John Deere 4200 loader slow

[DiskDoctr]

Dan,

Be sure to recheck your hydraulic fluid level. What kind of fluid did you use?

You did recheck it after starting and working all the cylinders, right?

It's the easiest thing to check

- JC

 

[Dmatt1222]

:thumbsup:My problem is solved (for now)

I rechecked the suction lines and all were in good shape with no problems found. I started tractor still no action from loader.

I checked the pressure using a setup described by KENNYD ( gauge found at harbor freight 12 bucks, hose with male QD from my log splitter and 1/2 too 1/4 bushing from hardware store) max pressure at all QDs approx 105 psi.

I then pulled off the R fender to inspect SCV. All linkage connected and properly adjusted.

I removed the only relief valve I could find. A non adjustable relief threaded into the SCV. I found no junk in the valve but I operated the valve by forcing open the relief piston with a 3/16" pin punch followed by a solvent cleaning.

After reinstalling the relief valve I rechecked the system pressure and found it to be 2050 psi. I reconnected the loader QDs and the loader worked like brand new!

I would like to thank everyone for your help in solving this mystery and saving me $$$$ I hope this thread will be of help to others with simular symptoms.

Dan

 

[arrabil]

Awesome.

 

[kennyd]

Great news Dan:thumbsup: There should be a adjustable PRV on the tranny somewhere also I think...Perhaps this would be a good time to invest in the service manual on CD?

 

[DiskDoctr]

Whoo-hooo!!!!:dance1::cool2::thumbsup:

 

[beenthere]

I'd like to pinpoint that relief valve on the schematics. Anyone with pics or more specific id of where it is located? I have the CD service manual (4200, 4300, 4400) and a page or figure id would be a big help.
Thanks, and great to hear that the problem has been fixed. Special thanks to kennyd here too.

 

[mjncad]

Kenny is the man when it comes to hydraulics!

Glad you got it working for low $$$$.

 

[Egon]

[Great news Dan:thumbsup: There should be a adjustable PRV on the tranny somewhere also I think...Perhaps this would be a good time to invest in the service manual on CD?/QUOTE]

There are two PRV's on the transmission. Neither are adjustable. The manual calls for a 10,000 psi gage for these.

They are located just to the right of the HST filter when facing forward's. There are also plug locations for attaching a gage.

 

[beenthere]

I poked around in the CD for this Deere, and found there is an adjustable valve on the SCV block (am thinking this is the one the OP found to be sticking) and have two pics showing it here. A third pic shows the placement of the two Forward/Reverse valves mentioned by Egon that are only for the tranny, not the hydraulics as being discussed (just for clarity here )

 

[kennyd]

I poked around in the CD for this Deere, and found there is an adjustable valve on the SCV block (am thinking this is the one the OP found to be sticking) and have two pics showing it here. A third pic shows the placement of the two Forward/Reverse valves mentioned by Egon that are only for the tranny, not the hydraulics as being discussed (just for clarity here )

Thanks BT, I knew there had to one that was adjustable somewhere!