Hydraulic lifter rebuild

[NC325iC]

So while my block and head are at the machine shop I decided to rebuild my lifters.

I Did some researching and found out how to get them apart but I've hit a road block.

After smacking them on a wood block and getting the center bit out, everything I've read says the piston in the center part should just pull out easily. However it seems that there is a clip that is holding the piston in on these.

Has anyone rebuilt theirs? How did you get them apart?

[roguetoaster]

I'd imagine that they end up much like a brake caliper piston, and if you shoot some air in the right orifice it would pop out. That's not from actual experience.

Also, why rebuild when the cost of new ones is generally fairly low, especially if you go with the VW units?

[NC325iC]

Mostly because I don't know about the vw units. Please educate me.

[NC325iC]

Self educated...

Please verify if the linked part is the correct one:

https://www.fcpeuro.com/products/audi-vw-engine-camshaft-follower-050109309h

[NC325iC]

For information puroses... This is the retaining ring/clip that I'm talking about. I've already got the centers out of the larger housing. Based on what I've seen in videos and stuff I think that ring usually stays in the larger housing and the spring clip comes out of it. This allows the piston to come out (left of my pointer) easily and the internals to be cleaned properly.

However in the 9 that I've taken apart so far the ring seems to be rather securely attached to the center. I'm leaning towards using the vw units now anyway.

[roguetoaster]

I can't immediately verify the PN for the lifters, but there is/was a spec comparison out there.

Now I sort of want to take an old lifter apart just to see how it works.

[NC325iC]

https://youtu.be/ySf0r8GGMOY

pretty good video on it.

https://youtu.be/rk1a0Sx-8WM

This one is for an e36 unknown engine, when he knocks it out it kinda looks like the retaining ring just stays in the outer piece.

[NC325iC]

After looking at that second video again I'm starting to think they may just be an older design in the m42.

[NC325iC]

Update on the vw lifters (a lot of the m42club links are broken so I want to confirm the info here.)

The part number (VW - 050109309H) that I Link above is externally identical to the m42 lifters. 26mm long and 35mm diameter. The oil groove is also in the same place.

[econti]

Update on the vw lifters (a lot of the m42club links are broken so I want to confirm the info here.)

The part number (VW - 050109309H) that I Link above is externally identical to the m42 lifters. 26mm long and 35mm diameter. The oil groove is also in the same place.

Have you fit them yourself?

[NC325iC]

I will when I get the head back from the machine shop

[ForcedFirebird]

I've been using the 35mm "VW lifters" in m42's and early m50's for years (later 4v heads from BMW use 33mm) - they aren't actually "VW" lifters, the same dimensions are used in a lot of OHC heads of differing mfgr's (even the GM 3.4 DOHC). Lifters are an inexpensive wear item, not sure I would bother with "rebuilding" them.

[NC325iC]

Yeah, I was trying to do the cheapest refresh possible but that has gone out the window...