Hello all:
I am in the process of replacing my vavle stem seals. Currently I am in the stage of compressing the valve springs, but I am unable to remove the keepers. I am using a universal vavle spring compressor and I compress the springs as much as I can, but I dont know why the valve keepers dont come out.
What am I doing wrong? is it the vavle spring compressor? Thanks for all your replies!

What Mercedes chassis are you replacing the valve stem seals in. It could make a difference.

This is my 85 190E 2.3 8V.

Just to get the obvious out of the way, if you're doing this with the head on the block, are you holding the valve up with rope or compressed air in the combustion chamber?

Sixto
91 300SE
81 300SD

Use a magnet.

The keepers can deform after a lot of miles bonding them to the valve stem. You may need to take a small screwdriver and tap between the keeper and the valve to free them up. Good luck

I hope you are holding the valve up with the piston and not air pressure.

__________________
I got too many cars!! Insurance eats me alive. Dave

78 Corvette Stingray - 3k
82 242 Turbo Volvo - Manual - 270k
86 300e 5 speed manual - 210k
87 420sel - 240k
89 560sl - 78k
91 420sel - 205k
91 560sel - 85k
94 GMC Suburban - 90k
97 Harley Davidson Heritage Softail - 25k
00 GMC Silverado 1 ton 30k

Dave,

Why not air pressure? I've read on several threads that that's what folks do to keep the valves closed when changing seals.

I'm going to change the seals on my M103 soon. I was going to use air to keep the valves closed.

Sixto
91 300SE
81 300SD

Cuz then I was changing the seals on my 420sel I tried it. I put 120psi into the chamber and then tried to compress the spring (had the piston at TDC for insurance) and its a good thing I did. The keeper was wedged into the spring cap hard enough that I was able to overcome the air pressure and open the valve. If by chance the keepers had let go and the valve had opened at the same time the valve could have dropped into the cylinder. Its just not worth the risk of dropping a valve into the cylinder. Putting the piston at TDC for each cylinder only takes a minute.

Have you ever changed the seals using air pressure to hold the valves? Has anybody? I have never made it work. I tried it twice. Maybe I needed something like 175 PSI which I did not have.

Just my opinion.

__________________
I got too many cars!! Insurance eats me alive. Dave

78 Corvette Stingray - 3k
82 242 Turbo Volvo - Manual - 270k
86 300e 5 speed manual - 210k
87 420sel - 240k
89 560sl - 78k
91 420sel - 205k
91 560sel - 85k
94 GMC Suburban - 90k
97 Harley Davidson Heritage Softail - 25k
00 GMC Silverado 1 ton 30k

Gotcha. But if you don't remove the cam, the piston would have to be at TDC in any event so you can remove the rocker arm. Or at least put it back. It's good to know that 120psi won't cut it. My compressor is rated at 175psi, but maybe I'll do the rope thing.

Thanks,
Sixto
91 300SE
81 300SD

I was curious about the rope thing. How does that work? Be careful you can rotate the cam and get the rockers off and not necessarily be at TDC.

__________________
I got too many cars!! Insurance eats me alive. Dave

78 Corvette Stingray - 3k
82 242 Turbo Volvo - Manual - 270k
86 300e 5 speed manual - 210k
87 420sel - 240k
89 560sl - 78k
91 420sel - 205k
91 560sel - 85k
94 GMC Suburban - 90k
97 Harley Davidson Heritage Softail - 25k
00 GMC Silverado 1 ton 30k

From what I understand you get the piston to TDC and stuff rope into the combustion chamber through the spark plug hole. Must take some doing to get enough rope under both valves.

So you say you just let the valve drop on the piston? Can you compress the spring enough to install the keepers or do you use a magnet to hold up the valve by its stem?

Sixto
91 300SE
81 300SD

The rope trick is to get the piston an inch or so away from TDC. Then you stuff the remaining space full of a soft cotton rope (through the spark plug hole). You continue to turn the crank until you are compressing the rope into the combustion chamber and jamming the valves firmly in place.

__________________
D.H.

04 ML500
02 E430

Experience is something you don't get until just after you need it.

Thanks for the information. A new trick to add to my arsenal.

In my case the valve moved about 3/16 of an inch before hitting the piston. Then it took some good force to unseat the keepers. I didnt need anything to act as a spacer between the top of the piston and the valves. I could see how this might not work for non-interference engines.

My proceedure was as follows;

1. Remove all the spark plugs.
2. Remove all the rockers.
3. Rotate engine to TDC on the cylinder being done. Use a feeler wire in the spark plug hole to be sure of TDC.
4. Replace both seals.
5. Move to next cylinder as defined by the firing order.
6. Repeat step 3 thru 5 till done.
7. Replace as many rockers as possible.
8. Rotate the engine a little.
9. Repeat step 7 & 8 till done.

No danger of dropping a valve and easy to rotate the engine without sparkplugs.

__________________
I got too many cars!! Insurance eats me alive. Dave

78 Corvette Stingray - 3k
82 242 Turbo Volvo - Manual - 270k
86 300e 5 speed manual - 210k
87 420sel - 240k
89 560sl - 78k
91 420sel - 205k
91 560sel - 85k
94 GMC Suburban - 90k
97 Harley Davidson Heritage Softail - 25k
00 GMC Silverado 1 ton 30k

Dave,

Was this on an M103 or M116? Why not remove just the rockers for the cylinder you're working on? The engine won't stay at TDC for that cylinder otherwise?

Thanks,
Sixto
91 300SE
81 300SD