Add me to the brake failure list.
2001 LX470. 238k miles. 83k of them by me. Doubt this rig has ever left the pavement. Spent most of its life in Dallas/Houston. Drove 325 miles round trip (Houston to Austin) on Saturday. No issues. The next morning as I’m backing out of my driveway: solid, audible tone; ABS light, Brake light, other lights and no brakes. I wasn’t stomping on the pedal, but solid pressure was not enough to stop the vehicle in reverse. Should have pulled the -brake. Instead just slammed the shifter into Park. Was going less than 5 MPH. Vehicle stopped. Didn’t have much time to react. My urban-area driveway is ultra short. I was only a couple seconds away from backing into my neighbor’s S600 that was parked on the street.
Will be towed to indie shop tomorrow. This thread has been a great resource.
2001LC-
1. You are welcome to my old parts when they come off.
2. The brake fluid has not been overfilled on my watch. I’m familiar with the filling procedure. Current fluid level is about 3/4 full if the Min line = empty and Max line = full. Pressing the pedal 40 times results in no change in fluid level or pedal feel.
Just checked. No sound from booster pump. Not sure exactly what it’s supposed to sound like, but didn’t hear anything of note after turning the key to ON.
Good info, 2001LC. Definitely no noise right now. I had the hood open and the driver’s window down.
On the topic of noise though...
As long as I have owned this vehicle, I’ve always heard a low level humming/mechanical type noise whenever the engine is off and the key is on. Never stopped on it’s own. The noise wasn’t loud or bothersome, but I always noticed it. Just loud enough to know something is running. Not noticeable with the engine running.
On the topic of leaks...
Installed new pads, rotors and brake fluid upon acquiring the vehicle. Never found a fluid leak, but got the low fluid brake light a handful of times over a couple of years. Did the 40 pedal presses and filled the reservoir to Max line each time. Then the fluid level held. Haven’t had to top it off in years. Haven’t done any other brake maintenance since either.
My brakes are fixed.
OEM Brake Booster Pump Assembly - $1,004
Charge for Expedited Delivery - $163 (otherwise dealer said 10-12 days)
Brake Fluid - $5
Installation - $225 (Indie shop)
Sales Tax - $83
Total Repair Cost - $1,480
Plus another $102 to have vehicle towed to the shop.
The codes that appeared were: C1223, C1251, C1252, and C1256.
There was no corrosion on the electrical wire or connection.
I have the old part in hand if you want to take a look at it, 2001LC. Just tell me where to send it.
2001 LX470 with 238k miles.
Local Lexus dealer in Houston. That’s the list price. You may be confusing this pump+accumulator+wire assembly for the larger assembly that includes the master cylinder, reservoir, etc.
Brake booster assembly failure 01LX 238K. 83K since last brake service of any kind other than topping a handful of times..
@bpe3 I had a chance to inspect and pull your booster assembly apart. My conclusion based on inspect booster assemble, your stated history of brakes system and service history and your account of what happens during and after failure:
First, replacing booster assemble was a very good call.
I’m sure you had a leak:
Likely leak started ~83K miles ago when you purchased and serviced the brakes. Leak was indicated by your statements. No info on history to draw any conclusion before this time. Likely Motor ran much more often than it would have otherwise, for a longer run times than designed for (2 minute max). This reduced life of motor. It also caused internal damage to armature rubber insulator of booster motor and possible rear seal of pump.
Motor may have stop running due to wet debris ( brake fluid soaked rubber insulator material) interfering with current flow within motor, by getting between brushes and commutator or brush wire at stop. Motor is working at this time. But commutator and bushes are worn much more than I’d expect to see given your mileage and the history you’ve revealed. I do not consider this motor or pump reusable or rebuild able.
Your $225 for install and only $5 charge for brake fluid at and INDY shop. That is cheap! May indicates they did not pull master brake assemble from vehicle. That they R&R the booster assemble in place, which is fine. This means they can get away with only putting a small amount of brake fluid in reservoir and may not have bleed or flushed brake system, which by stated history is way overdue. To flush a system takes much more than $5 of even the cheapest brake fluid.
Recommendation:
Test booster run time after evacuating accumulator (Topping procedure). Make sure motor stop in less than 40 seconds.
Verify that brake system was flushed and bleed. Not only by asking the INDY shop. But also bleed off a little brake fluid from bleeder of each caliper. Inspect color. Is it fresh (clear) like new or old (dark)? Note some murkiness is to be expected unless a supper flushing was done. Reason caliper piston area is very hard to effectively flush without special procedure (super flush). So some old fluid is mixed in caliper most times. So first little amount may be murky. But then clear up as fluid draws from lines.
Flush and bleed if any signs not recently done. (Dark fluid)
FSM Torque on bleeder is 8ft-lbf. I use 10ft-lbf up to 12ft-lbf on used bleeders.
Top and Test booster motor run time again. Make sure still less than 40 seconds. Over 40 most times indicate leak or air in system.
Make sure to blow brake fluid out of bleeders and that all bleeder have good rubber caps on them.
Note: I use high pressure compressed air, then WD40, than HP air again to blow out bleeders.
Rubber from armature. Brake fluid and heat may have broken down rubber wrapping armature..
This may have been a secondary leak that was more recent. Drawing small amounts of brake fliud only while motor running into the motor, damage rubber insulator of armature.