Valve stem seal replacement ?

[deportes]

Thanks for the great response to my hex bolt removal question, I was able to use the Crafstman Bolt Out impact type that has a center 3/8" drive set up instead of a wrench, it was the difference due to clearance limit.
Great suggestion.
Now that the camshaft is out I need to keep the valves up against the head in order to keep them from falling once I try to remove the keeper from the top side witout removing the head, I have a spring compressor.
How much air pressure do I need to inject into the cylinder and does it have to be constant or can I pressure it up with a electric bicycle tire compressor and leave it hooked up at about 95 psi.
I could purchase a small air compressor if needed fom sears or so.
Need your pro advise.

[dkveuro]

With the plugs all out, rotate the engine to tdc on cylinder your replacing valve stem seals on....piston will stop valve from falling into bore.
or
Feed rope into bore with motor at bdc...rotate to tdc or untill rope squeezes
against head.
or
Use air pressure...make sure you finish that bore/valve before air runs out.
I use a shop air hose at 185 psi....with piston at bdc.
Never lost a valve yet

You will need to rap the keeper retainer to break loose the collets.
Use a socket and engineers hammer .

Compress valve spring..
Use a magnet to remove collets. Remove retainer/spring.
Pull off seal...renew seal...replace spring etc and compress to insert collets.

WARNING.....

Put clean shop clothes in any drain holes and other places that suck up small flying pieces of engine.

Do not do this job if there is any chance of interuption...ie..thunder storm...tornado...loosing air pressure...etc.



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[deportes]

Thanks DKVEURO, do I perform the following "You will need to rap the keeper retainer to break loose the collets.
Use a socket and engineers hammer ."

Before starting any compression of the spring, just to get things loosened up?

I follow your instructions, just not clear to me how to perform the step above.

[boneheaddoctor]

I've done the air hold route on two engines doing valve springs and seals...but I would change what you said...air hold should be done at TDC...and car in gear...(manual trans) or block the engine in some manner.

Why? Becasue if when using the valve spring compressor and while digging off the retainers you inadvertantly put too much pressure on the valve stem and it causes a pressure releace the valve could drop out of the head into the cylinder.....at TDC the piston stops in adn you can grab the stem and pull it back up to reseal the pressure......It saved me doing it that way several times.

[dkveuro]

Originally Posted by deportes

Thanks DKVEURO, do I perform the following "You will need to rap the keeper retainer to break loose the collets.
Use a socket and engineers hammer ."

Before starting any compression of the spring, just to get things loosened up?

I follow your instructions, just not clear to me how to perform the step above.

..............Yes.............

[dkveuro]

Originally Posted by boneheaddoctor

I've done the air hold route on two engines doing valve springs and seals...but I would change what you said...air hold should be done at TDC...and car in gear...(manual trans) or block the engine in some manner.

....................

Holding 185 psi at tdc is like playing Russian roulette with all chambers loaded.

You ain't gonna loose a valve at that pressure....



.

[boneheaddoctor]

Originally Posted by dkveuro

Holding 185 psi at tdc is like playing Russian roulette with all chambers loaded.

You ain't gonna loose a valve at that pressure....





.

I managed to do just that 3 times out of 32 valves I did that way.....so its possible.

The Car was a 5 speed stick and enfgine never budged....

it would take more creativity to block an auotmatic car.

[emmydotnet]

when I replaced the vavle stem seals on my 91 560 SEl, thesea re the steps that I followed:
1. Used a whistler to locate DTC. This method allowed me to turn the crank at the bottom rather than on top, and did not have to remove the fan, etc.
2. I did not use Air pressure. At TDC, the valve will not fall. It only have a fraction of an inch space to fall into.
3. When a cyclinder is at TDC on the left cylinder, there is a corresponding cylinder on the right that is also on TDC, so I worked on 2 cylinders per TDC setting.
4. A good spring compressor makes removing and re-installing keepers less difficult. Keepers are hard to remove and hard to re-install if your spring compressor keeps on slipping...

[deportes]

I'm having a hell of a time removing the spring, but when compressing it I am getting too much play on the valve itself. Not what I wnated but it looks like the guide is worn out on the intake side.
Now I have to look at how to continue and remove the head. What a pain in the ars.