4230 syncro another update (slow hydraulics) Stumped still

Ok, update with pressures, etc from my 4230 with Syncro trans and slow hydraulics, which some times affects steering as well. No chatter just slow at any rpm. See previous 4230 posts as well.

As requested tested stand by pressure and it is 2250-2300 lbs at the remotes and test port on T Block where it tees off for the steering and rear rockshaft.

When testing pressure at the T block mentioned above when using the rear remotes pressure drops from 2250 to 1700. Then pressure drops to 700 lbs and stops working. Pressure slowly will build after about 10 seconds up to 1700 again and then drop to 700 and stop.

Clutch pressure is 119 lbs at any rpm and if front pump is destroked.

Lube pressure is 2-3lbs at idle up to 20lbs at pto speed.

We have tried to get to the pressure valve under the rock shaft area as suggested but in order to get to it I have to remove the lift arm off the side of the rock shaft and its not coming loose.

JD dealer is 150 miles away and cost $600 for 30 minutes and was not help.

Another tractor shop an hour away will look at it if I get it to them. Figures its the front pump...Says they fix lots of John Deeres.

Check to see if you have a manual bypass valve in the filter relief housing. If you do have one make sure it is closed. If you are not sure about the hyd filter then put in a new one. Then make sure that the filter relief valve in the filter relief valve housing is free in its bore. Would also be a good idea to remove the suction screen and make sure it is clean. Sometimes people use the wrong oil and the screen gets plugged from the deteriorated brake material. If all this is good then shim up the press regulating valve as 119 is way too low. You will have to check the spec on that one. I would also verify that the cooler relief is free in its bore and not stuck open which would also starve the pump.

I have had the tractor 10 years, was fine till the cold snap last winter. Screen and filter are good. Filter relief is free and clean. I the trans should have 138 I believe. I don't see a manual filter relief valve.

Haven't checked the cooler relief first I have heard that mentioned.

Check the lube pressure when the pump isdestroked and compare with the lube pressure prior to destroking the pump. Should be close to the same. the spec is 3 psi. Check lube pressure when the pto is engaged, when the HI-Lo is in Hi and compare to the Lube press when in Lo. Check lube pressure with the clutch pedal up and also with it down. If you have low lube press in one as compared to the other you have a low pressure leak. causing the low lube pressure. You may also want to check the screen in the head of the main hydraulic pump and make sure it is not plugged. Also when you say that the press dropped to 700 psi it may be an indication that the pump is slow to go back into stroke. You would want to verify that the crankcase outlet valve in the pump is free in its bore and not sticking.