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MG MGA - tappet cover oil leak.

For some time I have had a persistent drip from the rear tappet cover on LH side of engine. Tried new cork gasket no improvement. Got new cover from Moss and another gasket. (Incidentally this new cover is concave shape which I had never seen before but same size. They do not offer convex type.) Engine has metal breather pipe down from front tappet cover. This is clear of obstruction. Slight oil vapour from this on start up.
Also has rubber pipe from rocker cover to front carb.
Leak with new cover so heavy now that lost about a quarter of a pint of oil in a few minutes, which makes the car undriveable. Any ideas? By the way fixing these covers back on is a swine of a job because there is very little clearance between end of bolt and exhaust manifold. I now use a narrower bolt with end sawn off as a pilot to position the cover.
H L Davy

1. Are you sure that the old cover cannot be reused. Just make sure that it is flat around the flange, and that all the old gasket is removed from the flange AND from the engine block. This is hard to do with the manifold in place.

2. There should be a cup washer and a rubber seal at the bolt. These are often forgotten

3. Over-tightening the cover makes it deform and leak

4. Glue the gasket to the cover before fitting. Then make sure that the cover is sitting squarely and is not askew before nipping up but not locking down so tight that the cover's cone is starting to deform.

If you need an original cover I have a couple lying in the graveyard box. I use two vented ones because of the Judson.
dominic clancy

Thanks quick reply Dominic. Yes I went through all the steps you mentioned 1-4. It is possible the cover was overtightened which is why I bought the new one from Moss which is actually a bit more robust. I am trying to get another cover from Morris Minor specialists as it is the same thing. Indidentally some offer neoprene gaskets rather tha cork. Anyone have experience of those?
H L Davy

Hi
The neoprene gaskets are more suited to MGB covers, some of which have a lip/shoulder around the perimiter to hold the gasket I don't think they are a good idea for the flat edged covers as the neoprene will eventually squirm it's way out
Cork is the wat to go, glue it to the plate with contact cement to hold it in place and then fit it up either greased if you want it removeable or gasket cement if not
willy
William Revit

H L Davy,
Stay with the cork gasket....as these guys suggest.

dominic clancy
Removing the gasket is hard to do with the manifold in place. Good advice and way understated imho!

Permatex sells a sealent called "The right stuff"
http://www.autozone.com/sealants-glues-adhesives-and-tape/sealant/permatex-5-oz-the-right-stuff-gasket-maker/416211_0_0/

Ive always had trouble getting the tappet covers to seal up...On One of my MGAs I made an aluminum plate cover that goes across both openings and is sealed by a gasket just as big.

I found that "The right stuff" worked just as well on those stock covers and dabbed a little on the bolts too and it worked a miracle. No more leaks from that area. Its a little pricey but was worth it.

I dont know if you can get it over there but look in to it.

Good luck and if you do find it let us know what you think! :-)
Steven Devine

Minor club guy told me that the concave plate I bought needs the rubber gasket. I fitted this with blue Hylomar and was careful not to tightn the boly too tightly. This worked. Mind you still have quite a lot of oil smoke down the breather pipe.
H L Davy

New valve guides needed?

Steve
Steve Gyles

This thread was discussed between 08/02/2015 and 17/02/2015

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