Author Topic: Gasket Maker  (Read 468 times)


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Gasket Maker
« on: December 13, 2019, 17:24:09 »
I have a question on the use of sealants and gasket maker.  An example is the two access plates on the side of the block that reveal the coolant chamber, cylinder exteriors, etc.  One of these is the aluminum piece that holds the pivot for the accelerator linkage.  Both have a paper gasket between the plate and the mating surface of the block.

Do you use a sealant between the gasket and the block, and between the gasket and the plate?  Seems like a lot but maybe not?  I certainly don't want to find out once assembled that I have a leak (even a trickle) there.

This scenario will repeat itself in several other places so I wanted to check with those who also have done this.

Harry Bailey
Knoxville, TN
1966 230SL

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Re: Gasket Maker
« Reply #1 on: December 13, 2019, 19:18:20 »
There are several different ideas here and you have to look at each one separately. If your plates and castings on the block are in good shape the paper gaskets will probably be all you need. If you're unsure you can use a bit of Permatex Gray or liquid gasket sealer on both mating surfaces. I would use thread sealer on the screws or at the very minimum anti seize on the threads. Coolant comes into direct contact with the retaining screws and it can get into the threads and cause problems later on.

I always run a tap down all threaded holes in the block which will remove rust, old sealant, and any other crud that might cause you problems. If you find stripped threads in any hole repair them before assembly. Resist the temptation to undo all of the screws when some of them won't turn. 6 mm is a very small cross section and they will snap off. You will find out just how much it costs to have them removed at a machine shop. Don't try this repair on your own.
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
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Re: Gasket Maker
« Reply #2 on: December 13, 2019, 21:06:34 »
Not sure there is a right or wrong answer here and you have to take each situation for its own. Thin paper gaskets are not very strong and you would not want to use something heavy bodied as it may cause the gasket to tear while the sealant is squeezing out. My two favorites (with a thin coat) are Permatex #2 and #3 (not silicone!). #3 is thinner than the #2 adhesive and good for thin gaskets or when you have a metal to metal sealing surface such as the upper oil pan to the block.

As far as which surface to put it on: I usually shy away from putting any between the block and the gasket as it will be a pain to take the gasket off from the block in the future. Hopefully the block surface is in good shape and doesn't need any. If you put the sealant between the component and the gasket, the gasket comes off with the component and much easier to remove and clean. Plus it also keeps the gasket in a proper position while the component goes on. If both surfaces are very good, shouldn't really need any though.   

Better than off the shelf tap and dies, are Re-threading taps and dies that are meant only to clean threads. I find most taps and dies remove a small amount of good metal and make the screws or nuts a bit loose. The re- threading piece only remove damages and debris.
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Re: Gasket Maker
« Reply #3 on: December 18, 2019, 23:03:30 »
I use A Toyota product called FIPG (Formed in place gasket) It is a silicone based sealer made by Three Bond.  I use it without gaskets on the side covers.   I have never seen a Toyota leak anything so that is good enough for me.