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MG Midget and Sprite Technical - Started but leaks

Although I got the '71 midget 1275 running yesterday the cloud surrounding that silver lining is leaks...

Rocker cover and heater valve leak oil and water respectively but shouldn't be too hard to fix - again: are there tricks?

Rear crankshaft oil seal is probably gnarlier. Can I get at it without taking the engine out? Is there something I need to know about fitting those neoprene seals beyond Mr. Haynes advice?

Simon Fryer

rocker cover - use a composite gasket NOT a cork one, and don't overtighten the 2 bolts, IIRC it's a very low torque setting.
David Smith

if you put anykind of gasket treatment on the valve cover gasket, only put it between the gasket and the cover, leave the bottom dry and only tighten to the correct spec, or it will "squish" out sideways when you tighten it down. This place makes a good silicone reusable gasket for out cars:
worth the price, the gasket is more compressible/flexible so it is better at filling in any unevenness in the sealing surface.

for the heater valve, it's just a paper gasket so stick it really well to the valve first. (i like to stuck it with permatex (gasket goo) to the bottom of the valve, and leave it sitting on a flat surface (like a table) for a good while, so that side has time to cure somewhat, and then add a little permatex to the bottom side and install to the engine, torque to spec. this wayi feel like both sides get a good chance to seal. Don't run then engine until this has had time to cure.

of course for both of these seals you need to be sure the top of the cylinder head is really clean, no old gasket material stuck on, etc.

rear crankshaft seal is more of a bear... engine out job i'm afraid. before you do that, however, check that the crankcase vacuum is right (not sure if 1970 used the breatehr on the front timing cover running to the carbs as later cars did, or a PCV valve set up, but if there isn't a slight vacuum on the crankcase it will push out oil from the cranshaft seals.
Chris Edwards

on the valve cover with a cork gasket Ii used silicon on the gasket to valve cover and used white lithium grease on the cork to cly does a nice job sealing and makes the cork gasket re-useable without having to remove from the valve cover

if you do pull the engine, make certian you pull the gause out of the oil seperator on the timing cover and clean in acetone or replace with a kitchen scoure pad (chore boy makes a good stainless steel one)...I was shocked how clogged and nastyied out mine was, certianly wasnt working as intended.


Thanks everyone - great help!

Chris - I don't have the breather connected up so will do that and see if it makes a difference. Really don't want to pull the engine again...
Simon Fryer

that will make a big differance when you hook up the evac hose


This thread was discussed on 27/07/2010

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