<VV> Brake Master Cylinder Question

[J R Read]

Jay,

DOT 3 or 3-4 is hygroscopic (sp?) (absorbs moisture from the air).  Water in 
the brake lines is NOT a good thing.  That rubber boot under the top of the 
MC is designed to expand to fill any void (to keep air out) should the fluid 
go low.  Fresh fluid should be added after removing the "cup" to as near 
full as you can get it without spilling any.  Put a rag below the MC to 
catch any spills since the brake fluid will eat the paint off of your trunk 
floor. Flatten the boot back out if it has been expanded when replacing it.

Now...  why did you loose fluid?  It really does not evaporate - so there is 
very likely a leak someplace.  Check for leaks in the system.  Most common 
place for leaks is probably at wheel cylinders, but could be elsewhere. 
Look at the back side of all four wheels for dampness.  Also, check the toe 
panel in the passenger compartment for dampness as well - that would 
indicate a MC leak.

Later, JR


----- Original Message ----- 
From: "Jay Pitchford" <jay.pitchford at gmail.com>
To: "Virtual Vairs" <virtualvairs at corvair.org>
Sent: Friday, May 11, 2012 8:53 AM
Subject: <VV> Brake Master Cylinder Question


> The master cylinder in my '65 Corsa convertible appears to be low on
> fluid. I've purchased Valvoline synthetic DOT 3-4 brake fluid to add
> some. My question is, do I add the fluid directly into the rubber cup
> that's located inside the master cylinder, or do I lift it out and add
> underneath? How much should fluid be in the master cylinder? Do I fill
> it to the top?
>
> Jay Pitchford
> _______________________________________________
> This message was sent by the VirtualVairs mailing list, all copyrights are 
> the property
> of the writer, please attribute properly. For help, 
> mailto:vv-help at corvair.org
> This list sponsored by the Corvair Society of America, 
> http://www.corvair.org/
> Post messages to: VirtualVairs at corvair.org
> Change your options: 
> http://www.vv.corvair.org/mailman/options/virtualvairs
> _______________________________________________