<VV> Temporary loss of brakes when in reverse

[Frank DuVal]

When the brake pedal goes to the floor with a light touch of the foot but it works fine with harder application,  it means the master cylinder needs rebuild/replace. 

This is for both single port and dual port master cylinders. 

Frank DuVal. 

> On Aug 24, 2026, at 7:33 AM, eric--- via VirtualVairs <virtualvairs at corvair.org> wrote:
> 
> I had stopped in a parking lot with my '64 coupe 95hp PG running errands.
> When I restarted the car and shifted into reverse the brake pedal went
> straight to the floor. I was able to shift into forward and not run over the
> pedestrian behind me. The brake pedal immediately regained pressure and the
> brakes worked fine on my ride home. I do have brakes in both forward and
> reverse.
> 
> I have not seen any fluid leakage on the garage floor and have been too busy
> to get it on the lift. It's a low mileage car (19K) and the PO had changed
> the brake lines when he awoke it from a 40 slumber. Still has a single
> master cylinder and it seems to be in great condition, maybe a little low on
> fluid.
> 
> Before I dig into this I'm looking for some clue as to why I had (for now) a
> one-time loss of pedal pressure. I have not driven it since getting it home
> that day.
> 
> 
> 
> Eric
> 
> 
> 
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