Brake Booster Motor Failed? (1 Viewer)

[100d ua]

Hey all, wife called to let me know that the following lights appeared on the dash with a loud buzzing/ringing noise: ABS / VSC TRAC / VSC OFF / BRAKE

(AAA is on the way to pick-up the car)

The kind folks on the Land Cruiser Facebook page let me know it should definitely not be driven because its a brake failure warning and as I was on the phone with the wife she confirmed the brakes felt "awful". She was still at her work parking lot so she didn't make it out onto the main roads.

I need help understanding this after doing my own research so I can start the diagnosis ASAP.

1) Is this failure of the Brake Booster Motor or is the entire unit it's attached to? (which looks very $$$)

2) What are the diagnosis methods? Scan for codes?

3) How many ugga duggas (Banana difficulty) is this to DIY?

The car is a PNW car with no rust, not sure if that makes a difference or not.

Thanks all...




(what I mean by "entire unit" mentioned in line #1)

Brake Booster Motor:

"Entire Unit"

 

[FxFormat]

Look at the sticky thread above the forum, scan through that, seems like symptoms of a brake booster failure.

 

[udubfl]

Wishing you it’s only the booster because “Entire Unit” cost me over $3500 last year. That was OE parts and labor (replace, bleed, refill, etc.).

Our 2001 LC with 170k or so had the same lights and buzzer go off. Regular driving patterns and nothing out of ordinary to cause it to fail. I had my local Toy Indy pull the codes (instead of my simple blue tooth coder) and visual inspect the system and eventually went with entire unit route because time was the essence and my lack of confidence in messing with MC.

Good luck!

 

[100d ua]

Little update: I went to go check out the car and while inspecting under the hood I gave the round motor thing a light tap with my knuckles and fired the car back up.

The buzzing and lights were still on so for s***s and giggles I turned on the diff lock and while I was looking at something on my phone the buzzing and lights went away.

I drove the car around the parking lot and everything feels perfectly fine. However, now I can’t turn off the diff lock.

I found a guy that rebuilds the motor for $450 and seems like that’s solved about 90% of people’s issues.

Any ideas?

 

[hickuptruck]

This issue is all very documented and there's at least 30 pages of it in the forums. Yeah you might be able to get Away with a rebuild kit, maybe not. I did accumulator orings silencer tube, spring and booster motor and the warning lights persist.

Don't drive your LC until you fix your brakes

Get techstream, scan the codes, fix. youll need techstream anyways to bleed abs

 

[kruisinkid]

also this one active just yesterday

and for fun i just did a quick spreadsheet of all the parts one COULD replace a la carte vs buying the entire assembly (motor pump, accumulator, MC body assmbly) and it is wildly cheaper to buy the complete assembly.

for 99-02
entire assembly 2178.27$

 

[2001LC]

First, pull the codes and see what set off the "loud buzzing/ringing noise: ABS / VSC TRAC / VSC OFF / BRAKE "?
Note: Any parts store will pull codes for you.

Second, note the OAT (Outside air temperature) when incident accrued.?

Third, check brake fluid level, (hint: procedure is embossed on reservoir)?

Forth, test brake booster motor run time?

CDL switch not used often tend to stick. Keep working switch. Push it once hard and wait, then back up and pull forward. Repeat, repeat, repeat.

 

[100d ua]

UPDATE:

Car is home and I had a chance to minimally tinker with it. Everything is fine... NO ABS lights or buzzing/ringing noises, brake pedal feels fine. Here are some things I observed.

Last night when I went to go pick-up the wife, the brake fluid was above the MAX line. Today, and after the ringing and lights turned off, the brake fluid is noticeably below the MAX line.
(I took pictures of the reservoir before and after the warning/lights)

Now here's the problem. I CANNOT get the VSC OFF and CENTER DIFF LOCK light to turn OFF. I have tried reversing tightly, coasting in neutral backwards and forwards, I have tried it in Park and Neutral. I have used the diff lock many time and NEVER had an issue with it. The only two things I can think of are that when they sent the first tow truck they lifted the back wheels up with the intention of putting the forward wheels over dollies since it was not a flat bed. I told them NO, I want a flatbed. I don't think that would do anything though, would it? Raising both rear wheels up into the air?

