fordmike1980

New member here, picked up a 96 civic coupe 2dr, with abs on the weekend. brakes felt spongy when i picked up the car. Car didnt have much history, so on my lunch break at work today, i replaced the master cylinder, both front calipers, pads, rotors, wheel cylinders etc.
I have been a technician for 7 years at a local ford dealer, and have never run into this issue.
Brakes are still spongy as hell. i bench bled the master , bled the brakes rr, lf, lr, rf as per all data. rear brakes are adjusted properly, no leaks.
Pressure bled the system about 2L of brake fluid following that pattern, still no change.
Pedal feels very firm with the car off, but running, she goes right to the floor.
Removed master and measured brake pushrod clearance with a micrometer, and depth of master - good.
So my question is this .., this car has abs. is there a chance the abs unit is bad, bypassing? or could i have a bad proportioning valve? both are fairly expensive parts in my neck of the woods, and just wanted to see if anyone else has had same sort of problems with the spongy / no brake and a faulty proportioning valve or bad abs unit?
Note: also tried capping off both lines off master and pressing brake pedal, and its firm, so i dont believe the new master is bad. i have good fluid flow out all bleeders. have tried pressure bleeding it, reverse bleeding it, and the usual 2 man bleed. ..
I also used the search function on this forum, and read an ton of threads, but most dont have a conclusion, or exhibit the same symptoms i am having.

Would appreciate any input.
Thanks

GIZZ - EXV

GiantDad

Are the hardlines corroded? That's a possibility, sometimes they rot threw and develop a small leak.

mk378

+1 on lousy chain store master cylinders.

Did you test drive yet? It may work better after the pads and shoes have been seated and the rear drums have adjusted themselves.

tony_2018

bench bleed mc?
bleed abs?
what order did you bleed?
how are your brake lines.

S2k@9K

iTrader: (3)

fordmike1980

I bled rr, lf, lr, rf . I bench bled the master, also bled the master on the car. My autel scan tool does not have abs bleed function on it, otherwise I would have tried it. The master I used was a Beck arnley master. When I can the ports on the master the pedal is rock hard so I do not think it's a bum master cylinder. I rebled the brakes again today and made sure rear brakes were properly adjusted. Still the same result. I managed to find a abs modulator and proportioning valve for 300 from a local auto wrecker. Going to install tommorow and re bleed. Is there away to bleed the abs unit by jumpering the pump on?

GIZZ - EXV

Bleeding Honda ABS isnt like bleeding Chevy ABS, there is nothing to it.

All the flex hoses are good? nobody pinched, nothing bulging?

fordmike1980

I watched all the brake hose's today while the lube tech pumped the brakes while bleeding today. no buldges in the lines, it looks like the previous owner has replaced the 2 front lines just recently as the plating on ends of the hoses look brand new.

I have been trying to find out how these honda proportioning valves work, i cant find any good info on mitchell, or all data, nor any luck on the google lol. it doesnt look too complicated as you can kind of see how it works looking at the casting of it.
I have run into problems with 97-08 f150's that exhibit a bad master cylinder symptoms, however after capping the ports on the master, it eliminates it, and it usually turns out to be a bad abs module with valve bypassing internally .
I am 600$ deep into this brake problem. i am not one to throw parts at things, but the only 2 things left is the abs module, and the proportioning valve. i will replace the proportioning valve first , and bleed and re-test. if still no go, i will replace the abs module next and retest. if that is the fix, i will definitley post up the answer. i have noticed a ton of threads on a spongy break pedal when engine running however, i am guessing once they find out the answer, they don't bother to post the results.

Anyone actually have had a bad prop valve before ? i have heard they rarely go bad

GiantDad

Go the the junkyard and ****** one.

fordmike1980

Ya I got both coming from a junkyard a few hours away. Wish there was a pick n pull closer to where I'm at

mk378

Again I ask have you driven the car yet with the new parts, or are you basing all this on what the pedal feels like when sitting still? Because you may find that the car stops effectively like it is.

fordmike1980

yes, the car has been driven to and from work the last few days with the new parts on it, same story, pedal sinks to the floor. and the car does not stop effectively at all. .

fordmike1980

Installed a used HCU (abs modulator assembly) bled the brakes, and pedal is perfect now..

farshadm

Hi

I am having the same issue with 2004 Honda Accord. Did you change the Abs Modulator?
What is the order of the bleeding that you did?

I got used abs modulator one from ebay and put it on but only bled the front wheels and not rear and still having spongy pedal going right to the floor

Thanks,
Farshad