Deere 2940 selective control valve

[RonaldK]

Recently, I have hydraulic oil coming up through my selective control valve arms. I am looking at a parts diagram and see that there is a washer in the valve. I am hoping that this will be a quick fix. Anyone have experience with this problem. It is just a very slow leak.

 

[Tx Jim]

If oil is coming out in between valve housings or either side of valve body is an easy repair as long as oil isn't coming out around operating shaft.

 

[RonaldK]

Thanks for the advice. It is just seeping around the control arms.

 

[Jim.ME]

Thanks for the advice. It is just seeping around the control arms.

AsTx Jim said seeping between the housings is a fairly easy fix, control lever shafts is a different story.

I may be wrong on this but, if it is seeping around the shafts the levers hook to, I would not say it is "a just change a seal washer" fix. The cam assembly that works the valves inside the SCV body is pinned to that shaft. The pin has to be removed to get the shaft out. There is an O-ring in a groove of each housing that seals to the shaft. It can be done but one can mess up the valve settings in the process. Post a picture or two of your SCVs including the leak area.

 

[RonaldK]

This is where I see the guild when tractor is running. It is just a film of fluid nothing is dripping out.

AsTx Jim said seeping between the housings is a fairly easy fix, control lever shafts is a different story.

I may be wrong on this but, if it is seeping around the shafts the levers hook to, I would not say it is "a just change a seal washer" fix. The cam assembly that works the valves inside the SCV body is pinned to that shaft. The pin has to be removed to get the shaft out. There is an O-ring in a groove of each housing that seals to the shaft. It can be done but one can mess up the valve settings in the process. Post a picture or two of your SCVs including the leak area.

This is where the fluid shows when the tractor is running. It isn’t dripping out. I just creates a film over the area shown.

 

[Jim.ME]

This is where I see the guild when tractor is running. It is just a film of fluid nothing is dripping out.

This is where the fluid shows when the tractor is running. It isn’t dripping out. I just creates a film over the area shown.

I marked up a several pictures form the pars catalog. The picture of the two valves is from a 2355 parts catalog as I didn't see the dual valve setup in the 2940 catalog. From working on several of these I believe the internal seals between the bodies are the same, rebuilding uses the same seal kit. The 2355 uses different top covers ported for return oil, yours returns from the side of the valve closest to the rockshaft cover directly into the rock shaft cover, so your top covers are not ported.

Tx Jim may say different, but I am going to say unless you really want to learn about JD SCV valves and how to adjust them, do not try to change the O-rings for the lever shafts. It is easy enough to separate the two valve bodies and replace the two R26149 packing seals that are between them. Changing the top cover R49187 washers is not a bad job either. Beyond that you want the correct JD manual for your tractor, the special tool they have to hold the poppets for adjusting, a dial indicator set up and a lot of patience. Take pictures and track where every valve, spring, bushing, etc. goes so they return to the same holes.

 

[RonaldK]

Unless I hear something completely different I plan to follow your suggestion. Thanks

 

[Tx Jim]

I agree with Jim.ME IIRC the roll-pins item 18 in 3rd photo that hold lever rod to rockers aren't very easy to R&R. I wouldn't attempt to replace o-rings item 2nd photo on rods unless leak was very bad.

 

[RonaldK]

Thanks to both of you.

 

[trackrat]

they are giving you very good advice

 

[RonaldK]

I finally obtained the suggested parts and removed the top of the control valve. According to the parts schematic, there is a round washer at the top of the cover. When I opened the cover, I didn’t see a round washer. There was a shaped washer that fit into the inside of the cover. Where does the round washer go?

 

[buickanddeere]

I marked up a several pictures form the pars catalog. The picture of the two valves is from a 2355 parts catalog as I didn't see the dual valve setup in the 2940 catalog. From working on several of these I believe the internal seals between the bodies are the same, rebuilding uses the same seal kit. The 2355 uses different top covers ported for return oil, yours returns from the side of the valve closest to the rockshaft cover directly into the rock shaft cover, so your top covers are not ported.

Tx Jim may say different, but I am going to say unless you really want to learn about JD SCV valves and how to adjust them, do not try to change the O-rings for the lever shafts. It is easy enough to separate the two valve bodies and replace the two R26149 packing seals that are between them. Changing the top cover R49187 washers is not a bad job either. Beyond that you want the correct JD manual for your tractor, the special tool they have to hold the poppets for adjusting, a dial indicator set up and a lot of patience. Take pictures and track where every valve, spring, bushing, etc. goes so they return to the same holes.

View attachment 130654 View attachment 130656 View attachment 130657

If the SCV’s are used to operate a loader , hydraulic orbit motor , backhoe or other high flow load . You will be shocked with the increased flow , lower oil temps , reduced hydraulic “ noise” and elimination of cavitation at the front pump .
If this oil return kit is installed .
Lots of operators attempt to make do with out it but they have no idea what the tractor is missing . The transmission oil pump can not keep up with demand . Particularly in older tractors with increased internal seal seepage .

 

[RonaldK]

The leak is coming from the top plate. I am getting good pressure. Should I just replace the top plate washers? Also just where is the AR 49187 go?

 

[buickanddeere]

The leak is coming from the top plate. I am getting good pressure. Should I just replace the top plate washers? Also just where is the AR 49187 go?

Instead of the SCV dumping hydraulic oil into the transmission case . The hydraulic oil is routed to a ported transmission oil filter cover. This flow in addition to the transmission pump. Keeps the front pump and oil cooler supplied with sufficient oil. What loads are connected to the SCV's ?

 

[Jim.ME]

The leak is coming from the top plate. I am getting good pressure. Should I just replace the top plate washers? Also just where is the AR 49187 go?

The AR49187 is the one seal "washer" for the top cover. It is round when it comes in the kit and you have to fit it into the shape of the groove in the cover. A few spots of heavy grease can help hold it in place during installation.

 

[RonaldK]

Thanks for the advice. The replacement appears to be a different material, so I wasn’t sure it was correct.

 

[Jim.ME]

Thanks for the advice. The replacement appears to be a different material, so I wasn’t sure it was correct.

The ones I have gotten in kits were about like the seal gasket rings with some cartridge filters. It will be softer and look a bit different than the old one that has been heat hardened over the years.