The ABS has been acting up for the past year on our 96 Accord.

Usually the pump would cycle after starting the car cold, would run for a few seconds and then turn off ... okay. But after making a short stop and restarting the engine after only a few minutes, the ABS light would come on.

Most recently the ABS pump started cycling repeatedly when starting the car, cycling about 19 times and then shutting off and lighting the ABS light.

Yesterday
-----------
Thinking that the accumulator O-ring was leaking, yesterday I pulled up the ABS modulator (did not disconnect the fluid lines) and replaced the accumulator O-ring. I also checked the underside of the accumulator and could see no evidence of fluid leakage. I did not replace the pump O-Ring at this time.

After an initial ABS bleeding attempt it seems as though I did not solve the problem. Pump still cycling 19 times before turning on the ABS light.

I then checked the ABS code ... 1-3, high pressure leak. I ran out of time so quit for the day.

Today
------

Bled the system a second time as best I could, and this time I got a few air bubbles out of the bleed, and the pump now appears to have stopped it's repeated cycling. The ABS light was on when I last parked the car, and haven't used it for the rest of the day, so I will find out tomorrow if the repeated cycling has stopped for good.

This morning I also tried the shortcut to cycle the pump, by tapping into the yellow/red wire in the ABS fuse box and grounding it using a voltage testing probe. I thought the wire was supposed to have no voltage on it and I would simply be grounding it to start the pump ... however the wire did have 12v on it, and when I touched it with my grounded probe it did not turn on the pump motor.

Did I do the jumpering correctly?

Thanks. John

 

The yel/red wire will have 12V if the relay is plugged in, because it is essentially connected to the yel/blk wire. The pump should have turned on from grounding that yel/red wire. If your tester has a high resistance, then that wouldn't work. You need a direct path to ground.

If you want to see if the pump motor runs, temporarily jump the power side of the relay. You could also supply power to the wht/blu wire at the ABS unit.

 

Thanks. The pump motor runs fine -- my concern was the manual activation method. But your explanation clears it up ... my probe has a very thin ground wire on it so must be high resistance ... I will try directly grounding the pin instead.

Fyi the pump cycling came back again. That could mean a pressure leak or a bad high pressure switch ... but I also want to make sure I have the last of the air bubbles out of the system. Knowing how to manually start the pump motor will help me to do this.

Thanks. John

 

The shop manual procedure says to manually open the bleeder, drain fluid, top of reservoir, then start the engine, repeat. The ABS should turn on for a few seconds when you first start the engine.

 

I did that.

However when I let all of the pressure out of the bleed valve, it drains more fluid than the reservoir holds ... so if I restart the engine and the pump ran for several seconds to fully pressurize, which drained the reservoir and let air into the system.

The first time I did this I ended up with foamy brake fluid. After sitting overnight the foam coalesced into bubbles I think, and this time I started the engine and ran the pump for only a couple of seconds, and then refilled the reservoir, and then restarted the engine to pressurize all the way. By filing the reservoir midway I avoided draining the reservoir

All in all that seemed a bit kluge way of doing it. A youtube video shows the method of jumpering the pump motor and bleeding for two seconds as the pump is running ... seems like an approach more consistent with how to manually bleed the regular brake system.