RE: Brake malfuntion

From: Ray Block (bpracing@worldnet.att.net)
Date: Sat Feb 16 2008 - 12:21:16 EST


> -----Original Message-----
> From: Azie L. Magnusson
>
> Rick B. writes: >> Well if the system were designed or worked
> as it is supposed to, it would not have happened, all I can tell
> you is, it did happen, agree or not. <<
>
> Not disputing your malfunction nor the remedy.. I just do
> not understand how it could happen that way..
>
> Azie

Well I had hoped to stay out of this but since no one else has come up with
a better explanation, I'll give it a shot.

The brake booster rod can indeed get out of adjustment and not allow the MC
piston to retract completely when you release the pedal. This will cause
some residual pressure to be applied to *all* 4 brakes. Notice I said
*all*! Why? Because there are only two lines coming out of the MC, one
for the front, one for the rear brakes. The MC piston affects both lines
so both will experience this residual pressure. From the MC these two lines
go to the proportioning valve.

The split to each wheel cylinder/caliper is *after* the proportioning valve
so they cannot be *individually* affected by the booster and master
cylinder. All four of your brakes are gonna be dragging a little....or a
lot...depending upon how out of adjustment your booster rod is.

Now for the 64,000 dollar question. Why did this problem only show up at
one wheel? Perhaps because one caliper was dragging more than the other.
There are potentially several reasons why this may happen but the one I've
experienced on mine was because lube on the adapter rails/pad ears had worn
off and that side experienced more resistance to retraction of the caliper
than the other. A little lube on those areas solved the problem. In my
case the booster itself was fine, as was the caliper piston.

In a nut shell, I believe Rascal did have a booster problem but it first
became noticeable because one caliper wasn't functioning as well as the
other.

Hope this helps.

Ray



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