W126 valve stem seal replacement
 

can anyone share a detailed procedure on how to replace valve stem seals on a 91 560SEL. recommended tools would be great. would appreciate it.

thx,
emmy

You may have seen this already. Will post anyway:

http://www.peachparts.com/shopforum/tech-help/48032-86-560-valve-stem-seals.html?highlight=stem

emmy, this should be what you need. Mercedes Valve Spring Compressor Kit
Benz tool number
123-589-0361-00
Let me know if you need to know where to find it.

I made my own valve spring compressor, by copying the real tool (borrowed from a MB mechanic friend). I'll try and post a pic so you can see how it was done. The shot in the other thread is clear though, so you may get some ideas to make your own too. As I remember (it's been a few years), it hooks onto the camshaft betwen the lobes (left side in pic), then you position the 'fork' (right side in pic) over the spring and push down. I used a piece of 1/4" rod for the left hook and a piece of 1/2" bent tubing for the right side, with a cut washer welded to the end to fit over the spring keeper. The lever/handle can be anything. You'll need a specially shaped hook for the end of the cam, if you need to do the valves on the ends. :)

thank you all for the responses. Since I will be doing this with the heads on, I guess i would need to use air compressor to keep the valve up. Any special tools that I need to know about? any type of air compressor that is required for the job?

thx again,
emmy

It doesn't take a lot of pressure to hold the valves up, but you will need a section of hose with a fitting that screws into the spark plug hole. Helpful to remove the fan so that access to the crank bolt is easier for turning the engine. I used 16 freezer bags labeled with cylinder numbers for my rocker arms and thrust washers so they got back in the right place. A good telescoping magnet is handy for removing and replacing the thrust washers and valve keepers. Ahh, if you are ordering parts, a few spare valve stem keepers are cheap to have around and may save an hour or two of searching for any you may drop--not that i had that experience!! Finally, the valve springs have a top and bottom, when they come off, stand them upright so they go back in the same orientation.

Egg boxes are useful too for holding 12 rockers and mating washers.

I completed replacing the valve stem seals on my 91 560 SEL a few months ago, and just went through my first oil change about 3000 miles since....I observed that there was no Oil consumed whatsoever. The solution works. Before I replaced the valve stem seals, I was burning oil at a rate of about 500-800 miles a quart.