Secondly, it's been cold lately... about as cold as it really gets in Oregon... 30-40 degrees lately.

Is it possible I blew the fuse for the VSC or something?

 

[Infinity00]

I don’t think you should drive it even though everything seems fine. Have you looked thru the posts on the poll for brake failures? Your symptoms follow others and the brakes can completely fail after what you have described including the part about it feeling fine after the Christmas lights come on. Keep talking to 2001LC, and I’ll post the link to the poll if you haven’t seen it.

Poll on total brake failure in 100 series

There is some discussion going on of total and sudden braking failure in 100 series models, with reports of no -or essentially no- braking left at all a very short time (of the order of seconds/minutes) after dashboard warnings. That is scary stuff. It is, however, also difficult to find out...

forum.ih8mud.com

what year is your vehicle?

 

[100d ua]

I don’t think you should drive it even though everything seems fine. Have you looked thru the posts on the poll for brake failures? Your symptoms follow others and the brakes can completely fail after what you have described including the part about it feeling fine after the Christmas lights come on. Keep talking to 2001LC, and I’ll post the link to the poll if you haven’t seen it.

Poll on total brake failure in 100 series

There is some discussion going on of total and sudden braking failure in 100 series models, with reports of no -or essentially no- braking left at all a very short time (of the order of seconds/minutes) after dashboard warnings. That is scary stuff. It is, however, also difficult to find out...

forum.ih8mud.com

what year is your vehicle?

Definitely not driving it around. I only drove it up and down the street in front of my house to try and get the center diff to unlock. No success and it will remain in the garage until the motor is replaced.

 

[2001LC]

I see so often the reservoir overfilled.

 

[uHu]

I thought the japanese was a bit hard to read...

 

[2001LC]

Nice lighting.

 

[2001LC]

Once topping procedure done. Put IG key in and turn to on (don't start) with hood open and stopwatch ready. Time how long booster motor runs from start to finish (be precise). Spec is 30 to 40 seconds. Repeat topping procedure and time at least three times in a row. Also count how many pumps of brake pedal it takes until stroke become long (pedal drops out). Do this on very cold morning before using brakes or starting. Also repeat after active use. Keep a log of all date you collect, including OAT (outside air temp).

If at any time motor fails to start after the evacuation of accumulator (topping procedure). It is likely you motor is failing. Often I see the commutator of motor with dead spots. Motor brushes will land on a dead spot and motor will not turn on. I find a direct correlation to the brake control wire having corrosion in these cases. If for any reason the motor runs to long to often, they wear out early. In those the brush and commutator is worn out.

Pull you codes even if no check engine lite or ABS light. Then clear codes and see what returns.

__________ Also_______________
When very cold OAT, seal shrink. This combine with age and we get a pressure drop from brake pressure bleed off (Leaks & weeps). This can set off alarms and make brake pedal spongy. Then after use or warming of OAT, all is well again. Caliper piston seals as well as those of master, is now in question. System not flushed regularly count on needed new pistons in calipers.

Best way to avoid a lot of this, is proper flushing and often, with proper topping its entire life. Checking pedal stroke & runs times periodically can yield clues and head-off issues.

 

[MissouriLC]

Once topping procedure done. Put IG key in and turn to on (don't start) with hood open and stopwatch ready. Time how long booster motor runs from start to finish (be precise). Spec is 30 to 40 seconds. Repeat topping procedure and time at least three times in a row. Also count how many pumps of brake pedal it takes until stroke become long (pedal drops out). Do this on very cold morning before using brakes or starting. Also repeat after active use. Keep a log of all date you collect, including OAT (outside air temp).

If at any time motor fails to start after the evacuation of accumulator (topping procedure). It is likely you motor is failing. Often I see the commutator of motor with dead spots. Motor brushes will land on a dead spot and motor will not turn on. I find a direct correlation to the brake control wire having corrosion in these cases. If for any reason the motor runs to long to often, they wear out early. In those the brush and commutator is worn out.

Pull you codes even if no check engine lite or ABS light. Then clear codes and see what returns.

__________ Also_______________
When very cold OAT, seal shrink. This combine with age and we get a pressure drop from brake pressure bleed off (Leaks & weeps). This can set off alarms and make brake pedal spongy. Then after use or warming of OAT, all is well again. Caliper piston seals as well as those of master, is now in question. System not flushed regularly count on needed new pistons in calipers.

