F550 4r100, Chelsea 242/244 PTO Troubleshooting

[89Laredo]

We are working on a F550 boom truck (Im not sure on exact year, 01 maybe) with a 4r100 and a Chelsea "power shift" 242/244 PTO running an Eaton hydraulic pump.

Problem:
Little/No flow or pressure from PTO driven hydraulic pump
The flow meter shows 4gpm when pto first engages, almost instantly drops to 0. No change in engine RPM when line restriction is added, no hydraulic pressure built.

Troubleshooting steps taken:
Replaced old worn out hydraulic pump with brand new Eaton gear pump.
Tested transmission line pressure going to PTO clutch pack, found 145 PSI (Ford spec says 130).
Tested engagement solenoid is working (our 145psi was read after the solenoid)

Other info:
Noted that the engagement pressure takes almost 10 mins to bleed off from 145psi to 0, thinking it should almost instantly go to 0. Not sure if a return line is plugged or what the deal is.
Truck runs at the correct 1200 RPM with PTO engaged.

Our thoughts:
We are thinking that since the engagement pressure takes so long to bleed down the clutches in the PTO have been rubbing and are fried. Not sure how to test this theory besides taking the PTO off and tearing it apart.
Tomorrow we are going to disconnect the truck mounted hoses and run a feed/return straight into a 5 gal bucket with our pressure tester inline to see what happens, If we have good pressure and flow then it is obvious there is a restriction somewhere in the truck mounted hydraulics.

Im just looking for some other ideas/things to check while we are at it before we get into this too deep.
If someone could find a Chelsea troubleshooting guide it would be nice, I have looked and couldnt find one.

32 is the clutch pack we are thinking is fried.

Thanks,
Dylan

 

[Dogman]

Look hard at the lines first then the clutch pack. Just thought of this too has the hyd. oil been changed?? I ask is the oil could be crapped out it could be so thick it wont flow right this would give you the high psi too. With cold temps. wont help also.

Ill ask my buddy who works for a crane company if he has any book on Chelsea. But he's going to ask me for a model number. See if you can find one on that unit.

 

[89Laredo]

^ Just like the title says, its a Chelsea 242 or 244. The manuals I have found are for both, and they look to have the same internals, not sure what the difference is. Looked for a model number on it but couldnt find one, once we get it taken off we should be able to see it.

Tried the bucket test, no change. That rules out lack of supply oil/plugged lines.
Next step is take the PTO off and look at the clutch pack. Talked to a hydraulic company that sells parts for these, sounds like its not uncommon for the clutches to fry. They also said it takes 8 weeks to get the clutch packs from Mexico
My other thought is a transmission problem, but it seems to drive fine.

 

[89Laredo]

Took the PTO off, trans seems to be Ok, PTO clutch pack is badly fried.