Re: Brakes - Why You Should Do Preventative Maintenance

[tobyp@xxxx]

Rich - This brings to mind a theory that I have heard, and fully 
agree with, about this phenomenon where the master cylinder goes bad 
shortly after a flush and bleed job. For virtually the entire 
service life of the brake master cylinder, it goes through about 
half of it's available stroke. At the halfway point, the pedal 
gets "hard" when the pads contact the rotors and push back on the 
hydraulics. Over the course of time, the rubber cups in the master 
cylinder wear a little away from the cylinder bore, and create a 
slight ridge at the end of the normal stroke. Then, when an owner 
decides to do the right thing, and flush the system, the normal 
method is to "pump and hold" for the flush and bleed process. This 
runs the piston inside of the cylinder through the entire stroke, 
and over the ridge half way down the bore. That is where the rubber 
cups get damaged, and begin to leak soon afterward. The solution to 
all of this is to use one of the pressure bleeders to flush and 
bleed the entire system without running the master through an 
unusually long stroke by going through the "pump and hold". I plan 
to carry the pressure bleeders soon, at DPNW. The other vendors do 
the same thing, and I would highly recommend that every serious 
DeLorean owner invest in one of them.

Toby Peterson VIN 2248 (Winged1)
DeLorean Parts Northwest, LLC
www.delorean-parts.com 


--- In dmcnews@xxxxxxxxxxxxxxx, "d_rex_2002" <rich@xxxx> wrote:
> Keep in mind if you do replace brake fluid that has not been 
replaced
> for a long time, you may end up having to change most if not all 
the
> system pieces within a few months since the older parts become the
> weak link in the system and tend to leak with new fluid installed.
> An example is changing a clutch slave and not the clutch master, 
even
> though the parts are the same age and the master may seem ok now.
> Almost every time, the master starts to leak the new fluid within 
a few
> hundred to a few thousand miles, almost like clock-work.
>