ABS Pump will not come on - real time help greatly appreciated

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Eliot

Eliot

10 Year
Joined
May 4, 2015
Threads
34
Messages
239
Location
Charleston, SC
Hey guys,

Dealing with an ABS pump issues on my '99 LX470 with 253k on the odometer. I'm experiencing all the issues people have posted about an ABS pump failure. (red) Brake light and ABS light came on with a buzzer. Pulled into the grocery store parking lot and as soon as I pulled into a parking spot the pedal just about went to the floor. I still have minimal braking at the bottom of the pedal travel.

I popped the hood and applied pressure to the brake pedal with my left hand on the abs motor, and it would not come on. I can hear the "ABS MTR1" relay clicking on and off, but the pump does not come on. My buddy with an LX470 came to give me a hand and we swapped the relay to test it. Works fine in his truck and his relay does not work in mine.

I did the master cylinder rebuild about 2 weeks ago. Opened the bleeder screw about 4 times on each caliber to bleed the brakes. Have had awesome brakes ever since the rebuild.

I've concluded the ABS pump will not come on for these possible reasons:
1. ABS pump is fried
2. There is air in the system and the pump will not come on (I've read this before on this forum where mud members have asked if there is a sensor that keeps the abs pump from coming on when there's air in there. The reason this makes sense is because when i first bled the brakes and clearly had air in the system, i got the same lights and buzzer on the dash)
3. Electrical connections to the ABS pump are corroded


A couple questions for anyone that has the time:
1. Does anyone have some insight they can share before I jump on a $2000 ABS pump replacement?

2. Can anyone confirm that if there's air in the system, the ABS pump will not turn on? I really think this could be it. The pump never screeched at me or made any noise. It was working great after i replace the master cylinder.

3. this kind of goes along with #2, but why would the abs light, (red) brake light and buzzer/alarm come on when i went to bleed the brakes (after reinstalling the master cylinder assembly)? Is there a sensor that recognizes there's air in the system?
 
When you replaced the MC, did you use the brake bleeding procedure written up in the forum FAQs?

Brake system flush

If so, and your brakes have been working well for 2 weeks, I'm going to guess its the infamous ABS accumulator pump motor failure. The year and miles on your cruiser fit the pattern for potential failures. If the motor won't run, I don't see how you can try bleeding the brakes again. There are write-ups on MUD about rebuilds for the pump failures, so you may be able to get away with a less than $2000 brake repair.
 
glad you didn't experience brake failure at high speed. No expert on this but I doubt the alarm would be triggered by air in the system. I imagine it's fluid level, pressure and the like. Yes, check the many threads about the issue and cheaper repair. (And vote in the survey!)

I would be very leery of driving it on a public road at any more than creeping speed, if that.
 
Sandroad said:
When you replaced the MC, did you use the brake bleeding procedure written up in the forum FAQs?

Brake system flush

If so, and your brakes have been working well for 2 weeks, I'm going to guess its the infamous ABS accumulator pump motor failure. The year and miles on your cruiser fit the pattern for potential failures. If the motor won't run, I don't see how you can try bleeding the brakes again. There are write-ups on MUD about rebuilds for the pump failures, so you may be able to get away with a less than $2000 brake repair.
Click to expand...

I followed every part, except for activating the ABS and then re-bleeding. I guess my error could be here?

e9999 said:
glad you didn't experience brake failure at high speed. No expert on this but I doubt the alarm would be triggered by air in the system. I imagine it's fluid level, pressure and the like. Yes, check the many threads about the issue and cheaper repair. (And vote in the survey!)

I would be very leery of driving it on a public road at any more than creeping speed, if that.
Click to expand...

I'm very lucky this happened at low speeds and that I was the only one in the vehicle. I already voted on the survey! If it turns out the be the pump, i'll have to change my vote. That survey was actually the reason I was so aware of the situation when it happened. Very glad to have read through everyone's experience prior to it happening to me. Could have turned out a lot worse if I didn't pull over when I did.
 
Eliot said:
Hey guys,

Dealing with an ABS pump issues on my '99 LX470 with 253k on the odometer. I'm experiencing all the issues people have posted about an ABS pump failure. (red) Brake light and ABS light came on with a buzzer.

I've concluded the ABS pump will not come on for these possible reasons:
1. ABS pump is fried
2. There is air in the system and the pump will not come on (I've read this before on this forum where mud members have asked if there is a sensor that keeps the abs pump from coming on when there's air in there. The reason this makes sense is because when i first bled the brakes and clearly had air in the system, i got the same lights and buzzer on the dash)
3. Electrical connections to the ABS pump are corroded


A couple questions for anyone that has the time:
1. Does anyone have some insight they can share before I jump on a $2000 ABS pump replacement?

2. Can anyone confirm that if there's air in the system, the ABS pump will not turn on? I really think this could be it. The pump never screeched at me or made any noise. It was working great after i replace the master cylinder.

3. this kind of goes along with #2, but why would the abs light, (red) brake light and buzzer/alarm come on when i went to bleed the brakes (after reinstalling the master cylinder assembly)? Is there a sensor that recognizes there's air in the system?
Click to expand...

