RX7Club.com - Mazda RX7 Forum

RX7Club.com - Mazda RX7 Forum (https://www.rx7club.com/)
-   2nd Generation Specific (1986-1992) (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/)
-   -   How do you check a brake booster? having serious problems no one can solve (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/how-do-you-check-brake-booster-having-serious-problems-no-one-can-solve-195446/)

ItsNiceToBurnRice 06-11-03 07:33 PM

How do you check a brake booster? having serious problems no one can solve
 
new pads, new rotors, ok calipers, new master cylinder. Pedal wasnt holding any pressure at all straight to the floor no matter how many times its pumped. I took off the MC to look at the brake booster, I had my Dad push the brake while I pushed on the brake booster rod with a hammer to see if it could move me and it could. Im guessing its not blown? Everyone keeps telling me to bleed it better, but come on. It hasnt any pressure at all, bleeding the brakes cant perform that kind of miracle.

ViperKillerWannabe 06-11-03 07:35 PM

Are you sure you're bleeding it correctly?

jaw bizzaw 06-11-03 07:38 PM

when i had my crx i had to replace the brake booster. if i remember right if its just as hard to push the pedal down when the car is off as when it is on, you blew it. the internals are very weak and can have a hole put ito it if miss treated.

jaw bizzaw 06-11-03 07:41 PM

viperkiller is right too, if you dont bleed your brakes correctly it will just make it worst.

ItsNiceToBurnRice 06-11-03 07:42 PM

Im not sure i bleeded it correctly, i was just testing the MC before i went through all the damn work of properly bleeding it. I think just because it isnt bled properly I should still be able to stop, no matter how many times I pump my brakes at a literal 5 mph roll it wont stop, I have to fred flintstone it with my foot.

ViperKillerWannabe 06-11-03 07:45 PM

Bleeding your brakes is a lot cheaper than a new master cylinder. DO IT!!!!

Amur_ 06-11-03 08:02 PM

Remanufactured MCs are pretty cheap... Remember to bench bleed b4 installation.

Icemark 06-11-03 08:27 PM

if the pedal is going to the floor no matter what it is a leak or air in the system or a bad MC, not a booster.

Boosters only allow you to increase the pedal pressure. They don't effect travel.

HAILERS 06-11-03 09:26 PM

***Boosters only allow you to increase the pedal pressure. They don't effect
travel.***

Tripple dittos to the above. The brake system you have is not bleed properly. Your compressing air right now. Booster is plenty fine good. A bad booster would give you a rock hard pedal if the rest of the system was bled good.....i.e. no brake assistance.

rotary>piston 06-11-03 09:39 PM

A brake booster wouldn't make the brake go to the floor uselessly, it's either a bad master cylinder or air in the lines. I think it's just air, actually I'm almost sure. When master cylinders go out you can still stop, it's just when you do, the pedal will slowly sink to the floor, like when waiting at a light, or if you are braking for a long period of time.
In any case, bleed the brakes like hell before replacing the MC. A bootle of brake fluid is much cheaper than a new MC. Remember to start with the wheel that is farthest away from the MC, then work your way in.
Oh, a little hint: put a clear plastic tube on the end of the bleeder screw, it's much easier to see air bubbles if you do that.

BobbyRX 06-11-03 09:50 PM

The easiest way to bleed your brakes is:

1) crack the bleeder on the passenger rear.
2) Put your index finger over the opening and have your dad pump the brakes Slowly.

This will act like a "quick bleeder", one way valve and will not let the air back into the system.
3) Check your resivor to make sure it is not running low, you have to start all over if you suck air.

3a) When you get consistant fluid with no bubbles or air, snug the bleeder.
4) Pump brakes to move bubbles in the system and ensure brake fluid is getting to the calipers.

5) REPEAT on remaining wheels.

For best results get one of those cheapy "one man brake bleeder" kits so you can view the fluid in the clear tube. When you don't have any dirty fluid or bubbles you know your brakes are well bled.

Good luck,
-Bobby
P.S. had to do this just last week. If you have the dual bleeder calipers be sure to do the lower one before bleeding the upper. Use plenty of fresh new fluid.

Felix Wankel 06-11-03 10:07 PM

Bench bleed the master first since it is new, or doing all the stuff posted above won't work.


All times are GMT -5. The time now is 01:11 AM.


© 2024 MH Sub I, LLC dba Internet Brands