Best way to avoid a lot of this, is proper flushing and often, with proper topping its entire life. Checking pedal stroke & runs times periodically can yield clues and head-off issues.

Dealt with this issue myself back in October...

“Total” brake failure yesterday... accumulator pump motor CONFIRMED

Most likely, you have the same issue I had; part of the pump motor commutator is worn through. This means that the pump will run sometimes, but if it stops on one of the dead spots, it won’t start again on its own.

Mine was failing intermittently for almost a year before it failed for good.

Job was complicated, but not hard. I would say servicing wheel bearings or replacing an alternator is objectively harder. It is time consuming though, so best if you can have the vehicle off the road for a few days to take your time.

I was able to fix mine over the course of a week for less than $400, as detailed in my thread.

Good luck!

 

[100d ua]

I noticed this morning the brake fluid in the tank was above the MAX line and had a feeling the buzzing/lights would come back. I turned the key to the ACC position and watched the fluid drop a few MM before stopping above the MAX line and as I presumed, the lights and ringing noise came back.

I already have a refurbished motor on the way and plan on swapping it out sometime next week. I am still not understanding why my diff lock will not turn off and if it has anything to do with this or not.

 

[kruisinkid]

just for clarity, are you replacing just the separated motor or the "motor pump" with the pump head?
i thought on a cold truck, the brake fluid is always above max, and once the truck is turned on, the pump charges the accumulator and thus the brake fluid level goes down to about the max line (if the proper fill procedure is followed as stated on reservoir)?
you are then getting lights and alarms because the pressure sensor is not seeing the accumulator pressure rise to the desired psi?
while the lights and alarms are happening in the driveway at startup, what if you pump the brakes 40 times, does the alarm and lights stop?
in a 'total brake failure" as some have experienced, has anyone pumped the brakes about 20 times in between moments of soiling your underwear as your hurdle down the road with no brakes? isnt that the old trick to build pressure in the system?

again, havent had this happen to me YET so trying to stay ahead of it.

 

[2001LC]

Fluid should never be above max line at any time. You're really not understanding what has been posted above or is embossed on the brake reservoir. The accumulator charges as needed by demand of pressure sensors, it drawing down the fluid as pump is running. It is designed to do this.

 

[100d ua]

just for clarity, are you replacing just the separated motor or the "motor pump" with the pump head?
i thought on a cold truck, the brake fluid is always above max, and once the truck is turned on, the pump charges the accumulator and thus the brake fluid level goes down to about the max line (if the proper fill procedure is followed as stated on reservoir)?
you are then getting lights and alarms because the pressure sensor is not seeing the accumulator pressure rise to the desired psi?
while the lights and alarms are happening in the driveway at startup, what if you pump the brakes 40 times, does the alarm and lights stop?
in a 'total brake failure" as some have experienced, has anyone pumped the brakes about 20 times in between moments of soiling your underwear as your hurdle down the road with no brakes? isnt that the old trick to build pressure in the system?

again, havent had this happen to me YET so trying to stay ahead of it.

Here is a picture of the tank when I arrived to inspect the vehicle the night the wife called me, with ringing/lights ON. This is with the engine OFF and semi-warmed up as the wife had it on for several minutes while the ringing/lights were going off - this was while we were talking on the phone about the issue she was describing to me.

The picture below is also with the vehicle OFF semi-warmed up as it was driven into the garage after being dropped off in my driveway. The ringing/lights are OFF.

This morning I observed the fluid was above the MAX line like in the first picture, I had a feeling if I turned the key to ACC the motor/pump would start pumping fluid through the accumulator but either get stuck or not pump at all. I watched the fluid drop very slightly before stopping and staying above the MAX line. This is when the lights/ringing went off for a second time since the first time.

This is merely me stating what I have observed throughout this ordeal.

FOR REFERENCE:

Here is the rebuilt motor I purchased:

This looks like the "Booster Pump Motor" in the above diagram.

 

[100d ua]

Fluid should never be above max line at any time. You're really not understanding what has been posted above or is embossed on the brake reservoir. The accumulator charges as needed by demand of pressure sensors, it drawing down the fluid as pump is running. It is designed to do this.

I have not removed or added or made absolutely ANY changes to the fluid in the reservoir.