Can anyone give me a brief on doing valve seals on a 74 240 D . Can you do one cylinder at a time with the piston at top dead center .will that hold the valves up or do you have to use air pressure?
Thanks William Rogers..........

One cylinder at a time with the piston at the top is the safest method. If you use compressed air and you were to bump a valve such that it loses it's pressure, the valve is gone.

I have replaced seals before with no effect and I've replaced them and had good results. It's just a roll of the dice.

Good luck,

Larry,

In removing the seals, do you twist them off with vice grips or some other tool? Also in installing the new ones, what tool do you use?

Thanks

Herb
'82 240D

The seals will probably be brittle and will come off easily with a straight pair of pliers. The new ones will be soft and pliable and you should be able to put them on with no trouble using a few of the ten tools that God gave you, your fingers.

Best of luck with the job,

I had good luck leveraging up on the open end of an appropriately sized wrench (an open end that fits tightly around the seal). To put it back on I pressed down using the same wrench, only this time with the closed end. The brown seals seam to snap into place, so it isn't necessary to press with the wrench, but the black ones, which have metal skirts, didn't seam to press in at all, which made me real concerned. I just pressed firmly with the wrench and hoped for the best.

On another note, ask yourself why you are doing this. I can assure you it likely isn't worth it. Even if you got plums of smoke in the morning from bad seals, I can assure you that this job is such a phenominal PITA that you will feel that it wasn't worth the major effort that you are currently facing. Leave good enough alone. This job is too much time and trouble.

Greg
'84 300D, with new valve seals!

Well, I ordered a set of seals and they arrived with the metal skirt. That was why I was asking if using a special tool to remove and install was necessary. Are there different types seals that don't have metal skirts? I don't know what kind of seals are on the car currently whether they have metal skirts or no skirts.

Herb
117,000 miles

The ones in your car likely don't have the metal skirts. My seal kit came with half of them with those skirts. It drove me crazy trying to figure out exactly which seals go with what, and no one new excactly. Do a search for my name about 2 weeks ago, and someone responded with the answer as to which color goes on which valve. I've forgotten already.

Greg

When I did my seals on my '79 300SD, the replacement seals were supposed to be two different colors representing the intake and the exhaust. The seals I was given from the dealer were updated and all black. I stared, measured, and finally called them because my manual said they were two different designs. The dealer told me that the small difference in design was irrelevant and they were now all the same.

But, back to the job itself. The Mercedes manual shows a tool that is sort of a weight with a handle with a hole in the middle to sort of tap down on the seal evenly for installation. I found using whatever blunt tools I had to evenly press them on was all that was necessary. Obviously, you don't want to damage them.

Greg S., I 'm sorry you had such a lousy time with the job. I found it to be quite simple, straight-forward, and probably the best $5.00 job I ever did to the car. It took me a couple of hours the first time I did it. Just have a nice place to set the parts you take off, so that they go back on the same spot. Organization makes it super easy. One must have is a cheap starter switch to bump the engine, I turned it by hand, but next time I'll be more prepared.