Soft pedal C2 65 single cylinder

[Jerry G.]

I went to a grat event this weekend. VETTES ON THE ROCKIES about 500 plus Corvettes showen and shinen in the little town of Frisco next to Breckenridge. I was worried about hot starting and idle with my FI car. I posted questions about Reid vapor pressure and after some thought found a local racing fuel supplier that had 100 Octane gasoline that had a much higher set of boiling points than normal fuel 256 vs 198. It solved the hot start and idle stability problem. All you FI guys I think this is the answer.
Anyway, the thing I was worried about wasn't the problem. When I got up in the morning , it was about 40 degrees, I was worried about a cold atart. No problem, started and idled beutiful. The problem came when I put the brakes on as I was leaving the parking lot. No pedal !!!!!. I pumped it like crazy and it finnaly got enough pedal to stop the car. For the rest of the day the pedal was a little soft but worked fine. I got it home and it sat all night, as I went out to take it this morning the pedal was again very soft. I pumped it up and it stayed fine. I don't see any brake fluid leaking , although I haven't inspected in detail. The fluid level in the master cylinder is right up there. What the heck is going on! Is it general air in the system or a problem with the master cylinder. Any ideas or tests to narrow the problem down? Jerry

[Tracy C.]

Re: Soft pedal C2 65 single cylinder

Sounds like a master cylinder problem Jerry. Elevation alone has no effect on braking.

If a wheel cylinder was a problem, you would see leakage at the source of the problem. A collapsed line might demonstrate similar symptoms, but I've never had one to know for sure.

good luck,
tc

[Paul E. Young]

Re: Soft pedal C2 65 single cylinder

Jerry, I have found that high altitude will accentuate the problem of air in the system. I would bleed the brakes again and go to Breck for a burger to test. Try Eric's for the burger. Paul

[Roy B.]

Re: Soft pedal C2 65 single cylinder

People have had this happen using DOT4

[Jerry G.]

Re: I'm using DOT 4 (Not Silicone)

The pedal has never been rock hard, but it's also never gone away like this. If there was air at the wheels why does the pump up last for a day? Thats the part I don't understand. does DOT 4 have some unique characteristic?

[Wayne K.]

Re: I'm using DOT 4 (Not Silicone)

Jerry,

DOT-4 is not unique and is a conventional brake fluid. DOT-5 is silcone and you do not want to mix them.

Wayne

[Roy B.]

Re: I'm using DOT 4 (Not Silicone)

Wayne your right that's what I meant ! Thanks