2000 LX470 - ABS motor constantly running, with pulsing brake fluid level (1 Viewer)

[rainmann97]

I had a 1st gen Sequoia for several years, and just traded for an LX470. I heard the ABS motor running and didn't realize what it was. I was driving and all the warning lights and the chime came on. I gently drove home trying to plug my ears.

I pumped the brakes 40 times. When I turn the key to run, and the pump runs constantly. After about 50 seconds there is a pulsation sound that begins, and I can visibly see the brake fluid level pulsing in the reservoir. Here is a link to a video I recorded showing the issue. The pulsing sound comes in about halfway through.

The pump running constantly makes me think the accumulator has failed, but I haven't been able to find any info online about the pulsing sound with that. Hoping for some help from folks here.

 

[leveeguy]

The brake fluid is low and that is not good if its been this way for a while. I'd add fluid to max line after pressing brake pedal 20 - 40 times and see if that helps correct this issue.

 

[rainmann97]

The brake fluid is low and that is not good if its been this way for a while. I'd add fluid to max line after pressing brake pedal 20 - 40 times and see if that helps correct this issue.

Well it was actually above the max line, so I removed some to get it down to the max line. Then in the process of pumping the brakes and letting the pump run it went to the min line.

 

[leveeguy]

Ok note that the brake fluid level should be set properly to max line AFTER pumping brake pedal 40 times with engine off as stated on reservoir cap. Pumping the pedal with vehicle OFF actually raises the fluid level in reservoir.
The area in pic I’ve circled looks like brake fluid is missing and this area should be full of fluid in the video. If that is correct may be indication of what the issue is.

 

[rainmann97]

Ok note that the brake fluid level should be set properly to max line AFTER pumping brake pedal 40 times with engine off as stated on reservoir cap. Pumping the pedal with vehicle OFF actually raises the fluid level in reservoir.
The area in pic I’ve circled looks like brake fluid is missing and this area should be full of fluid in the video. If that is correct may be indication of what the issue is. View attachment 3884195

During filming the video, the fluid is right at the level of the toyota/aisen label. Additionally, the fluid was literally to the top when I had previously pumped and then let the system prime (still with indefinite pump running). I actually thought the level being too high was the issue.

 

[2001LC]

Check entire system for leaks. (Master, hard line, flex lines (leaks or bubbles), calipers, bleeders).
You could then try, flushing and bleeding system "properly". This includes setting level properly in reservoir in the manor embossed on it.

Accumulator. Empties, as we pump pedal 40 times, IG key OFF. Then fills (pressurize) once IG key ON and booster motor runs pumping fluid into it. The fluid level in reservoir, changes by about half the distance between min. & max. lines. Much more, could mean a failed accumulator.

New master resevoir fluid drawdown, after booster motor/pump stops. 29 second at 12.7volt battery

Pulsing sound, is motor & pump run to long. Which FSM warns us, do not run more than 2 minutes when working on system. Also running pump dry, can damage pump. Since new to you, it's may be PO did run dry.

Brakes ...... Overdue write-up.

First and foremost: Brakes should only be worked by those, with high level of mechanical abilities and experienced with brake systems. With the age of all 100 series today, in our aging fleet. Any issue, with brake master assembly. IMHO, best and safest course of action. Have the whole brake...

forum.ih8mud.com

Overfilling will not hurt. It just when we do, fluid comes out cap and or resevoir grommets. It then gets on wires, and can cause damage to motor.

If no leaks or damaged lines, and proper flushing and bleeding done, with Toyota brake fluid. Doesn't correct!. You could try overfilling just enough to keep above low line. The more fluid the accumulator needs to charge, the less nitrogen charge behind the bladder.

Perhaps find a used accumulator around, that's not to old. For a test.

It could even be a bad pressure sensor. Or damaged wire (rodents)

But warning Dealerships just replace the whole master, for good reason. Once they know no leaks, proper fluid and no shorts in wiring.

 

[rainmann97]

Check entire system for leaks. (Master, hard line, flex lines (leaks or bubbles), calipers, bleeders).
You could then try, flushing and bleeding system "properly". This includes setting level properly in reservoir in the manor embossed on it.

View attachment 3884906

Accumulator. Empties, as we pump pedal 40 times, IG key OFF. Then fills (pressurize) once IG key ON and booster motor runs pumping fluid into it. The fluid level in reservoir, changes by about half the distance between min. & max. lines. Much more, could mean a failed accumulator.

New master resevoir fluid drawdown, after booster motor/pump stops. 29 second at 12.7volt battery
View attachment 3884936

Pulsing sound, is motor & pump run to long. Which FSM warns us, do not run more than 2 minutes when working on system. Also running pump dry, can damage pump. Since new to you, it's may be PO did run dry.

Brakes ...... Overdue write-up.

First and foremost: Brakes should only be worked by those, with high level of mechanical abilities and experienced with brake systems. With the age of all 100 series today, in our aging fleet. Any issue, with brake master assembly. IMHO, best and safest course of action. Have the whole brake...

forum.ih8mud.com

Overfilling will not hurt. It just when we do, fluid comes out cap and or resevoir grommets. It then gets on wires, and can cause damage to motor.

If no leaks or damaged lines, and proper flushing and bleeding done, with Toyota brake fluid. Doesn't correct!. You could try overfilling just enough to keep above low line. The more fluid the accumulator needs to charge, the less nitrogen charge behind the bladder.

Perhaps find a used accumulator around, that's not to old. For a test.

It could even be a bad pressure sensor. Or damaged wire (rodents)

But warning Dealerships just replace the whole master, for good reason. Once they know no leaks, proper fluid and shorts in wiring.

Yeah that is probably where I'll be at. I can't find contact info for Andy Lee, who everyone recommends for purchase of rebuilt units. Perhaps someone here can offer that info.

 

[2001LC]

I would never recommend a rebuilt master. Not until someone proves: They can replace seals in master, also clean/test screens, passages, valves and circuits with ABS unit.