Strange sounds coming from abs system (1 Viewer)

[alexszp]

Hey guys this has happened a couple times on my 2000 lc, now and finally managed to catch it on video. But I guess you can’t attach videos here ...

Strange squeezing sound from the abs system and sometimes (not always) the dash lights come on with a consistent beep. All of this goes away after I press the brake and all sounds completely stop. Drives fine and no signs of brakes malfunctioning while driving. Is this a sign that the system is going out, or something else?

 

[AlpineAccess]

Squeezing or squeeling?

 

[alexszp]

Squeezing or squeeling?

Yeah Squealing** sorry

 

[AlpineAccess]

It is typically a sign of the accumulator motor going out. When it's making the squeeling noise, use a mechanic's stethoscope or a piece of metal rod with your hand cupped over the end. Touch it to the accumulator on the brake master and listen, you'll know if its the culprit.

 

[JunkCrzr89]

How’s the fluid level?

 

[alexszp]

It is typically a sign of the accumulator motor going out. When it's making the squeeling noise, use a mechanic's stethoscope or a piece of metal rod with your hand cupped over the end. Touch it to the accumulator on the brake master and listen, you'll know if its the culprit.

Would this mean the whole assembly needs to be replaced?

 

[alexszp]

How’s the fluid level?

Fluid level is good.

 

[JunkCrzr89]

Fluid level is good.

You checked it properly (ie, Key OFF, pump pedal ~40 times or until it drops out)?

 

[alexszp]

You checked it properly (ie, Key OFF, pump pedal ~40 times or until it drops out)?

So I did this. Fluid level was up by the max line after pumping the pedal. After I turned the power on and the pump ran - and the fluid went down to a bit above the minimum line. As soon as the fluid got to that point is when the squealing started again.

 

[flintknapper]

Fluid old and dirty?

Sounds like a failing booster motor and/or accumulator but we are trying to eliminate some other possibilities for you.

How many miles on your Cruiser? What year model and do you believe the ABS unit to be the original?

Please put the year model of your rig in your signature line, so we will always know right away what we are dealing with.

 

[alexszp]

Thanks for the insight. It’s a 2000 landcruiser with 198k.

fluid does appear to be a bit old / dirty.

ABS unit appears to be original but I’ll attach an image as well.

 

[flintknapper]

Fluid doesn't look too bad.

Do the pump down test.

With key off, engine off, pump brake pedal 40 times or until the pedal feels soft goes towards the floor.

Then turn key on (but dont start engine) and listen to see that booster pump runs for less 45 seconds before it builds pressure and shuts off.

Let us know what you find. Also, peel back the two rubber covers on the wiring harness on the pump motor and inspect. I expect you'll find some corrosion there.

 

[alexszp]

Fluid doesn't look too bad.

Do the pump down test.

With key off, engine off, pump brake pedal 40 times or until the pedal feels soft goes towards the floor.

Then turn key on (but dont start engine) and listen to see that booster pump runs for less 45 seconds before it builds pressure and shuts off.

Let us know what you find. Also, peel back the two rubber covers on the wiring harness on the pump motor and inspect. I expect you'll find some corrosion there.

View attachment 2542032

I did the pump test see below

Fluid level was up by the max line after pumping the pedal. After I turned the power on and the pump ran - and the fluid went down to a bit above the minimum line. As soon as the fluid got to that point is when the squealing started again.

might be a dumb question but where does the wiring harness connect to the assembly?

 

[flintknapper]

I did the pump test see below

Fluid level was up by the max line after pumping the pedal. After I turned the power on and the pump ran - and the fluid went down to a bit above the minimum line. As soon as the fluid got to that point is when the squealing started again.

might be a dumb question but where does the wiring harness connect to the assembly?

View attachment 2542042

Not concerned with the fluid 'level' but the TIME it took for the pump to shut off.

There is a wiring harness/lead that goes from the ABS body to the pump motor. It is hard to see since it's at the bottom of the unit, but you can (just barely) reach them and peel them back exposing the screws and connection there. IF they are corroded there is a chance that the resistance is so great that the motor is not running properly. You want to eliminate that possibility.

 

[alexszp]

Not concerned with the fluid 'level' but the TIME it took for the pump to shut off.

There is a wiring harness/lead that goes from the ABS body to the pump motor. It is hard to see since it's at the bottom of the unit, but you can (just barely) reach them and peel them back exposing the screws and connection there. IF they are corroded there is a chance that the resistance is so great that the motor is not running properly. You want to eliminate that possibility.

View attachment 2542051View attachment 2542052

Leads in good shape (photo attached)

after pumping the brake the motor runs for about 40 second before stopping. This time it didn’t start to make any noise after running.

 

[alexszp]

Leads in good shape (photo attached)

after pumping the brake the motor runs for about 40 second before stopping. This time it didn’t start to make any noise after running.

 

[flintknapper]

All of that is excellent news.

A brake fluid 'flush' (ABS activated) might be appropriate, then just monitor it.

 

[alexszp]

All of that is excellent news.

A brake fluid 'flush' (ABS activated) might be appropriate, then just monitor it.

That’s good to hear. How exactly will a flush fix this from happening again?

should I be worried at all about the system failing on me?

 

[flintknapper]

That’s good to hear. How exactly will a flush fix this from happening again?

should I be worried at all about the system failing on me?

Removes any air/moisture that might be trapped in the ABS unit, Accumulator or lines AND is preventative maintenance that is supposed be performed at certain intervals anyway.

 

[alexszp]

Removes any air/moisture that might be trapped in the ABS unit, Accumulator or lines AND is preventative maintenance that is supposed be performed at certain intervals anyway.

Understood. No concern of failing system?