swkiller

iTrader: (1)

why does my tii not brake so good?? my vacum is at 15 on idle,stainless steel brake line, the car is all original tii and i have the drilled rotors, and my dads gsl-se brakes way better than my car and its bridge ported. my car stops but i really got to push that pedal hard on the floor. the brakes feel weak. oh and the pads have been replaced, the car has always felt like that since i got it. =/

Gene

iTrader: (1)

How stiff is the pedal? Is the the same with the engine on or off? Maybe something is wrong with your booster or its hookup.

Black Knight RX7 FC3S

iTrader: (7)

there is probably something wrong with your booster.
if you are stepping on the pedals while holding onto the steering wheel to keep yourself in place, booster aint working, or jammed

Go48

iTrader: (7)

The factory service manual is your friend. Download a copy free at:
http://foxed.ca/foxed/index.php?page=rx7manual

In the meantime here is the first step on how you test the booster. See page P-30 (Turbo brakes section) of the manual for more test procedures.

swkiller

iTrader: (1)

actually now that you mention it, sometimes when i brake the steering wheel tugs me to the left. like if i were to brake and let go of the steering wheel it would turn to the left. but this happens freguently but not all the time

Go48

iTrader: (7)

That could be tramlining which has to do with irregular road surface--especially at stop lights. TireRack.com has a good description. Go here:
http://www.tirerack.com/tires/tirete....jsp?techid=47

swkiller

iTrader: (1)

interesting, i read it but it doesnt say that it happens when your braking only, for me its like im going striaght and when i press the brakes it starts to push me to the left, if i let go of the brakes the car start to go straight again.

swkiller

iTrader: (1)

wow pretty nice website. i did that test, i didnt notice the brake pedal move down when i turned the car on, but it did stiffen up while i kept pressing on the pedal

bjbubble

iTrader: (2)

Sounds like a stuck caliper. Best idea is to pull both front calipers out and try to get the pistons out of the passengers side caliper (when you're pressing the brakes only the left is grabbing). If you can't budge um, try to get some reman'd calipers from napa or some other local parts house and turn your old ones in as cores. It'll much easier than trying to get them unstuck. But if they do come out easy, get a rebuild seal kit and atleast you know that's one thing to cross of the list.

ParadoxToday

Have you tried bleeding your brakes?

lonewolfrx

yeah you could try bleeding your brakes all around. Could be air in the system causing poor braking.

SoloII///M

iTrader: (13)

The four piston calipers are notorious for seizing up. Usually due to lack of maintenance (brake fluid flushes not done). Verify there aren't any seized pistons in the front calipers.

John

swkiller

iTrader: (1)

thnx for the help guys, sounds like it could be a seized piston it makes sense.

dkwasherexd

iTrader: (8)

some times it helps if you get aflat head screw driver and push the pads against the rotors, then at the same time have a buddy pump the brake pedals while the car is idling. Then turn the car off, bleed the brakes and then the pads +pistons+ rotors should be flush against each other..

StevenL5975

Hello,

sorry for bringing this thread back, but my car does the exact same thing.
Have a 86 S4 NA with vented discs f&r no ABS.

The overall braking performance is not as good as it should. At first I didnt noticed it, I guessed it was normal.
But after I got a spare car (peugeot 309) I think my 7 might have a slight braking issue.
Its not that it disturbs me but I am just wondering how this could be possible as the FC has been claimed as a car with good braking performance.
I was amazed how good that 309 stops, sometimes I lock the tires unintentionally.

It is not that the 7 does not stop as good as the other keg, the effort to push the brake pedal is much bigger.
I am almost certain that the booster is working, as I can push the pedal with engine off, and it gets hard to push after few attempts.
When the engine is running the pedal is soft as usual.

Edit:
My vented and slotted discs and pads are relatively new (+- 5000 km) they were done before I registered the car. (no idea what brand of pads)
Same goes for the calipers, rears are new ones and the front ones have been rebuild by a shop.

Thanks for any ideas.

Steven

clokker

iTrader: (2)

No one has mentioned actual brake performance...is it stopping distance you don't like or how it "feels" whilst doing so?
I've had (back when the brakes were stock) a few comments about the relatively long travel and "soft" pedal on the RX and believe that it reflects on decisions made during development- basically, some test driver liked the brakes that way.

Just a personal theory.

FCzzz

iTrader: (1)

From what I've gleaned from the way the rest of the FC has been designed, they targeted a more inexperienced driver to base their design goals on. The softer pedal feel could likely be designed in to allow drivers who don't have much real experience in feeling out the limits of braking have an easier time doing so.

SirCygnus

iTrader: (1)

clokker, im glad you responded to this thread as you are resident guru on this subject.


MAKE A MC BRACE!! i did this after swapping in my t2 clipers, and wasnt satisfied at all at the stopping power of the car. i could press it to the floor and it would crawl to a stop in a very pathetic way, but it did stop alright. but the brake booster in an OMFG WTF BBQ!! night and day. now i can lock these puppies up no problem.

or... just reaserch clokkers thread. his **** is legit.

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/holy-grail-part-deux-852021/

StevenL5975

Hi,

thanks for the answers so far.
I already have the 4 pot calipers.

My concern is that the required force to push the pedal down is too hard.
It stops well, and I can lock up the puppies even at 130 kmh if I wish to do so (ask me how I know )

From all the cars I drove the 7 has the most hard brake pedal feel.
I just dont know if this is intended by mazda or is caused by issues with the system.

Steven

Zero10

I see just one picture of a MC brace in his thread, is there another thread that outlines building your own MC brace? I am experiencing a mushy pedal without any air in the lines and a new master cylinder, but I still have the single pot fronts. I don't want to throw the money for 4-pot front brakes at it right now, but if I can make a MC brace to improve pedal feel that sounds like a worthwhile use of time.

StevenL5975

Noticed yesterday, driving my damaged 7(https://www.rx7club.com/2nd-generation-non-technical-pictures-198/suv-bumps-into-my-clean-fc-side-damage-963959/) to the shop that it doesnt stop on a driveway when pulling the handbrake to max. It slowly rolls down. lol
Had to put it in gear to stop rolling.

Is this an adjustment matter or why does the handbrake have almost 0 effect ?

Steven

arghx

iTrader: (3)

Adjust the brake booster pushrod. Unbolt the master cylinder but do not release the Lines. behind there you will see the pushrod. On the end is a 7mm nut. Hold the pushrod with some pliers/vicegrips (be careful not to damage it) and use a deep 7mm socket to lengthen the pushrod. Only a few small turns are necessary. If you lengthen it too far, the brakes will drag.

It's been a while since I've done this so I am going from memory...

here is a post a made about it a long long time ago https://www.rx7club.com/2nd-generation-specific-1986-1992-17/poor-braking-descriptive-397058/

SoloII///M

iTrader: (13)

Adjusting the MC pushrod won't change the actuation of the parking brake.

You need to tighten the cables at the parking brake lever at the rear calipers or adjust the cables at the handbrake lever.

j9fd3s

iTrader: (3)

i think our tastes have changed. my last FC is a 76,000mile car, still on mazda brake pads all the way around. its pedal is soft, but its very linear. it feels odd to me, but its actually very nice to drive

it does seem like the ideal brake pedal in 2011, is firmer, and moves less, but still linear.

it also seems like the average car has brakes that are like an on off switch because maybe it feels safer?

papiogxl

iTrader: (6)

Eliminate the power brakes and change the pedal ratio. You'll never look back.