Keystone Mod VW ALH VE TDI Injection Pump pressure relief valve 

For some reason not many have. Matt Whitbread started this years ago. It holds your case pressure control valve together so you can maintain case pressure. Over time the valve just falls apart and of course won't work correctly at that point.

Hi, are you apart the the vw tdi owners group on FB? There is a couple sources on there.

MK4mo TDI yes sir I am and I bought 4 keystones

The valve will tend to do it again.

No. It just goes in all the way.

I'm back. See you in 4 more years.

It goes spring, cylinder, retainer clip then key stone.

Doubt it.

Not enough to notice

There are a few guys in TDIclub.com and FB groups like TDI owners.

I'm not sure what size the retaining clip is.