The Haynes manual says sealant, but the instructions on the Lasco box say "Don't use any liquid sealant"

My experience so far with Mercedes is that besides the differential, none of the gaskets I have replaced with OEM replacements needed sealant, even in places that would on other cars (like the T-stat)

What's the consensus on here?

Thanks!
zeke

__________________

Current Mercedes
1979 maple yellow 240D 4-speed

Gone and fondly remembered:
1980 orient red 240D 4-speed

Gone and NOT fondly remembered:
1982 Chna Blue 300TD

Other car in the stable:
2013 VW Jetta Sportwagen TDI / 6-speed MT

No sealant is needed, according to everything I've read (here and in the FSM).

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

I did a 240D water pump a couple weeks back. I DID use Blue RTV sealant.

No leaks...

Good Luck, it's an easy job...

-GH

__________________
For Now:
1992 Mercedes Benz 500SL
1998 BMW 528i
2003 Honda Element
2002 CBR600F4i
1977 Coachmen Motor Home

Generally,the Mercedes parts are so finely machined that no sealant is used.
The problem in using sealants is the possibility of some "Squeezing Out" of the
interface between the gasket and the "Parting Surface"...To lodge at some
very inconvenient later date in one of the myriad of tiny cooling passages.
Then you proceed to have a very bad day.

I might ,IF I were VERY Paranoid about leaks,BARELY dampen the very center
of the gasket material on both sides (The width of the tip of a toothpick...so
that ANY squeezing wouldn't allow the sealant to escape the confines of the
gasket materiel)
[AND allow the sealant to "Set UP" per the manufacturer's instructions,before installing]

(I once installed a new H2O pump on the block of the SD with no gasket or
sealant [Do Not Ask]...and it never leaked!)

__________________
'84 300SD sold
124.128

The only place on the engine sealant should be used is the upper oil pan mating surface.

If you want to use sealant don't gob it on there with a thick bead, a light surface smear is more than enough. If it oozes out when its clamped down you used too much.

Thanks everyone. That is what I suspected - seemed odd that MB would require sealant there, but not most anywhere else.

Not so sure about the easy part....I have 2 of the 4 belts off - compressor belt is still on, I still have to spin the engine to line up the little slot with the bottom pump housing bolt, then take off the PS belt and compressor belt and figure out how the main pulley comes off.

Then remove the old pump and clean the engine all up to prep for replacement - THEN I think it will be easy

__________________

Current Mercedes
1979 maple yellow 240D 4-speed

Gone and fondly remembered:
1980 orient red 240D 4-speed

Gone and NOT fondly remembered:
1982 Chna Blue 300TD

Other car in the stable:
2013 VW Jetta Sportwagen TDI / 6-speed MT

I have the waterpump and water pump housing off the engine now, but I can't get the water pump out of the housing. I can see the old gasket all the way around, and I have tried running a blade aound the edge, wiggling, and tapping it (lightly) with a hammer, but it won't budge!

Any idea about separating them?

thanks!
zeke

__________________

Current Mercedes
1979 maple yellow 240D 4-speed

Gone and fondly remembered:
1980 orient red 240D 4-speed

Gone and NOT fondly remembered:
1982 Chna Blue 300TD

Other car in the stable:
2013 VW Jetta Sportwagen TDI / 6-speed MT

I used a 1 pound rubber mallet. Couple good whacks with that bad boy and it fell right off in my hands. These things can be hard to get off, especially if they have been there for 30 years If you don't have a rubber mallet, you should invest in one right away...

Make sure you have all 5 bolts out before you start whacking...

Are you doing the TD or the 240D? The 240D I did only required removal of 1 belt, that belt went around the main, drove the water pump, and also the alternator.

-GH

__________________
For Now:
1992 Mercedes Benz 500SL
1998 BMW 528i
2003 Honda Element
2002 CBR600F4i
1977 Coachmen Motor Home

yeah! VERIFY you have ALL the bolts out before you start whacking... a new putty knife is a fine tool to tap in there if you can't get it loose with the mallet.
just be patient. whack and wiggle back and forth. make sure it budges slightly before you try really whacking it. get a good light in there and be REALLY REALLY REALLY sure you have all the bolts out!
and, I would not use any sealant. in the old days I used to use weatherstrip adhesive (basically yellow rubber cement) on the waterpump side of the gasket and a VERY light coating of wheel bearing grease on the block side.
made removal the next time a snap! and I never had a single leak.

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Thanks, I will go out and try to get a rubber mallet tonight (& a new putty knife if I can't find one around).



I am doing the TD. I got it out by removing the alternator/water pump belt, and the PS belt. I probably could have done it with the PS belt still on, but it did give me more clearance. Anyway the PS belt was loose when I started, 'cause I had to tighten the PS belt to turn the motor enough to get the little groove aligned with the bottom housing bolt. Once I got the mechanism figured out, it was pretty easy to take the belt off for the extra room. I left the AC compressor belt on.

__________________

Current Mercedes
1979 maple yellow 240D 4-speed

Gone and fondly remembered:
1980 orient red 240D 4-speed

Gone and NOT fondly remembered:
1982 Chna Blue 300TD

Other car in the stable:
2013 VW Jetta Sportwagen TDI / 6-speed MT

This late on a Sunday, Walmart may be your only choice...

Let us know how it goes...

-GH

__________________
For Now:
1992 Mercedes Benz 500SL
1998 BMW 528i
2003 Honda Element
2002 CBR600F4i
1977 Coachmen Motor Home

A piece of pine like 2"x 2" and a foot long or so, is great for transferring the whack from any kind of hammer. you can use a carpenters claw hammer on the wood with the other end of the wood on the pump housing. Work it from all sides not just from one direction.
You want soft wood which will crush. Even a cutoff of an oak broom handle would be ok, but dont use the rounded end. it will slip too easily. Be prepared to clean the wood splinters out of the work area around the engine.

Ok, I got the rubber mallet -- $3 at Wally world. Probably going to call it for the night. I'll work on it tomorrow and report back. I can't refill the system 'till Tuesday anyway. The only place I can find around here that has Zerex G-05 is PepBoys, and they are out of stock until they get a new shipment in (Tues).

__________________

Current Mercedes
1979 maple yellow 240D 4-speed

Gone and fondly remembered:
1980 orient red 240D 4-speed

Gone and NOT fondly remembered:
1982 Chna Blue 300TD

Other car in the stable:
2013 VW Jetta Sportwagen TDI / 6-speed MT

Put something to protect the radiator core in case the pump pops off; thin piece of plywood or heavy cardboard.

For those who want to use some sort of gasket sealant if only to glue the gasket in place and not worry about it oozing into places you do not want it to go. There is an old school type product called Gasket Chinch. It is a thin rubber cement. Put it on (with the applicator that come with it) on the gasket on the part too if you want it to stick together. let both dry stick the gasket to the part.
You can also coat both sides of a paper gasket; hang it on a wire and let it dry. It absorbs into the paper end you end up with a rubberized paper gasket.
Ounce it is dried there is nothing to ooze anywhere.

__________________
84 300D, 82 Volvo 244Gl Diesel

I think we are passed that stage: