[Mgs] MGB likes to lay a patch

[Max Heim]

Now that's definitely a different situation: disc brakes, and weird <g>
Citroen hydraulic fluid.

Drum brakes are designed so that the rotation of the drum causes the shoes
to tighten up, so they are predisposed to being "grabby". Discs rely purely
on line pressure and friction, so I can see how oil might just make them
slippery.


--

Max Heim
'66 MGB GHN3L76149
If you're near Mountain View, CA,
it's the primer red one with chrome wires



on 7/23/07 10:43 AM, Simon Matthews at simon.d.matthews at gmail.com wrote:

> On 7/23/07, Max Heim <max_heim at sbcglobal.net> wrote:
>> I think we're talking about two different situations.
>> 
>> If one rear wheel cylinder is leaking brake fluid, that side may be
>> contaminated as well as not receiving any braking input, causing the other
>> side to possibly pull or lock up.
>> 
>> But if instead, one side is contaminated with leaking rear axle oil, its
>> brake shoes will become "grabby" and lock up.
> 
> Could it depend on the type of brake and the type of oil? Many years
> ago, I had a Citroen which had a hydraulic fluid (mineral oil in this
> car) hose just in front of the (inboard) disk brakes. When this hose
> leaked and sprayed fluid on the rotors, the brakes did not grab, in
> fact, I lost most of the braking effect.
> 
> Also, could it be that contaminants could initially cause the brakes
> to grab, but then (as they heat up, or whatever), lose braking
> effectiveness?
> 
> Regards,
> Simon