Dismantling hydraulic lifter

#1
Hi all,

As part of the general cleanup and internal gunk removal from heads and valley, I've removed the lifters and are going to clean these. But, I can't get them apart? I can get the clip off and the top section which seats the pushrod, but the internal sleeve piston will not come out. I can push it a bit in, maybe .1-.3mm but it will not come out. I can't see why this is. There is no varnish or anything to prevent it coming out. I've even tried using a piece of bent brazing rod hooked in the internal hole but no, it still won't come out.

Can someone who has been successful with this let me in on the trick.

Thanks,
 
#2
Well, after trawling the interweb I came across a couple of videos of how this is done. One used a proper internal bearing puller with slide hammer, the other simply used a sleeve anchor bolt. The bolt is inserted into the internal piston, screwed up a bit and tapped out with adjustable grips behind the bolt nut.

Took a bit of tapping but it did come out. On inspection the reason the sleeve piston woul not come out is there is alot of gunk and varnish in the machined cavity between the outer body and the inner piston. I used this method before I decided it was a bit too harsh an needed to find a better method. This got me to thinking of how to remove the varnish so the piston slid out easily. Enter paint stripper. Here's my method.

1. Remove the clip and cap from the lifter. Empty oil and clean with solvent cleaner. Ensure to push down on the ball bearing valve in the bottom to clean the oil out of the bottom chamber.
2. Mix 50% paint stripper, the bad dichloromethane type, with 50% methylated spirit. This makes a nice runny solvent which with the paint stripper will eat the varnish in no time.
3. Soak the lifter in this mixture for at least a couple of hours, I leave over night. Give a bit of a stir every now and again. Also make sure to "pump" the lifter by pushing in the ball bearing valve.
4. When ready take out of the solvent and pump the lifter a few times and you will find the inner piston slides almost flush to the end of the lifter. You can then hook out the piston with a piece of bent wire.
5. Clean up in warm soapy water to remove paint stripper mix, then solvent to clean again.
6. Inspect, oil and reassemble.

The paint stripper mix removes ALL of the varnish and the lifter looks almost brand new.

WARNING: paint stripper is nasty stuff. Wear good gloves and use in a well ventilated area.

Craig
 

PeterZRH

Well-Known Member
#4
As they are only £60 a set, why bother? If fact, I don't think I've ever put back used cams, followers and timing gear as it is so cheap and so key to how smoothly an RV8 runs. If you have the engine apart. it's good to know if you do this, then you don't need to think about the top end for another 50k miles. If you put it all back together and they are noisy then that's just more work, not difficult admittedly.
 

rockdemon

Administrator
Staff member
#5
The time you'd do it is if the car has a recent cam and you need to keep the lifter case but have new innards to stop a tap...
 
#6
A method I employ to clean tappets is to soak each one individually in thinners in a glass spice jar, they're the ideal size. This also means the tappets can be kept in order if desired, only downside of course is trying to find sixteen of them.
 
#7
if I had my engine stripped enough to have lifters out..I would replace with cam and chain etc all at same time. though admittley it will removes most varnish and carbon . a lot of work!
 

clive P62

Active Member
#8
I hate to put a downer on things but if the cylinder heads / valley are coked up with carbon that normally indicates poor servicing and general lack of care. By the time its got to that state the engine is dead even though it may still run. Its requires a engine removal / full strip and a chemical clean and inspection / rebuild.
Clive.
 
Top