fbse7en

I purchased my "new" FC in early Sept of this yr...a few days after buying it I noticed the following:
I like to pump/pulse my brakes when coming to a stop, gradually applying more pressure w/each pump/pulse...so as to keep brake temps down...
anyhoo, I noticed after several pumps (3+) the brake pedal would get really stiff and braking power would be reduced to almost nothing!!

It was a bit alarming when I 1st experienced it!!! I've adjusted my driving/braking style to compensate for this, but I NEED to fix this!!

The few I have talked w/think its a vacuum issue...thoughts?

gerald m

If you have power brakes it probably looses vacuum in the booster from repeated usage when braking at low rpm . .. if that is the case there are two things you can do .. Either QUIT pumping your brakes or Quit pumping your brakes .. It is also possible that the booster is getting weak .. If the engine misses when you push the brake pedal while you are sitting in park it is a indication of a vacuum leak or just low vacuum .. Try the pedal when it is not running and see if it feels the same as when the brakes fail ..

Aaron Cake

iTrader: (1)

Huh? This is improper braking technique. Just apply steady pressure to slow the car. There is almost no circumstance ever where pumping the brakes is acceptable technique.

It's good that you've adjusted you driving technique, because you are probably now using the brakes correctly.

Your issue though, sounds like a bad check valve in the booster vacuum line. Or a hole in the booster diaphragm.

fbse7en

^^ I think u are misunderstanding what I said...(i could've explained it differently too)
I'm not pumping brakes to build pressure...

I simply: apply slight pressure & release, apply slightly more press. & release, apply more press. & release...etc, etc.

^That technique has served me VERY well on ALL my previous vehicles, including an '82 Rx-7 GSL
brakes don't get nearly as hot, less strain on chassis over-all. (it worked so well on an '83 rwd ae71 'rolla that I DIDN'T wear the brakes down @ ALL in the 1st 2yrs of ownership and it was my DAILY!)

Aaron Cake

iTrader: (1)

I'm understanding perfectly. That's not how to use brakes. Just simple steady pressure is how to brake. In low traction conditions or when emergency braking, "threshold braking" is the appropriate technique.

Brakes are designed to.operate at high temperatures and may actually not provide as much braking when cool, depending on the pad compound. Pressing and releasing isn't going to do anything but reduce braking power and the more I think about it, the more unsafe it seems.

I just replaced the brakes on my daily driver after 8 years and over 250,000 KM. And I brake properly.

iday9

I'm understanding perfectly

gfucy

Seriously where did you learn that was a good idea from?

fbse7en

LMAO.

Apparently u guys aren't familiar w/some very basic driving techniques!

Cadence & progressive braking?? How about threshold?! I use all three.

http://www.drivingfast.net/car-control/braking.htm#4

http://www.ambulancedriving.com/extr...e4-pce-03.html

gerald m

These are emergency braking techniques and are not used in daily driving situations .. What the hell is the sense in aggressive braking techniques in every day driving situations where I come from if you braked like that on the street someone would be kicking a deer horn up your butt ..

fbse7en

Maybe u should read those links again, cuz they aren't just emergency techinques. I KNOW that my braking style/technique is NOT incorrect.

Aaron Cake

iTrader: (1)

OK, I thought I was crazy for not having heard of "cadence braking" before so not only did I read the two links you posted, but I also called the driving school that originally taught me how to drive. Funny story, but when we graduated they gave us all business cards and said "Call us if you have any driving questions". For 16 years that card sat in my wallet, until I called the first time ever about 15 minutes ago. And I spoke to the exact same instructor whom taught me to drive! He had already been teaching for something like 30 years 16 years ago, so he's a 46 year veteran of driver training! His response was that under no normal circumstances should this braking technique be used. Only under situations of low traction and when threshold braking cannot be maintained. Or to temporarily lock the wheels which builds up a snow dam in front of them, to aid in braking when snow is interfering with traction. Which incidentally is exactly how I was taught. Additionally, the technique can be used in times when the brakes are being overworked, such as a long mountain descent or continued high speed deceleration.

He stressed that cadence braking should never be used in regular driving because:

-it increases braking distance
-it is unpredictable to other drivers
-it can cause unpredictable handling on slippery surfaces

Here's a quote from the first link that seems to support this:

The 2nd link refers to progressive braking in an ambulance...a heavy vehicle with undersized brakes and a high center of gravity, and one in which it is paramount that braking be as smooth as possible as technicians in the back may be working to save a life.

I don't see any advantage to the way you brake vs. just downshifting and applying steady pressure as one normally would.

Anyway, it sounds as this braking technique is exhausting your brake booster of vacuum. Check the check valve in the hose between the booster and hard line. If you've just shifted into neutral and are braking to a stop, the engine won't be producing much vacuum so once you've exhausted the high vacuum in the booster, braking will be more difficult.

fbse7en

^^Cadence braking is SPECIFICALLY FOR SLIPPERY conditions! Try braking like u do in the snow & ice, guess what?! U just spun out. Once again, might wanna re-read the link.

Also progressive braking doesn't just apply to top-heavy vehicles...any vehicle w/passengers or a load that u don't want shifting around excessively, its mind boggling that people don't understand that ALL those brake techniques apply to ANY and ALL who drive ANYTHING.

air_n_water

Ok all you brake experts!
If I am stopped and pump the brakes 4 times should the pedal come up and brakes get weaker?
My brakes seem to be less powerful after the car sat for about two months during a repair. I have done all the typical service check and bleeding. I think it is the booster.