Brake pedal goes to floor and car coasts to a stop
 

Hey there, so I have a 2002 Civic LX and have been on an odyssey to figure out WTH is wrong with the brakes. A lot of times the pedal feels just fine. Then sometimes, for no rhyme or reason I can so far discern, it goes soft. It seems to happen particularly at low speeds, and particularly when I step on the brake a little bit, then push down on it much harder. It often (but not always) goes to the floor while the car glides to a stop.

I replaced the master cylinder with one from a junkyard a couple years ago (it used to be my wife's car); she says she doesn't remember whether it helped. I took it to a mechanic and he replaced the rear cylinders which were leaking, but that didn't solve the problem. Took it back to him, he bled the brakes again to get air out, and still the problem persists. My ABS light wasn't on, and upon suspecting it was burned out I took it to another mechanic who couldn't get his computer to communicate with the ABS via the OBD2 port. I removed the ABS pump and ABS F/S fuses thinking it was early ABS activation, and that didn't change much (the ABS light still didn't come on, so I believe it is in fact burned out).

I was just trying the thing where you push the pedal with the engine off, and it did NOT go to the floor. But then I drove it around the block and the brakes were fine at that particular time. I've been keeping an eye on the brake fluid level since getting it back from the mechanic and it hasn't gone down any perceptible amount.

Any ideas? This is driving me insane! Any chance the original master cylinder and the junkyard one had the same exact problem? Maybe I should try installing a brand new one?

Re: Brake pedal intermittently and unpredictably soft/spongy
 

Try running reverse some 30 ft then hard break; do It 3 times: this may help (no need for Mechanic or Money)

Adjust Rear Brakes by moving adjusting Cylinder on both sides till wheels spin just one complete spìn Do not touch brake handle between Seats; not necessary

Bleeding crossed ? FR then RL then FL then RR

Please, let me know results

Best Regards from Mexico City

Re: Brake pedal intermittently and unpredictably soft/spongy
 

PLEASE HELP!! My brakes are still in terrible shape and I'm at my wit's end.

I put a brand new master cylinder in. ABS is disabled. Booster is fine. This f'er has been bled more times than I can count, by mechanics and by me according to the procedure in the Haynes manual.

In a nutshell: panic braking works okay. But the kind of braking you do at stop signs/lights, the pedal goes clear to the floor and the car coasts to a stop. Tried Pepe_Oros' suggestion which didn't help.

Could it be too much free play? Do the rear brakes need adjusting? PLEASE help me out because I'm way too short on cash to take this thing to every mechanic in the world, or scrap it and buy a new car. Thanks.

Re: Brake pedal intermittently and unpredictably soft/spongy
 

The new master was bled ? (just making sure ) the ABS system being disabled could be a problem , it's usually best to run things as they were designed . If you bought a bargain master that could be the problem . My test for a bad master is to apply very light pressure on the brake paddle and if it makes it to the floor it's should be replaced . Brakes are no joke so don't drive it till it's fixed , if you've ever had brakes go out on you you'd know .

Re: Brake pedal intermittently and unpredictably soft/spongy
 

I see You did not bleed REARS ! So how do You expect to brake ?
Remember brakes work crossed. I read my post and seems to state NOT necessary; I was talking about brake handle as It is mechanic NOT HIDRAULIC

BLEED ALL FOUR WHEELS

Best Regards and tyre screeching

Re: Brake pedal intermittently and unpredictably soft/spongy
 

I've had a similar issue with my '01 Civic LX. The pedal never drops to the floor, but it tends to crawl around a bit under my foot, sometimes it sinks a bit, sometimes it actually pushes back against my foot a bit. It has done this since I first picked it up and I don't know what causes it, but I figure it's vacuum and/or brake booster related.