Wolf95

Hey guys, I searched but couldn't find a thread on what to do after replacing an ABS module. So here goes...

My MY00 AP1 has had a weird braking issue since I've owned it (bout a year and a half). 162k miles on the car. At about 5-7 mph when braking or rolling to a stop I will feel a clatter/grind in the brake pedal and recently I've heard a psssst coming from around the master/abs module area. Now this is NOT a warped rotor feeling.

What I've narrowed out so far... Replaced three... yep, THREE stuck calipers, cleaned all abs sensors, replaced all four lines with Stainless braided lines, bled and bled and bled, even engaged abs a few times to see if it would help/go away, and check for leaks everywhere. The car stops fine, no air in the lines and no hesitation from the pedal. Just has this annoying thing happen at the same speed just about every time. Even pulling into my driveway after I release the brake pedal and start coasting it'll do it until it hits 4 mph. NO CODES. I also pulled the ABS sensor fuse over winter and it never did it, of course abs never engaged either...

So I'm 98% sure this is an abs problem. Now I got a used (70k miles) ABS module from a friend after he deleted abs from his. I will probably end up installing it later today but before I start I have a couple questions..

1)Is there an ABS reset to configure the new module to the system?
2)is there a different bleed procedure besides consistant billman bleeding, a couple back road engagements, and rebleed?
3)If this doesn't fix it, is there another BCM that controls abs to look at?

Thanks for any advice. Next step will be a trip to the dealer...

MM3Kwolik

Have you bothered checking your Brake Master Cylinder or your Brake Booster? If the Booster is Perforated it may give you some inconsistent pedal feel. I'd check those before doing the work to replace the ABS modulator. As for replacing it, the only way to truly get all the air out is to use the Honda PGM tool, so I'd be hesitant to jump the gun on the module.

Wolf95

But braking IS consistent. I have not figured out how to narrow out those two except for replacement, which I know boosters aren't cheap...

MM3Kwolik

If you're hearing air around your master/module, you most likely have a hole in part of your booster OR there is a hole in the line going from the booster to the engine. Be very careful when replacing that line though. Don't think you can just go to the store and pick up a piece of universal hose and call it good. No dice. That line has a check valve in it that keeps the booster pressurized in the case of an engine failure, that way your brakes still work appropriately and you can still safely stop.

Wolf95

That is correct. I pulled the line off the booster and it released the residual vacuum, ensuring it is holding vacuum. Wouldn't pulling the abs fuse and it going away narrow out the possibility of a bad booster/BMC? Wouldn't it still do it with ABS disengaged? This is why I jumped to the assumption of the module being faulty. I was asking some other friends that graduated from our auto program and they both mentioned a halfway stuck dump valve in the module could be a possibility. It's been a while since I've taking a brakes class so I can't remember this exact ABS setup.

MM3Kwolik

I totally missed the point where you said pulling the ABS fuse made it go away. I'd say that's a pretty likely cause then.

Wolf95

Wolf95

Any tips on bleed procedure without the Honda scan tool?

MM3Kwolik

Bleed brakes as usual and go find a gravel road and do some semi-aggressive braking to try and get the air out of the pump. Every few runs, bleed the brakes again. Keep doing this until everything feels right.

Wolf95

Thanks. Haven't had a chance to have a day off to do this. Should be this week or next.