Blown ABS? '94 Accord DX
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Joined: Jun 2002
Posts: 79
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From: SF Bay Area, CA
Blown ABS? '94 Accord DX
Ouch, *not* a good evening for driveway wrenching.
I was doing a brake fluid change on my father's BMW with the Mityvac. Said, "Hey, while I have all these tools out, I'll change the brake fluid in the ABS on the Integra and the Accord."
Both of those cars have had brakes bled as part of pad changes in the last year, but haven't had the fluid in the ABS changed for about three years. Definitely time.
Did the Integra first. Hooked up the Mityvac to the bleeder on the ABS, cracked the screw, let out 3 or 4 ml of yellowy old fluid, shut the screw, started the engine, let the ABS pump activate to pressurize, shut the engine down, added new fluid to the ABS reservoir to bring the level back to spec. Repeated that process a few times until the bled fluid flowed clear. No problems at all. Done it before on both these cars.
Then I did the same gig on the Accord, and all shiznit broke loose.
Here is what I think happened: I think I was distracted, and drained way too much fluid on one bleed cycle, and did not add enough matching fluid back into the ABS reservoir. When I hopped in and started the engine, I heard the buzz as the ABS pump started up. That's normal. But it usually runs for about five seconds. This time, it ran for about 25 seconds before I said, "Something is out of whack," and shut down.
The reservoir was totally empty when I looked. D'oh! The works had gone dry.
Filled the reservoir. Started up again. ABS light came on at the initial idiot-light-demo point of starting up, then went out. Whew, what a relief. Took a test drive around the block. ABS light came on while halfway home. Oh, eff me. Not a relief.
Back to driveway. Shut down. Restart. ABS light came on at first during the keyturn light-demo, then went out. OK, normal. Then the light came back on (with a click from behind the glove box) about 40 seconds after startup, and stayed on.
Still short on fluid? I looked. Plenty of it. Slightly overfilled.
Restarted and shut down a few more times. Realized that there was no familiar buzzing sound of the ABS pump coming on to pressurize the system.
There should be an ABS DTC code stored if there is warning light. I jumped the diagnostic connector. Code one: pump motor overrun. The same code was repeated three times.
Okay, so the ABS pump motor overran, past tense, why won't it run now? Plenty of fluid. Maybe the pump won't run if there's a code in the memory. I pulled the ground from the battery and waited 15 minutes.
On restart, the ABS light came on at first keyturn, went out after engine start, and then, click, came back on after 40 seconds, same as before. I fetched the DTC, which showed a single code one.
I've got a really bad feeling here that the reason the pump won't run is because the thing went overtemp or overcurrent and died.
I was doing a brake fluid change on my father's BMW with the Mityvac. Said, "Hey, while I have all these tools out, I'll change the brake fluid in the ABS on the Integra and the Accord."
Both of those cars have had brakes bled as part of pad changes in the last year, but haven't had the fluid in the ABS changed for about three years. Definitely time.
Did the Integra first. Hooked up the Mityvac to the bleeder on the ABS, cracked the screw, let out 3 or 4 ml of yellowy old fluid, shut the screw, started the engine, let the ABS pump activate to pressurize, shut the engine down, added new fluid to the ABS reservoir to bring the level back to spec. Repeated that process a few times until the bled fluid flowed clear. No problems at all. Done it before on both these cars.
Then I did the same gig on the Accord, and all shiznit broke loose.
Here is what I think happened: I think I was distracted, and drained way too much fluid on one bleed cycle, and did not add enough matching fluid back into the ABS reservoir. When I hopped in and started the engine, I heard the buzz as the ABS pump started up. That's normal. But it usually runs for about five seconds. This time, it ran for about 25 seconds before I said, "Something is out of whack," and shut down.
The reservoir was totally empty when I looked. D'oh! The works had gone dry.
Filled the reservoir. Started up again. ABS light came on at the initial idiot-light-demo point of starting up, then went out. Whew, what a relief. Took a test drive around the block. ABS light came on while halfway home. Oh, eff me. Not a relief.
Back to driveway. Shut down. Restart. ABS light came on at first during the keyturn light-demo, then went out. OK, normal. Then the light came back on (with a click from behind the glove box) about 40 seconds after startup, and stayed on.
Still short on fluid? I looked. Plenty of it. Slightly overfilled.
Restarted and shut down a few more times. Realized that there was no familiar buzzing sound of the ABS pump coming on to pressurize the system.
There should be an ABS DTC code stored if there is warning light. I jumped the diagnostic connector. Code one: pump motor overrun. The same code was repeated three times.
Okay, so the ABS pump motor overran, past tense, why won't it run now? Plenty of fluid. Maybe the pump won't run if there's a code in the memory. I pulled the ground from the battery and waited 15 minutes.
On restart, the ABS light came on at first keyturn, went out after engine start, and then, click, came back on after 40 seconds, same as before. I fetched the DTC, which showed a single code one.
I've got a really bad feeling here that the reason the pump won't run is because the thing went overtemp or overcurrent and died.
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Joined: Jan 2003
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Yeah, keep bleeding to work out the air. (Don't let the reservoir go empty...)
I've let the reservoir go empty the first time bleeding on my Integra. After getting the air out there were no problems.
Still, it's 11 years old. Look for dirty/corroded wiring harness connections at the ABS unit.
I've let the reservoir go empty the first time bleeding on my Integra. After getting the air out there were no problems.
Still, it's 11 years old. Look for dirty/corroded wiring harness connections at the ABS unit.
Thread Starter
Member
Joined: Jun 2002
Posts: 79
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From: SF Bay Area, CA
Okay, got it working again. Thanks, you two!
For anyone stuck in the same position in future:
Merely opening the bleeder screw on the ABS unit did not expel enough fluid/air to get the pump to run again. I had to pull about 60 kPa of vacuum with the Mityvac and open the screw pretty wide to get out a last few drops of fluid, plus who knows how much air.
At that point, when next I turned the car on, the pump was heard to run briefly, and the fluid level in the reservoir dropped about 1.5cm from the top. I refilled to MAX and sealed everything back up. Seems happy now.
For anyone stuck in the same position in future:
Merely opening the bleeder screw on the ABS unit did not expel enough fluid/air to get the pump to run again. I had to pull about 60 kPa of vacuum with the Mityvac and open the screw pretty wide to get out a last few drops of fluid, plus who knows how much air.
At that point, when next I turned the car on, the pump was heard to run briefly, and the fluid level in the reservoir dropped about 1.5cm from the top. I refilled to MAX and sealed everything back up. Seems happy now.