[Spridgets] Brake Master Cylinder

[Gerard Chateauvieux]

That's actually incorrect Glen.

A residual valve should not be used with disc brakes. There is a  
different valve used with the disc brake kits.

see: http://brakecylinder.com/images/LockheedSprings.jpg

The plastic valve on the right are the ones that should be used. This  
is more of a "retarding valve" rather than a residual valve. The  
metal cup style on the left needs to have the rubber insert left out.  
I suppose your hole in the rubber cup could serve the same purpose,  
but I would be concerned that before long, that hole will become  
easily obstructed with debris.

In addition, it is also necessary to do something different when  
using the disc brake conversion on the Morris Minor. Separate  
external residual valves should be used for front and rear because of  
the position of the master cylinder. With the master cylinder being  
lower than the calipers, you need to prevent fluid drain-back by  
using a 2 lb residual valve in the main line to the front branch. I  
use a 10lb residual valve to the rear drums.

Gerard

> Message: 6
> Date: Wed, 18 Feb 2009 08:52:59 -0800
> From: "Glen Byrns" <grbyrns at ucdavis.edu>
> Subject: Re: [Spridgets] Brake Master Cylinder
> To: "Spridgets" <spridgets at autox.team.net>
> Message-ID: <FF568384924E4C56AE1B2FFD9DAB8E31 at vgl.cvg.ucdavis.edu>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
> 	reply-type=original
>
> Its for retaining a bit of residual pressure so the brake shoe return
> springs don't fully retract the shoes causing you to have to pump  
> up to get
> brake action each time.  Its also helps for solo bleeding.   
> HOWEVER!!! It
> has less function in a disc brake car and will cause the front  
> discs to
> constantly rub a bit too much and wear out the pads pretty fast.   
> Disc brake
> conversions require you to punch a small hole in the rubber cup to  
> mitigate
> the effect.
>
> Glen