Fits the pattern of a failed ABS motor, but here's my 2 cents.
Air in the system won't inhibit the pump motor and stop it charging the accumulator. When low pressure is detected in the system the pump motor is suppose to kick in to boost pressure, so you could be looking at a failed pressure switch but its a distinct possibility your motor has failed with a worn out commutator/brushes shot. Another possibility is a bad connection between the motor controller and motor itself.
I'd induce the situation where your ABS pump motor is suppose to come on and see if you're getting battery voltage at the motors' terminals. Ignition off and pump the brake peddle 40 times - as per FSM - ignition back on and the pump is suppose to run for approx 30 to 40 seconds. Having already pulled down the rubber cable hood to expose the two terminals to the motor see if you're getting 12v +. Check the connections are tight and not loose or corroded. If there's voltage being applied to the motor but no action then give it a sharp whack, if the commutator and or brushes are worn out you might be able to jolt it back to starting. This isn't a fix by any means, just may give further evidence of a dying motor. There's not much room to get at the terminals but it's worth confirming, or otherwise, if you're getting power to the motor. You could also just disconnect the blue and red leads off the bottom of the controller and jump battery voltage to them and see if the motor turns. Red should be +, polarity shouldn't matter if you just touch power to the leads for a second to see (hear) if the motor turns.
 
PADDO said:
Fits the pattern of a failed ABS motor, but here's my 2 cents.
Air in the system won't inhibit the pump motor and stop it charging the accumulator. When low pressure is detected in the system the pump motor is suppose to kick in to boost pressure, so you could be looking at a failed pressure switch but its a distinct possibility your motor has failed with a worn out commutator/brushes shot. Another possibility is a bad connection between the motor controller and motor itself.
I'd induce the situation where your ABS pump motor is suppose to come on and see if you're getting battery voltage at the motors' terminals. Ignition off and pump the brake peddle 40 times - as per FSM - ignition back on and the pump is suppose to run for approx 30 to 40 seconds. Having already pulled down the rubber cable hood to expose the two terminals to the motor see if you're getting 12v +. Check the connections are tight and not loose or corroded. If there's voltage being applied to the motor but no action then give it a sharp whack, if the commutator and or brushes are worn out you might be able to jolt it back to starting. This isn't a fix by any means, just may give further evidence of a dying motor. There's not much room to get at the terminals but it's worth confirming, or otherwise, if you're getting power to the motor. You could also just disconnect the blue and red leads off the bottom of the controller and jump battery voltage to them and see if the motor turns. Red should be +, polarity shouldn't matter if you just touch power to the leads for a second to see (hear) if the motor turns.
Click to expand...

Appreciate the info. Definitely a good approach. I ended up just having it towed the shop last night. It's worth the money for me to just have them tell me what's wrong so i'm not trying to diagnose it with my multimeter.

I got just a few hours ago and was informed the motor is seized up and has failed. The circuit is complete and the motor is getting 12v, so the motor must be bad. $1611 for the part + labor. It hurts...kinda burns too. It'll give me piece of mind though, just to have a nice brand new OEM pump in there. That'll hopefully get me to the half million + miles i plan on running this truck.

Pretty coincidental that this happens 2 weeks after i did the master cylinder rebuild. Very positive i did a bang up job on the rebuild, but maybe botched the bleed process. Not convinced this caused my failure though. It seems like it was just pure coincidence.

Thanks all that responded, I really appreciate the feedback.
 
Eliot said:
Appreciate the info. Definitely a good approach. I ended up just having it towed the shop last night. It's worth the money for me to just have them tell me what's wrong so i'm not trying to diagnose it with my multimeter.

I got just a few hours ago and was informed the motor is seized up and has failed. The circuit is complete and the motor is getting 12v, so the motor must be bad. $1611 for the part + labor. It hurts...kinda burns too. It'll give me piece of mind though, just to have a nice brand new OEM pump in there. That'll hopefully get me to the half million + miles i plan on running this truck.

Pretty coincidental that this happens 2 weeks after i did the master cylinder rebuild. Very positive i did a bang up job on the rebuild, but maybe botched the bleed process. Not convinced this caused my failure though. It seems like it was just pure coincidence.

Thanks all that responded, I really appreciate the feedback.
Click to expand...


Piece of mind is priceless especially with this important component. If you can wait for a little longer, I can get you the booster pump with accumulator for a little less than $1k ;)

98-07 Genuine Toyota 100 series and LX470 Brake Booster with Accumulator
 
Eliot - what was the final resolution? Dealing with the same thing right now. Thanks.
 
okryan said:
Eliot - what was the final resolution? Dealing with the same thing right now. Thanks.
Click to expand...

It was an ABS pump failure. The pump had seized up. Applying 12v directly to the pump and got nothing. I ended up getting the shop to replace with a new unit. I have the old pump because I plan to diagnose the issue, just haven't had time recently.

I would check your relays and electrical connections, could get lucky there. Unfortunately it's most likely the pump. My LX is my daily so I had to get it fixed immediately ($2100). If you can afford to work on it for a week or two there's plenty of good vendors on here that could hook you up with a pump for around $1000 or so. Shouldn't be a very hard install and then bleeding the brakes is easy. Good luck
 
one of those things you want to fix and fix well!
 
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