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MG Midget and Sprite Technical - A Series Sump Seals

I have had a leak on the Sprout, the cause was due the amount of times I have had the sump on and off in the last year, and compressed the cork strips, what so you all recommend ?

Do I go with handcut cork for the crankshaft seals, or go TAM 1089/TAM 1171 formed rubber seals ?

Ta.

Malc
Malc Gilliver

I’ve used both and they both work.

Also, ISTR seeing a shaped cork seal in the dim and distant past.
Dave O'Neill 2

Thanks Dave,

I found this - https://mg-cars.org.uk/cgi-bin/or17?runprog=mgbbs&access=&mode=archiveth&subject=97&subjectar=97&thread=200908160841148415

Some indicated positive points of view for each option, but the thread is old !


Malc Gilliver

The key to fitting cork seals successfully is not to trim them flush with the top of the sump. Leave about 4-5mm protruding each side, so everything is properly under compression as the sump is tightened. Apply a dab of sealant where the gasket meets the main caps but otherwise leave the corks dry.
Paul Walbran

Hi Paul,

I am pretty sure they were not that proud when I fitted them and tbh the sump has been on and off so many times I have probably crushed the cork to death anyway. I have bought seals from the MGOC today and will see how they go.

Thanks for the info though.

I am still happy to return your paint if you can get a return note !

Malc
Malc Gilliver

I had recollections of leaving the seal 1/16" proud, but when I checked the BMC WSM, it wasn't much help at all. (photo 1)

Haynes, on the other hand, does indeed quote 1/16" (photo 2).

I've always trimmed the seals so that the tops are level, rather than angled, as they would naturally be.




Dave O'Neill 2

I found the original cork gaskets did not need any trimming. I have just bolted it all together with a suitable sealant such as Hylomar around the caps.
Bob Beaumont

Bob

Were they straight pieces of cork, or were they shaped?
Dave O'Neill 2

Dave
They were not shaped just slightly oblong pieces. I have checked a spare unipart set and they are the same.
Bob Beaumont

Brown and Gammons due a shaped cork part
Malc Gilliver

This thread was discussed between 01/09/2025 and 04/09/2025

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