MGB & GT Forum

Engine Side Cover Breather Plate differences?

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Sexsymbol Tim Curtis
Milwaukee, USA   USA
1980 MG MGB
Does anyone have any pictures of a newer and older Side Cover Breather Plate?

I think that I might have the wrong one on my '80 LE.

I've spent the last few days cleaning up the engine in preperation for the carb swap, engine mounts, and a timing cover gasket, and this engine was FILTHY!

Once I got past some grime it looked like the front cover - the breather - was sitting out from the engine further than the rear panel.

I pulled them both and found that the back panel uses a rubber gasket - which is what the Moss catalog says should be in place for both covers - but the front one had a cork gasket in there.

Also, the rear panel has a channel around the perimeter for the rubber gasket to seat into. The front breather cover is just a flat ridge. Since the Moss catalog says that the gaskets for the front ane back are the same part, and the rear gasket doesn't look like it would work on the front breather panel, I think that perhaps this is from an earlier engine.

It looks like this might be the cause of my oil leak.

Anyone got pictures of an early one, a late one, or both? It would be extremely helpful.



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cblankin Charles (Chip) Blankinship
Cedartown, GA, USA   USA
I tried using a rubber gasket on both the front and rear covers on my 1980. The rear cover the rubber gasket worked OK but the front cover the way it was made does not have 4 corners to hold the gasket in place. I had to use the cork gasket.

John D. Weimer Avatar
Cape Girardeau, MO, USA   USA
I have cork on both of mine, no leaks in 14 years.

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Northeast, IL, USA   USA
1970 MG MGB GT "The Bearcar"
The front cover with the breather fitted into it was fitted to my '70GT when I purchased the vehicle. It was fitted with rubber gaskets on both covers. When I rebuilt the engine I replaced both gaskets and torqued them to the required specs (I would have to look it up) and I have not had any major leaking since, about four years now. I just ever so slightly snug them every once in a great while. I believe quite a few folks get a bit over zelous when they are installing the side covers and the higher torques distort the gaskets.

Edited 1 time(s). Last edit at 2006-07-09 08:53 PM by GERONIMO.

bjack Avatar
bjack Bill Pierce
Waldorf, MD, USA   USA

I recently replaced both gaskets (that i ordered from Moss), and yes they were both rubber. I had a hell of a time getting the front one in place.

I used a gasket sealer and four pair of vise grips! I clamped the vise grips with just enough "bite" to hold the gasket in place while the sealer dried overnight, it worked.
Just be sure to clean the plate surface good so the sealer will hold.

I supposed you could use four of those large paper binder clips that can be purchased from Stapels, Office Depot or other office supply stores if you don't have that many vise grips lying around....


bassfishman Avatar
bassfishman Jeff DuPuy
Lebanon, Tennessee, USA   USA
1980 MG MGB
On my 80 I had to use a Rubber one for the rear and cork for the front. I tried to get the rubber to work on the front but it just kept leaking. It sounds like you have the proper covers for your 80.

Seabass Avatar
Seabass S K
1977 MG MGB
I am doing the exact same thing right now. My breather has leaked ever since we had the car. It has gone through all kinds of cork, rubber, and liquid sealants, not to mention a few combinations. I just pulled it off five minutes ago (which had only a cork seal) and I can clearly see the impression of the edges of the block on the gasket, and tthe metal edges on the cover are flat and smooth all around. The seal is continuous all the way around and the chimney sticking out the front is not clogged in the least bit.

And the #%$^ thing still leaks. I can wipe it clean and it will drip after five minutes. Something tells me it's not just the breather cover that is causing this (even though the rear plate does not leak). I'm going to attack the engine with a meat cleaver if I can't get the thing to stop leaking. Someone help me. America depends on it.

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JMoore Avatar
JMoore John Moore
Clifton Park, NY, USA   USA
Here's what they look like on a GF engine. It's been so long since I did mine, I can't remember, but I used cork on one and rubber on the other, that's an old John Twist tech tip. I remember I glued them onto the cover with gasket shellac let that set up and put them on the motor with a slight smear of hylomar. They've been leak free ever since. (I bet I just jinxed myself!) The 18V covers look a bit different, the rear is concave. Also remember when you put them back on not to over torque them. I believe the torque setting is 4-6ft# but check bentley. Some guys wail on them with a wrench, then they bend and will never fit properly.

John Moore

'70 MGB, '68 MGBGT, '99 Land Rover Discovery II, '61 Austin Healey Bugeye Sprite

Engine A.JPG    50.5 KB
Engine A.JPG

Engine Repaint.JPG    42.8 KB
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bassfishman Avatar
bassfishman Jeff DuPuy
Lebanon, Tennessee, USA   USA
1980 MG MGB
Do not forget the gasket on the bolt heads!!!

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