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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: lewisnort on August 21, 2025, 08:49:14 AM

Title: Clean up gasket mating surfaces
Post by: lewisnort on August 21, 2025, 08:49:14 AM
Hi all, I'm pulling all the covers off my 98 K1100 to give them some paint as part of a complete refresh, what's the best way to clean this corrosion off the gasket mating surfaces? I obviously don't want to go too hard and I'm afraid to ruin the seal.

In terms of removing the HES so I can get the chain cover off is there anything I need to be aware of so as not to affect the timing, or even a procedure I need to follow to keep it all in check?

On a side note, is there anything I should be doing while I'm in there, already planning to check the valve clearances.

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Title: Re: Clean up gasket mating surfaces
Post by: natalena on August 21, 2025, 04:43:00 PM
Years ago I had the brick apart and ran into the same observation. Used a large piece of glass pane on the bench with White Diamond polish to "clean and true" the surfaces. Easy to do with even pressure and pre-clean with acetone and a plastic scraper.
Enjoy, Cheers
* opps, noticed it's the block side .. I'd still use a small flat glass and compound, but very careful not to spread a mess into the engine.
Title: Re: Clean up gasket mating surfaces
Post by: lewisnort on August 22, 2025, 04:49:33 AM
Thank you, the head side is much worse as I sadly found out last night so I'll order some stuff and give that a go I think.

I did see Chris Harris replace a sump pan and use a foam sanding block to very gently prep the surface but I don't think that would even scratch the surface pun intended.
Title: Re: Clean up gasket mating surfaces
Post by: Laitch on August 22, 2025, 01:19:48 PM
I don't see enough damage in your photos to warrant doing anything more than cleaning the surface with solvent, using a tan or maroon ScotchBrite abrasive pad to clean the surface, installing the gasket and bolting on the cover. If small pits have been made in the surface, a skim coat of Black RTV or Dreibond could be used as a surface sealant. Follow directions concerning curing time of that stuff before bolting up.
Title: Re: Clean up gasket mating surfaces
Post by: lewisnort on August 22, 2025, 05:01:29 PM
It was a good job I took these covers off and decided to do all this, I was turning the engine over doing the valve clearances when I noticed a washer up by the cam sprockets, I knew it came from inside due to how oily it was.
After looking around I managed to notice the retaining clip for the chain guide was missing along with it's washer.
A bit more searching and I found the clip amongst the sludge of the oil pan.
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Title: Re: Clean up gasket mating surfaces
Post by: Scott_ on August 22, 2025, 10:12:26 PM
I'll offer a bit of advice here, a torque wrench will be your best friend when putting the covers back in place.
As long as you have them already off, I would also replace the rubber grommets (11 14 1 461 475) for both the crank cover and valve cover. They definitely loose their elasticity with age, and it is the elasticity that holds the covers tight to the gaskets.
Title: Re: Clean up gasket mating surfaces
Post by: lewisnort on August 23, 2025, 03:18:46 AM
I'll offer a bit of advice here, a torque wrench will be your best friend when putting the covers back in place.

As long as you have them already off, I would also replace the rubber grommets (11 14 1 461 475)

Absolutely, I’m new to working on vehicles still so every bolt I touch is terrifying, first thing I did was buy a big and a small torque wrench, and I have a replacement for every single gasket and seal possible in the engine. If it’s coming off a replacement is going on. Also found some stainless steel bolt kits on kpartsholland I plan on using.