Dima26

I noticed some time ago that my RX-8 has "spongy" brakes. Very similar to what you would feel if the brake system has air. Let me explain in more details. If I press the brakes a little bit, the car starts decelerating and the pedal feels very soft, then as I press the pedal way further down making stop close to an emergency stop (so that is the maximum deceleration) the pedal still feels soft and I can press it further an inch or so. On my previous car (Ford Probe) the pedal was soft at the beginning but when you press it for a maximum deceleration (on the verge of blocking the tires) the pedal feels much harder after that. Or on another note, if the car is at a stop light and I press the brakes, the brakes on the Probe had a final point (in the middle roughtly) after which you cannot press them any further and the pedal is very tight. On RX-8, on the other hand, I can press the pedal after the maximum braking point (see above) when the car not moving and if I push it further, it goes further with gradually increasing resistance but it does not have a sudden stop like my Probe had (and some other cars I drove before).

So the pedal does feel like I have an air in the system. Except that pumping the pedal several times does not change anything (if I had air, it would change). Do you have something similar on your 8 or am I having some brake problems? To answer possible questions, the car has 3K on it and never had any brake-related work done. The level of the brake fluid is at max.

JonsToy

My brakes feel great, like steady pressure on a firm pedal will stop the car quickly. In my previous vehicles, the situation you experienced was the beginning of master cylinder failure. Brakes are nothing to fool around with. Have it looked at by a competent professional.

Dima26

Thanks for response. The pedal does feel like I have a problem with master cylinder or air in the system. Odd is the fact that the brake fluid is at max and does not change. I guess, this means a trip to the dealership...

mauricio

depends what pads are on it I read in some tread that mazda is using softer pads that you would have to press the pedal a lot harder but with excellent stoping power

RPIRX-8

How does the color of your brake fluid look? If the car is that new, it should be a golden color. If it is more brown looking it means the brake fluid is bad. Also, check the system for leaks. Make sure all bleeder screws are firmly tightened. If all else fails, bleed your brake system. This can be made easy with Speed Bleeders, www.speedbleeder.com.

Dima26

Thanks for recommendations. Actually I did all that and the brake fluid is golden as the sun in the morning and as clean as a raindrop. Nothing seems wrong except for the spongy feel in the brakes. No leaks, the fluid is at max level. I will go to the dealership soon (did not have a chance to go sooner) and have them take a look at it. The brake pedal feel is just a little bit strange and that's it. I thought it was the "personality" of RX-8. On my previous car the pedal was easy to push when the pedal was all the way up but then after an inch or so, you couldn't push it anymore no matter how hard you tried (does not go down at all). On RX-8 the pedal is soft at the start of the travel but I can push it down and it goes more down as I increase the push (I do push hard enough). I never noticed this before I tried. The cars stops on a dime (knock on wood). If there is an air in the system, usually you see some drop in the brake fluid level and the pedal feels ok after several pumping motions. I do not see any of these.

I will let you guys know how it will go at the dealership and whether it was normal or not.

Dima26

By the way, maybe I just cannot explain what I experience very well but I cannot understand from your responses whether you have the same feel in the pedal. Just an example:

Quote: My brakes feel great, like steady pressure on a firm pedal will stop the car quickly.

I have exactly the same on my brakes. If I put a steady pressure (just a little bit), the car will stop quickly without any problems.

Now, imagine the following experiment. You push the pedal with a given force, say 100 N, which corresponds to maximum braking and at this force the pedal moves down for an inch. If you apply stronger force, will it move down further? On my previous car, the pedal moves down at 100 N, 120 N (just for example) but the it was stopped and if you apply 500 N it does not really move anymore at all and is basically at the same level as it was at 120 N. Do you experience something like this on your car? Or the stronger force you apply the more the pedal moves down?
Could somebody check this out on his car? I would appreciate it a lot.

Explanation to a definite stop of the pedal is simple. When you start pushing the pedal, the brake pads start moving and they stop when they reach the rotors and push them strong enough. After this moment, no matter how hard you push there is no motion in the brake pads and the pedal should be very-very hard (by hard, I mean if you are a strong man and apply all your foce, the pedal does not move at all) because you are just trying to compress the fluid (incompressible) and damage the fluid lines. This is a very simplified picture not taking into account air compressor (or how it is called, sorry English is my third language). The air compressor can change this but on all my previous cars I had the same "hard" brake pedal (they were not very fancy cars.

swoope

iTrader: (5)

here you go and this was a bit of work.

bleed the master cylinder.

https://www.rx8club.com/showthread.p...ht=brake+bleed

hope this helps

beers

Dima26

Ok, guys, I have an update on my case. I took the car to the dealership for the heat recall and asked them to check out the brakes. The technician checked everything for leaks, etc and found none. Then he compared the brake pedal "feel" with two other stock RX-8 and found no difference. I sat in one of them and tried the brakes - the same spongy feel as in my car. I guess, this is just a personality of RX-8: the brakes feel soft or spongy as compared to some other cars I drove. I know, I am being too picky.

Nothing feels better than driving your beloved 8 after loaner Dodge Neon with auto

Astral

It must be the feel that you're used to. The RX-8 brakes don't feel spongy to me at all. In fact, I thought that they were a little too tight after driving the Protege brakes (which were actually a little spongy).

I drove a 2004 VW Jetta recently and that car had a really heavy pedal. Compared to the Jetta, the RX-8 has, what I would call, an effortless pedal. With the Jetta, the brake pedal felt "100 lbs heavier" (figuratively, of course). However, despite the heavy motion, the Jetta brakes felt linear: if I increased my brake pressure by 25%, it would seem to stop 25% sooner. If I increased it by 50%, it would stop 50% sooner. So the response in braking force to braking pressure felt pretty linear.

I also drove a Ford Taurus and a Ford Explorer and they had "heavy as hell" brakes that were also very non-linear feeling. It felt like you start pushing the already heavy pedal, and then it felt like you hit a brick wall. It was non-linear in that I had to give it 75% increase in pressure to get a 40-50% increase in braking. I really had to pound the pedal to get the car to stop very fast (on the verge of triggering ABS/locking tires). I really didn't like that feel (in the Ford Taurus and the Explorer).

So after I adjusted to the tighter RX-8 brakes, they have the best feel for me (I like that feel the best). They are not very heavy, tight, not much play, and linear.

Razz1

Dima, if you don't like it buy aftermarket stainless steel lines. They will make you happy.