[Mgs] Brake Master Cylinder

Craig Straub craigstraub at sbcglobal.net
Wed Dec 23 15:34:29 MST 2009


This is a 1973 dual master cylinder that I purchased new a couple of years 
ago and has the plastic tank reservior.

It is not leaking at the rear connection.  Can only assume that it is 
leaking at the tank area.

Are the "O" rings standard where I can just go to the autoparts store and 
get new and what size are they?

Finally getting around to getting the car running after 6 years of sitting.

I have had the car since brand new and have upgraded the engine with Mikuni 
side draft carb, Pace headers, an upgraded cam, and 30 over pistons.

This is the cheapest solution I have.  I had been looking at Lotus Elise's 
but they are not cheap and I really cannot get my 6'3" body into one plus my 
sir arthur really acts up also when trying to get into one.  .

Oh by the way my race car is a Lotus Super 7.  Getting in is like slipping 
on a pair of shoes.

Craig


----- Original Message ----- 
From: "Hans Duinhoven" <h.duinhoven at planet.nl>
To: "Paul Hunt" <paul.hunt1 at blueyonder.co.uk>; "Craig Straub" 
<craigstraub at sbcglobal.net>; <>
Sent: Wednesday, December 23, 2009 12:26 PM
Subject: Re: [Mgs] Brake Master Cylinder


> Is the reservoir tight fit?
> Between the reservoir and the MC cyl are two O-rings.
> If the leaking fluid comes from under the reservoir, it maybe, that the 
> rings are missing or faulty.
> Better check this out.
> I assume it is regarding the dual tandem US spec. MC, which was used from 
> 1969 till some 1974.
>
> Cheers,
>
> Hans
>
> P.S. Merry Christmas list!
>
> ----- Original Message ----- 
> From: "Paul Hunt" <paul.hunt1 at blueyonder.co.uk>
> To: "Craig Straub" <craigstraub at sbcglobal.net>; <mgs at autox.team.net>
> Sent: Wednesday, December 23, 2009 10:01 AM
> Subject: Re: [Mgs] Brake Master Cylinder
>
>
>> Leaks from where?  The banjo union?  If so reseal it.  The other end of 
>> the cylinder where the push-rod goes in?  If so try pumping the pedal up 
>> and down as fast as you can for as long as you can, which should soften 
>> up the seals, if the weather is cold try warming up the cylinder first 
>> with a hair drier or fan heater.  New cylinders and long layups with no 
>> fluid can allow seals to dry out, harden and leak back when refilled.  A 
>> pal putting his car back on the road after a couple of years had the main 
>> seal weeping (gears intermittently graunching and baulking) until he 
>> tried this, which very fortuitously was a tip published in that months 
>> issue of the MGOC magazine.
>>
>> If it's leaking from anywhere else then it may be no good, although if 
>> it's from between the reservoir and the cylinder you *may* be able to 
>> solder it. I've had the reservoir corroded through in the past, but I 
>> hardly think that is the cause on a new one.
>>
>> PaulH.
>>
>> ----- Original Message ----- 
>>>I just put on a brand new brake master cylinder on my 1973 MGB.  I have 
>>>had it on the shelf for the last two years.
>>> The problem I have is that the master cylinder leaks.


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