Removing that awful black gasket?

melmaclifeform · Post by **melmaclifeform** » 20 Jun 2025, 18:13

Hey all,

Done my timing belt and water pump, and it went almost fantastically. The car runs great, timing is proper and it wasn't at all as difficult as I expected. However, the car is leaking from the water pump. When I took off the old pump that was 10+ years old, it had that black gasket which is the subject of many of RobertDIY's water pump complaints. Obviously, I thought I had scraped it off but with the leak I must have missed a spot, which doesn't shock me because what was on there seemed to be stuck on there like glue. Does anyone have any tips on how to get any remaining gasket off? Should I coat the new gasket with a layer of sealant?

The car it's for is a 2000 S70 GLT SE.

Post by **scot850** » 20 Jun 2025, 18:43

The opinions will vary as to using sealant or not. When you remove the pump check the sealing area for damage by scoring caused by the previous pump replacement possibly. I only use a very light coat of sealant purely to hold the gasket in place while fitting the water pump. I just put it on the gasket face that faces the engine block.

One thing to check is that you have the correct bolts. If they came with the pump, then in theory I'd hope they are correct. I bought an Aisin (OEM) pump that did not have bolts with it. What I found was the old bolts were too long. The newer Aisin pump has a thinner flange where you bolt it through the bolt holes. The bolts for my old pump were if I recall 25mm? long and the new pump needed shorter ones (possibly 20mm). The 2 holes if I recall to the top right of center do not go all the way through. Also the ones that do are not threaded all the way through. I wrote a note on this in a thread about 2-3 years ago when working on a 96 Volvo 850.

Neil.

melmaclifeform · Post by **melmaclifeform** » 20 Jun 2025, 19:03

Scot, I saw your thread actually before posting my inquiry. I didn't think about checking the length of the bolts, but I did order the bolts from FCP as part of a kit. If they were wrong, I would be shocked. When I pull them back out I'll check.

Do you know if there's a part number difference between the two bolts?

Post by **abscate** » 21 Jun 2025, 03:05

985151 for those bolts..see here

viewtopic.php?p=661773&hilit=Water+pump ... th#p661773

Post by **jreed** » 21 Jun 2025, 06:25

I had the same trouble cleaning off the original water pump gasket on my '97 855. I tried isopropyl alcohol and a plastic scraper, but couldn't get all the gasket material off. I ended up using a steel razor blade to scrape the metal face clean... very carefully. It's a difficult surface to access and you have to be very careful not to score / cut the sealing face if you use something like a razor blade. I took my time and was careful -- worked OK for me.
To install the new pump, I used the same method Scot850 describes above... a thin coat of RTV silicone water pump gasket maker (I used Permatex #22071, a little tube).

melmaclifeform · Post by **melmaclifeform** » 21 Jun 2025, 08:09

Abscate, it appears that I did in fact get the right bolts then as that's the part number FCP sent me. I suppose next weekend it will be time to take it back apart and see how badly I cleaned, with more plastic scrapers and some more brake clean.

Post by **foggydogg** » 21 Jun 2025, 08:26

melmaclifeform wrote: ↑21 Jun 2025, 08:09 Abscate, it appears that I did in fact get the right bolts then as that's the part number FCP sent me. I suppose next weekend it will be time to take it back apart and see how badly I cleaned, with more plastic scrapers and some more brake clean.

That procedure should work, sometimes carb cleaner can soften the old gack up too. Plastic blades are obviously preferred for the reason stated earlier.
Robert only uses Blue Box Volvo gaskets for the water pump, installed dry. My guess is he has done it a few more times than most on this Forum.

Post by **Sveedy** » 21 Jun 2025, 09:41

I use old debit/credit cards coupled with throttle body cleaner for scraping gasket material off of aluminum. You can cut them to get a fresh sharp edge or to make a weird shape.

V50M66 · Post by **V50M66** » 21 Jun 2025, 19:20

Yeah, this is exactly why you should NEVER use any gasket maker (or even an aftermarket/off brand gasket) on the water pump - it doesn't really seal great and leaves a god-awful mess for the next guy (you, in this case). Genuine Volvo gasket only, installed dry. Never had any leaks on the 10+ timing belt/water pump jobs I've done using genuine parts the specified way.

Agreed with the others - some solvent, a stiff plastic scraper, and tons of patience should do the trick. If not, you can very carefully use a razor blade on stubborn bits - just be extra cautious to avoid gouging the mating surface.

Post by **abscate** » 22 Jun 2025, 04:32

I’ll confess I’ve used Permatex , a very light film on mine. It does clean off with alcohol or brake clean like magic. The key here is a light film, thin enough thst you still see the metal. I should follow Robert-lore, though.