TPH seals

[Hooked_on_HP]

After plowing snow today I pulled my Ford 1900 in the garage and shut it down. As I got off I noticed the TPH dropping quickly. It always did go down slowly after I shut it off. When it got with in a foot of the floor it slowed back to normal. I fired it back up and the TPH raised right up and when I shut it off it droped quickly again to the same spot and slowed down. After further investigation I also found that if the TPH is all the way up and I raise the FEL the TPH will drop. I am thinking it is the seal on the lift cyl. for the TPH, but I dont understand why it slows down at the same position all the time if the seal is bad. The hyd. sys. goes fron the pump to the FEL out the PB port to the TPH.

 

[Soundguy]

The bore in the hyd cyl may be scratched or 'wide' farther outh near the mouth.. thus when the oring is out and the lift is up.. it bypasses.. as the lift drops the oring moves to an area of the bore that is not bad and the bypassing slows down.

That's a guess.. but I've seen it on older fords.. etc.

Soundguy

 

[Hooked_on_HP]

Is there any thing in the control valve that could cause this or would that let it fall all the way down without slowing.

 

[Soundguy]

Assuming you leave the control valve where it is.. i would think that if the valve is leaking, then it would let the cyl leak all the way down.. not just to a certain point.. etc. As i said.. a partial leakdown sounds like a cyl wher ethe tolerance at the mouth is loose, and or scratched...

soundguy