[banyan]

i am going to replace the water pump on a 560 SEL this weekend. do I need to use a silicone sealant for the pump to engine block contact surfaces? the gasket that came with the water pump looks like paper.

 

[capescor]

Maybe, you'll find the answer here. You can thank Prof Mclare by gifting him an apple, or maybe a beer

http://www.benzworld.org/forums/w126-s-se-sec-sel-sd/1446652-c126-w126-water-pump-r-r.html

 

[MrBits]

Mclare's definitive DIY writeup here may reference it, but I didn't notice at a glance. Did see this photo tho:

 

[mclare]

Yes, both mating surfaces of the gasket get coated with gray silicone WP gasket sealer.

Thanks for the kind words guys!

 

[mramay]

Don't forget that the bottom WP bolt will NOT fit past the notch in the harmonic balancer - you will have to remove the six bolts that hold the balancer to the hub.

 

[herms]

I did my water pump on my 560sel and it went smoothly with the help of Mclare's photo tutorial. You will find a water pump gasket sealer at any auto parts store specific to your job.

Take your time and remember to take of the crank pulley for that last water pump bolt. You also have to take off all the acessories to do the job (alt, power steering pump, etc.).

I stopped when the last bolt didn't come out and Mclare (by phone) was kind enough to explain to me that the crank pulley must come out to complete the job. It is a 4 hour job. I was impressed by the Mercedes belt tightening gears on all the belts, sure beats using a tire wrench!

Good luck!

 

[NordRhein]

In many cases factories do not use sealer but that is because the parts they are assembling are brand new, clean and not warped. Sealer helps make up for parts in crummy condition. DO be aware that when you bolt something down sealer can ooze out. Pieces can then break away. VERY BAD in any part of the oiling system/crankcase.