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Re: [Fwd: Oil and brake master cylinders] - NON MG

To: Paul Root <>
Subject: Re: [Fwd: Oil and brake master cylinders] - NON MG
From: Jim Evans <>
Date: Tue, 01 Oct 2002 09:51:44 -0500
Sorry to be the one to tell you this but...oil in the brake system will attack
and destroy every rubber seal in the system, including all internal seals in the
calipers, wheel cylinders, proportioning valves, master cylinder and in any
anti-lock pump & metering valves.  The amount of destruction depends upon how
much oil was added and how long ago it happened as it does take a while for the
oil to migrate throughout the braking system.  A sure sign of oil in the master
is that the rubber sealing diaphragm under the cover becomes distorted and
swollen...also, you can usually see the oil floating on top of the brake fluid
similar to an oil & vinegar salad dressing.  First thing to do is to flush the
system and replace all contaminated fluid.  Next, think seriously about 
of  the car, especially if the anti-lock components are damaged.  If the oil has
damaged any seals, there will be a loss of braking power as is common on MG's
when the hydraulic components signal a need for "rebuilding".   Rear brake 
can occur from several causes (both disc and drum) and this is one of 
vehicle should be inspected by a professional at this time.  I operated a
commercial muffler & brake shop for eight years...we saw this problem a few 
each year...usually traced to a recent oil change at a quicky-type oil change
place where the employees don't always know the difference between brake fluid
and power steering's a good idea to decline the "top off all fluids"
service at these places unless you are supervising the activity yourself.
Jim Evans

Paul Root wrote:

> Hi,
>         A friend of mine sent me this. Other than "nothing
> good", what happens. Oil isn't going to attack the rubber, but
> I'm sure it must have different compression characteristics.
>         He says that his rear brakes are locking up all the time.
> Obviously, this is DOT 3.
> Paul.
> --- Forwarded message ---
> What happens when you add oil to the brake master cylinder?  That is to
> say, if you open the master cylinder up and toss a little oil in with the
> existing brake fluid, what happens?  Someone tried to steal my truck a few
> months back and it looks like they did this little trick to me in
> frustration when they failed to start the thing.
> --
> Paul T. Root                    E/Mail:
> 600 Stinson Blvd, Fl 1S         PAG: +1 (877) 693-7155
> Minneapolis, MN  55413          WRK: +1 (612) 664-3385
> NIC:    PTR                     FAX: +1 (612) 664-4779

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