Change valve stem seals with the head on ...

[Ben Lessani]

Before you say it, I've read the guide on here and a few others around the net.

The trouble is, I don't own an air compressor, so I wouldn't be able to pressurise the cylinder to keep the valves in place.

So then there is two other techniques, both of which I'm a bit confused about.

The rope trick - shoving about 7/8 feet of rope into the cylinder. But how exactly does this work, to compress the valve spring you need a reasonable pressure - how can you shove enough rope into the cylinder to prevent any movement in the valve? Or do you put the rope in, then turn the crank until there is resistance?

Then the last technique, which is to turn the crank until its at TDC for the relevant cylinder you are working on. This means the valve can only drop about 2mm? So if the valve dropped, would you still be able to compress the spring enough to get the keepers in the correct location?

The last method seems the safest to me - if it works that is. Also, does anyone have a valve spring compressor and stem seal pliers I could borrow for a weekend

[Rodriguez]

Its my understandin you wind the piston up, filling the chamber with rope.

[DarnPB]

Remove the spark plugs. Rotate the engine to bottom dead centre, ie, bottom of its stroke. Feed in the rope on the cylinder in question, then carefully rotate the crank to move the piston up, but make sure you do this on its compression stroke. Continue to rotate carefully untill the engine locks up. When the engine is locked, the rope in the cylinder is pressed hard up against the valves preventing them from dropping. You can then remove the valve retaining collets and springs. If the engine is accidently turned whilst the collets are out and the valve drops, you have no option but to take the head off, so be carefull.

[Ben Lessani]

Thanks mate, clears up the confusion

Fingers crossed I won't lose a valve! Now to steal some valve tools -I can't justify buying them for what I know will be a one off job!

[Conker]

My advice... Make sure you get a mahoosive valve spring/bar to compress the valves down - I bought a fairly weedy one and it wasn't even slightly up to the job. Check it fits on the head too before you start the job.

[Ben Lessani]

My advice... Make sure you get a mahoosive valve spring/bar to compress the valves down - I bought a fairly weedy one and it wasn't even slightly up to the job. Check it fits on the head too before you start the job.

You offering one

[Conker]

My advice... Make sure you get a mahoosive valve spring/bar to compress the valves down - I bought a fairly weedy one and it wasn't even slightly up to the job. Check it fits on the head too before you start the job.

You offering one

Jog on.
 


(I haven't got one)

[sidecarphil]

i've never been inside a VW engine

BUT on another engine type i have a lot of experience with , we used a rocker and welded a tube on it so you can lean on it , pushing the valve down