im not sure if all stock rx7s are like mine, but i have to step about half way on the petal before i get anything out of my brakes, the fluid is at the fill line, and im almost positive it holds pressure (tested it by pumping it with the engine off). i dug around and could not find a whole lot, and before i go ask a random guy on craigslist if i can drive his car, flush the fluid to see if it will make a difference, i thought id ask here
so the questions i have:
1. is your braking like this?
2. is there a way i can make it more responsive? (besides left foot braking)

 

FC's are really weird, the FB's always have a nice pedal, the FC, its like half really are mushy, and half are nice and firm.

the FC does have a couple of oddities that make getting a hard pedal, um hard.

1. the rear calipers have TWO bleeder screws. i'm not sure why, but they do need it.

2. when you bleed the rear, the system becomes firm enough so you can't bleed the front. i like to do the front first and then the rear.

3. check your wheel bearings, loose wheel bearings push the caliper pistons further in than "normal" and thus it takes more pedal stroke to get the same braking. if the first application takes a long stroke, and the second doesn't this is your clue.

4. aside from this there are some other clearances and checks in the FSM, for the pedal height, freeplay etc etc.

 

Recommend power bleeding rather than friend in the car pumping the pedal bleeding.

 

Bleed the brakes, check pad and rotor thickness.

 

IMO, your brakes are probably fine, the 2nd gens were developed with that brake feel.
If, like me, you don't particularly care for it, the easy fix is to swap the booster/MC for larger units.

Someone is certain to mention a 929 swap and that certainly will work.
So will multiple other donors.

 

You can also look into purchasing or making a brace for the master. The firewall likes to flex. Have a buddy mash on the brakes while you stare at it. It will move.

 

The FC firewall (and you didn't even mention the booster) don't flex nearly as much as the FD but a brace certainly wouldn't hurt anything.

 

Might wanna check the archives for a write up on the master cylinder brace.

 

Check the vacuum lines to your brake booster. If you've recently bled the brakes correctly, one of your lines is probably rotted. It's most likely the one that makes an "s" bend on the pass. side by the ACV. I recommend ordering a dealer replacement if it is bad, it's hard to get a hose to bend to that shape.

 

Replacing the brake lines will also take away a bunch of squish in the pedal. New OEM and SS lines are pretty similar in pedal firmness after replacing.

 

I recommend doing what Hozzman said. I confuse a lot of people with this, but it works.

Before doing anything, check the brake pedal free-play. You should wiggle the brake pedal and notice about 1/2" of play in it. If not, adjust the brake pedal pushrod until you get it right.

Get a mityvac. Start at the farthest wheel from the master cylinder, i.e. the right rear. Hook the mityvac up like this:

Force fluid up through the brake lines, through the master cylinder, out the reservoir. You're going to need to check the reservoir every once in a while so you don't overflow it. Once every wheel is done, check the pedal feel. If it's still spongy, you may need to bleed it at the master cylinder by cracking the lines loose while a friend holds the pedal down.

 

Yeah I did mine myself and it felt like crap after, took it to a buddies shop and had it power bled again (after my break pedal mashing attempt) and it felt much better after.

 

I have always done the brake bleeding with a partner. It works and I have never had issues with many different cars. I have never had really good success with a mighty vac, maybe I am doing it wrong.

In the last 6 mos I purchased a couple of Mazda6's. One V6 and one I4. Whenever I buy a used car, brakes are the first thing I work over. The I4 needed a complete brake replacement, pads, rotors, caliper pins and boots. Used the partner method to flush and do fluid replacement. Everything went nicely. Brakes are perfect, pedal is firm just as expected.

Then came the V6. It needed pads, boots and fluid. I did it on a day with no helper available. I tried my mighty vac to no success, so I tried just opening the bleed valve, attaching a bleed hose, topping the MC and pumping the pedal. I was quite shocked to find that everything bled just fine with no air sucked back into the lines or cylinders. The pedal is firm. I never would have expected this.

I may try this on my 7 this weekend

 

I've bought the puny little brake bleeder kit from autozone for $5
The bottle is tiny, thus you have to empty it A LOT but for $5 I've already done 2 cars, by myself, and no issues.

 

I'm having weird issue w/my brakes, fluid level is perfect-no leaks...but if I pump/pulse the brakes somewhat quickly when braking (3+ pumps) the pedal gets very stiff and braking is reduced to almost ZERO!! Scary stuff when u gotta stop NOW!

Ideas? With the few I've talked with they seem to think its a vacuum issue...

 

It kinda does seem like a vacuum issue.
Is there free play in pedal?

 

Not anymore than normal...its weird, only seems to happen if I pump the brakes fairly quickly, if I mash 'em-no problem..

 

Kind of like when you shut the car off and pump the brakes; It gets super stiff? Probably the check valve.

 

Have you check the vacuum hoses that go to the brake booster?

The one next to the ACV likes to rot out.

 

^^I'll check that...