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MG Midget and Sprite Technical - Clutch Master Cylinder Problem

Hi Guys

This may be a very silly post / question, but the metal master cylinder for the clutch in my 79 1500 has what apeears to be a very small hole in the top of the can (on the cap plate near the folded edge). It doesn't look like rust through, it looks as though it is actually meant to be there (i.e. put in when manufactured as it looks very precise).Never noticed this before and my clutch was working fine before I had the engine out to change the clutch plate and housing, surely this is a pressurised system and there shouldn't be any hole in the master cylinder? Tried to bleed the clutch today using eezibleed and just ended up with brake fluid spurting out all over the paintwork (yikes!) and then noticed this hole.

New Master Cylinder needed?

D Williamson

That little vent hole has to be there.It will not copntinue to work if it is sealed up.

Agreed, it is there by design. As you push the pedal the fluid is squeezed down the clutch pipe. If the cylinder were sealed then you would eventually create a vacum in the resivoir and it wouldn't work properly. That make sense?

Malcolm Le Chevalier

I have seen one or two like that, but the older and much better design is to have a baffled vent in the cap. Problem being dirt & water can lie in the gutter and get in your cylinder. But, it MUST be vented.

FR Millmore

This thread was discussed on 12/07/2012

MG Midget and Sprite Technical index

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