[DeTomaso] Brake problem

[Will Kooiman]

Question:  How does the vacuum booster know to boost the brakes?

 

I was driving down the road when the engine started acting like it was under
a load.  It was pretty obvious that a brake or all 4 were dragging.  I made
it to a gas station.  All 4 wheels were noticeably overheated.  The fronts
were smoking a little.  The brake pedal didn't feel right.  It was firm
immediately whereas it normally moves an inch or two before getting firm.

 

I don't have a shuttle valve or a proportioning valve.  I have Porterfield
pads and stainless hoses, but it is otherwise stock.  I'm embarrassed to say
that I haven't even taken the calipers apart.  The master cylinder is
factory 35 years old too.

 

I loosened the brake lines coming out of the master.  A little fluid leaked
out.  I topped off the master, and it drove okay.  The pedal was back to
normal.

 

I'm also embarrassed to say that happened yesterday, but I drove my car
again today.  It's only 15-20 miles to work, so even if it locks up, it
isn't that big of a deal.  Anyway, it happened again today.

 

When it happens, I'm cruising down the interstate.  I'm not using the
brakes.

 

It is acting like the vacuum booster gets stuck and starts applying
pressure.  I realize that sounds weird, but is that possible?

 

Will.