Hein Werner WS - Release Valve Help

[ReEngineer]

Hi all, I purchased a couple of Hein Werner WS jacks some time ago and rebuilt them. The rebuild went fine, no issues. The jacks dont leak and they go up and down just fine. Here's the issue. Unless I put a plier to the release valve knob, I cant get these things to hold loads up and they slowly creep down. The model WS has a pin style release valve with some sort of seat inside the body. Is the sea replaceable? Do I need to lap the pin and the seat somehow? Or is there something I am missing. I love these old jacks. Didn't even bother painting them as the platina is great. Hoping someone can help me keep these two jacks going.

Thanks!

 

[paulsomlo]

I rebuilt a WS several years ago; from what I remember, the seat is integral to the hydraulic block and not replaceable. Seats can be lapped - you can buy lapping tools that are essentially a diamond grit embedded ball on the end of a stick. I made one using a ball bearing epoxied to a stick and used in conjunction with lapping compound. The needle itself would probably have to be cleaned up in a lathe. The subject of lapping seats has come up here before, do a little digging you'll find more info.

 

[Hiball]

I very seldom see seat issues with the needle/pin type release valves, Obviously a careful inspection can eliminate any glaring issues. The WS also using an inner piece to keep it centered, thus reduce the chance of something getting damaged. It’s a little suspect that both jacks are having similar issues, maybe a picture of the release mechanism where it screws into the block. It’s a process to get those assemblies completely seated and still operating with the square portion inside the inner threaded piece.