Troubleshooting no pressure at spool valve

[/pine]

Any possibility that when the work was being done that something maybe contaminated the system and has created a blockage?

Some debris broke lose or dislodged from the hoses etc??...if the disconnected hoses were left open is it possible a dirt dobber wasp blocked the end?...I have had them do that to hoses on a shelf...

 

[JDskidder]

Any possibility that when the work was being done that something maybe contaminated the system and has created a blockage?

Some debris broke lose or dislodged from the hoses etc??...if the disconnected hoses were left open is it possible a dirt dobber wasp blocked the end?...I have had them do that to hoses on a shelf...

No, I never disconnected the hoses during the time the machine sat. It had crystal clear fluid and the inside of everything looked mint when I cracked them open for the first time. I bet it's a stuck poppet like the other guy said.

 

[JDskidder]

Apparently it is a Midmark 321 from the 80s http://archive.lib.msu.edu/tic/wetrt/page/1984dec51-60.pdf

 

[Dave M7040]

Did you ever own it when it was operating properly?

You mention a re power, from what engine to the Kubota. A gas engine perhaps running at 3,600 rpm and now a diesel running much slower so nthat there is no excess flow coming out of the priority valve for steering and brakes.

Dave M7040

 

[JDskidder]

Did you ever own it when it was operating properly?

You mention a re power, from what engine to the Kubota. A gas engine perhaps running at 3,600 rpm and now a diesel running much slower so nthat there is no excess flow coming out of the priority valve for steering and brakes.

Dave M7040

No, I bought it without an engine or trencher. It had a VH4D Wisconsin so that thing was no speed demon. I think they’re rated at 2400 rpm or something like that. I put a v1505 Kubota in there and it seems to be a good match.

 

[Leejohn]

If you find out the pump is bad, I have one and well sell it. Just PM me if it turns out that way.

 

[JDskidder]

Update on this problem: The good news is that something broke free in the valve block in question during some testing and I got steering and plow function. The bad news is that just when I turned the steering to the max it hit the relief pressure and I got a small shower of fluid out of the rusted top cap. There is a piece of o-ring that's sticking out like a hernia! I am going to see if I can get away with a Prince RD-208-8 http://www.princehyd.com/mobileserv...ature?fileKey=catalogSect-ModelRD200PD0-30GPM I got a good deal on it and the original Cessna part is cast from unobtainum. Does anyone here know what the difference on the system would be in case the original valve was a priority flow control valve? It did seem to act like one from what I have read. With RPMS low I had full steering, but very slow plow moves. I had to bump up the throttle to get enough flow to move the plow at a reasonable rate.