Cleaning timing cover gaskets?


Old 08-10-18, 06:15 AM
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Cleaning timing cover gaskets?

Doing a timing belt job on my Honda. Whoever did the prior timing belt job used some kind of adhesive to adhere the timing cover gasket to the engine block as opposed to inside the gasket grooves in the timing covers.

Anyway, the gasketing has plenty of oil and some grime on it from an oil leak at a couple of the seals that I'm replacing. What's the best way to clean these gaskets? Brake cleaner will clean them, but might also damage them. Maybe rubbing alcohol?

Also, some sections of the gasketing are coming loose. What's the best way to adhere these sections back to the engine block? I have Permatex UltraGrey, but not sure this will be sufficient to hold the gasketing to the block while I install the timing covers.
Old 08-10-18, 07:01 AM
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You ALWAYS want to use new gaskets.

Gaskets seal by compression, and they only compress correctly the first time.
Reusing a gasket is like trying to reuse a paper staple, you can bend it back, but it won't hold.

That's why there are "gasket goop" products out there, because used gaskets just will not seal again.
Old 08-10-18, 07:17 AM
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These are timing cover gaskets. They're only there to help prevent dust/debris from getting inside the timing cover. So gasket compression isn't really an issue here, so long as the gaskets don't leave large gaps between the block and the timing cover.
Old 08-10-18, 10:27 AM
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Most rubber gaskets are one shot gaskets and are not attached with any adhesive. You can use lighter fluid to clean the gaskets and mating surfaces.

If the slot is in the cover for the gasket..... refastening it to the block is hit or miss.
You can use that gray permatex but it won't stick to any oily surface.
Old 08-11-18, 08:31 AM
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There is no safe solvent for silicone based sealants. Dow says that strong sulphuric acid will do it....But pure Hexane will soften and swell it making it easier to scrape off. But pure Hexane is pretty bad stuff for humans. Some brake cleaners have some Hexane in them, that is why it has been recommended. I have tried Xylene and found it works ok, nasty as well but available at hardware stores, good for the final wipe down before applying a fresh sealer of some sort. Lots of ventilation and nitrile gloves required.

I advocate a sealing compound called Hylomar, the Hylomar Blue is mostly the type used for automotive. It never fully hardens, so disassembly is not the typical nightmare you get with the silicones. It is a polyester/polyurethane compound, many in the older Ferrari community use this as the cars tend to be over serviced and constantly taken apart. Fantastic stuff, easy to work with as gasket dressing, thread sealing on oil pans bolts, etc.

Hylomar also makes a solvent they claim remove silicones, not sure what is in it, I think Acetone. Never tried it, but it might also soften silicones well enough.

The Permatex gray is the same as the gold standard "Hondabond" that is used for permanent seals. Certainly works extremely well on clean surfaces, but not good for things that need periodic disassembly.

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