Anyone Ever Have Vacuum Brakes Fail To Perform?

[~JM~]

If so, please tell us why/how & what happened?

~JM~

 

[rmar]

If so, please tell us why/how & what happened?

~JM~

Hell, I have had hookers fail to perform.........:wink:

Anything and everything can fail. Master cylinder fail/line pop/blown seal in caliper.
What are u trying to ...............figure out?

 

[chops]

No. I have never had it fail but like rmar said hookers can fail lol as far as reliability you can sleep better at night vs the powermaster set up you will prob have 2 master cylinders fail before a braje booster!!!!!

 

[Razor]

I've had a hose pop of the booster from running 30+ psi. The car still stopped but the pedal was hard.

That was fixed with a AN fitting arrangement from Summit.

 

[TurboBuRick]

Biggest complaint is hard peddal. Too small of a booster and/or wrong size master will cause problems. The right booster and master are critical.

 

[gnmaster2004]

brakes

make sure you have good vacuum.

 

[Adam Connell]

They always stop better then the PM... ALWAYS. The big brown stains on most of the TR's front seats are from the stock PM failing... I think jumping out of an airplane is a good idea, but I'd never run a PM again, I'm not crazy.

 

[~JM~]

Just trying to collect some insight. I had originally planned to go with a Hydro-Boost system, but went with Vacuum instead. So far so good, but I've only street driven the car. What happens at high speed (120+) while under boost than jump on the brakes? Does the Booster store a certain amount of vacuum? Does simply lifting off the throttle provide enough vacuum?

Thanks
~JM~

 

[TurboBuRick]

Yes the brake booster stores vacuum charge. Most of the time your driving, it's just like a regular non turbo car. When you get into boost the check valve in the brake booster closes keeping boost out and vacuum charge in.

Have you jammed on them yet? Does the pedal get hard?

 

[Turbo6inKY]

Just trying to collect some insight. I had originally planned to go with a Hydro-Boost system, but went with Vacuum instead. So far so good, but I've only street driven the car. What happens at high speed (120+) while under boost than jump on the brakes? Does the Booster store a certain amount of vacuum? Does simply lifting off the throttle provide enough vacuum?

Thanks
~JM~

If the check valve leaks and allows boost into the booster, or if you're in a situation where you're alternating WOT and full braking (like an autocross), you could be caught with low power assist upon initial application.

Never fear, as soon as your foot comes off the gas, the car will start generating vacuum and the power assist will come back. It takes some practice, but you can learn to anticipate it, jamming on the brakes as hard as you can and then backing off as the power assist comes in to prevent lock-up and a skid.

The fix would be a higher-quality check valve, possibly an external vacuum reservoir on the booster side of the valve, Hydroboost, or just dump it and switch to full manual brakes. Get your car weighed and call Wilwood and they'll give you a master cylinder sizing recommendation.

 

[~JM~]

....Have you jammed on them yet? Does the pedal get hard?

I have not jumped on the brakes yet. The brakes work, but they're not anything to get excited about. My 3/4 ton pick-up truck has better brakes. I'm beginning to think that full manual is the best way to go for a consistent pedal & performance.

~JM~

 

[Turbo6inKY]

I have not jumped on the brakes yet. The brakes work, but they're not anything to get excited about. My 3/4 ton pick-up truck has better brakes. I'm beginning to think that full manual is the best way to go for a consistent pedal & performance.

~JM~

Don't confuse initial bite with actual performance. Good pad selection and a good bleed will do wonders for initial bite.