
The only drawback is now the rest of the tractor is now going to appear lousy when compared to the SCV.
buickanddeere
Well-known Member
Thought the rad and oil cooler was clean on my tractor from being blown clean and washed with a stream of hot water from the garden hose .
Had the front end apart later was actually able to see straight through the rad and oil cooler . They were nowhere as clean as I thought they were .
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 © 1997-2025 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