ams1

Hey all,

I have a '96 Accord, EX coupe with a 2.2 for starters. It has ABS.

This summer I have been trying to figure this problem out, but I thought I had it solved...I guess not.

A few months ago, my brake pedal randomly started to develop a fading pedal...when I push on the pedal, it slowly looses pressure and sinks to the floor, but as soon as I release, then reapply pressure, it had pressure for a few seconds then fades again.

After checking, I didn't have any visible leaks or fluid loss, so I automatically assumed it was the master cylinder going bad (clearly the original one). So I went to the local auto parts store and picked up a NEW one. While replacing this, one of the line bolts going into the master cylinder rounded off. Yes, I used a line wrench.... Then I used the bleeder kit, pumping the master cylinder a good 100 times. Then I bled the whole system (Furthest wheel to closest). The two front bleeder valves were not breaking loose, so it was bled from the lines. It was good for two days...


So, with these problems...it started to get worse...so It went to the dealer. Apparently, three of the four wheels had seized pads and I needed new rotors and pads in the front. He fixed the "seized pads" and took it for a test drive and said I was good...but guess what, got in the car...same problem. I fixed the pads and rotors (I know, such a b****). Good for a couple hours...then it started again.

I didn't drive the car for a few days afterwards. I got in and the brakes were normal. So I ignored it, okay it fixed itself, whatever. That was a little over a month ago. I drove took it on a 5 hour trip, got back no problem. Drove it yesterday around town...guess what, the fade was back...

Can anyone give me some insight? Thanks in advance

slowcivic2k

You have too many issues and you jump from one area to the next. The brakes should always be inspected from the wheel end forward. If you have dysfunctional pads or calipers, these must be corrected first. You cannot reliably bleed any wheel from a brake line, it must be done from the bleed screw, replace the caliper or wheel cylinder if it does not open, along with all other lines that break on the way.

If after all of this you still have a soft pedal, even with a new master cylinder AND it was bled properly, replace the ABS unit, as one of the accumulator seals has allowed fluid to leak to its return circuit.

ams1

I know I was all over the place, I just tried to explain everything in the order of events. This is just frustrating.

a. Any tips for breaking these bleeder valves loose?

b. if it were the ABS module, wouldn't there be an ABS light?

c. Is there a way I can test the ABS module before I get one.

MAD_MIKE

Incorrect bleeding procedure.
The system is diagonally split.
Driver rear to passenger front.
Passenger rear to driver front.
Using a very long tube, open the ABS bleed valve, it will purge. Close valve Refill ABS reservoir.
Start engine, allow ABS to purge. Turn off engine. Open ABS bleeder valve. Close valve Refill ABS reservoir. X3 to fully bleed ABS.

If you cannot open the bleeder valves you will not be able to properly bleed the calipers. If the nipples are seized drill them out and replace with new bleeder valves, or replace calipers. You cannot properly bleed through the brake line connection.

slowcivic2k

A: Use heat to loosen the bleed port. Heat the area AROUND the bleed screw and not the screw itself. If you do manage to remove it run a drill bit down the center of the bleeder to clear it of debris, and get a new dust cap.

B: No. When the ABS system is not engaged, there are no pressure sensors to determine leakage. The only thing the computer may possibly see is less wheel slippage during ABS braking. This can manifest itself in many ways, but will not leave a DTC in most cases.

C: You can test the solenoids and the motor itself, but these are all items the brake control hardware will test regularly. Since there are no pressure switches/sensors on the ABS housing, you will never obtain a DTC for an internal or external fluid leak.

ams1

Hey guys,

Thanks for the help. Sorry for reviving an older thread, but over the weekend I got the chance to really get into this.

I checked the back wheels first. I took the calipers off, checked pads, regressed everything, and made sure nothing seemed out of the ordinary. Nothing did.

I then checked all the lines, I couldn't see any evidence of even a remote brake leak anywhere. I couldn't get the bolts off for the channel between the front and back, but it was slotted we'll enough I could get a good look at the lines, the seemed like they may have to be replaced in a few years, but nothing that I believe would be causing a problem.

Then I went to try to wrestle with the bleeder valves. After a torch, lots of PB blaster (not at the same time ) and several tools that claim to get stripped screws out..one of the bleeder valves broke. After many curse words, I decided to go buy a couple new calipers for the front.

All I can say now is after installing them, and bleeding the whole system we'll...I am still having issues, but it is less apparent..but it's still there and annoying.

On my last trip to Oreillys for brake fluid, one of the people I usually talked to about Honda issues had arrived. He was talking to his friend and I explained to them what was going on. The employees friend said he has been chasing the same problem, and when it gets hot out, the pedal sinks, in the winter it doesn't.


That got me thinking...it doesn't sink as fast when it is cold out. And I believe I started to have this issue in the spring..not sure if that gives any insight on potential problems, but this is driving me crazy.

Long story short:

I replaced the front calipers.
Bled the whole system
Checked back disk brakes - looked good
Check lines, nothing looked bad
The problem may be somewhat temperature related

Thanks guys

slowcivic2k

The temperature change leads me to the master cylinder, as I have replaced many of these for the exact same problem. The Anti-Lock controller could also have a temperature sensitive internal leak, but I haven't seen this yet on a Honda, mostly Ford trucks.

If you are certain you are fully bled and have no leaks, replace the master cylinder.