Pump the brakes during the first 30 seconds after a coldstart. This loads the booster & should keep it going without having to replace.
Last edited:
Screeching from brake Master Cylinder assembly
- Thread starter Weeniewheeler
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
Pump the brakes during the first 30 seconds after a coldstart. This loads the booster & should keep it going without having to replace.
This is what I bought that didn't solve anything. 98-07 LEXUS LX470 Toyota LAND CRUISER ABS ANTI-LOCK PUMP Motor/actuator Rebuilt | eBay
This is the noise I get even after replacing the booster pump motor.
Last edited:
I also have an ABS light error 56 on my new to me LX470 184K for $2.5K. first, I am going to try bleeding all the brakes as per recommended procedure since that has solved it for some people. Brake flush was done at 120K supposedly, but car sat still for 4 years since 2010. Fluid doesn't look clean. So with the hygroscopic tendencies of brake fluid it probably would be a good idea for me to flush the system.
One of the research topics I had found was that on the SC400/SC300/LS400 the rubber hose that goes into the accumulator gets damaged inside and flakes small debris into the accumulator causing damage. I am still new to LX/LC so have to see if this is also pertinent on 4.7 vehicles. If so, I would recommend that folks replace that hose as part of the R&R of the accumulator motor.
One of the research topics I had found was that on the SC400/SC300/LS400 the rubber hose that goes into the accumulator gets damaged inside and flakes small debris into the accumulator causing damage. I am still new to LX/LC so have to see if this is also pertinent on 4.7 vehicles. If so, I would recommend that folks replace that hose as part of the R&R of the accumulator motor.
Did anyone here have any luck? I'm getting the same noise with all the lights on the dash.
Pretty sure PO had the MC changed, but my motor and accumulator are original so I think I'll start there. Hoping it helps.
Pretty sure PO had the MC changed, but my motor and accumulator are original so I think I'll start there. Hoping it helps.
Still no solution for me. I have replaced accumulator and pump with rebuilt ones, and rebuilt MC. I also flushed and replaced brake fluid.
Weird
Do your brakes work otherwise? I just drove mine around the block and it stops on a dime. However my ears are ringing from the alarm.
Yes, brakes work great and mine doesn't go in to alarm yet at least.
If anyone needs a used brake booster with accumulator or used master cylinder, send me a PM. Both are working. Would be good parts to throw in now to save money or rebuild and hold onto for a back up. I will make you a deal plus I need to clear some space in the garage.
Besides the new screeching sound (NOT the wife this time), my ABS and Brake light came on, in addition to the audible dash alarm. On New Year's Eve, of course. As I am mechanically declined, I took my truck to Ryan at OTRAMM (Northern-ish Virginia) and had him check out the codes. He found problems with the ABS solenoid, the pump motor and more. He replaced the whole assembly new (not cheap), but now I won't have to worry about if for another 295k.
I have this issue also. The problem is the high pressure switch in the master cylinder. This pressure switch is built into the master cylinder so it cannot be changed on its own. You have to get a new master cylinder.
What is happening is the booster pump has two control switches - low and high. The pump starts when the low pressure switch and stops with the high pressure switch. The high pressure switch is flaky. Mine needs to cycle a few times when it is cold. To cycle the switch, you can pump/ press the brake pedal until you hear the pump running. If you have the engine, radio and hvac off, you can hear the pump from the drivers seat. Do not let the pump run more than 5 minutes or you will have a fault. Cycle the key and try again.
I have tried rebuilding the master, flush the brake fluid and change the pump and accumulator and none of it worked.
What is happening is the booster pump has two control switches - low and high. The pump starts when the low pressure switch and stops with the high pressure switch. The high pressure switch is flaky. Mine needs to cycle a few times when it is cold. To cycle the switch, you can pump/ press the brake pedal until you hear the pump running. If you have the engine, radio and hvac off, you can hear the pump from the drivers seat. Do not let the pump run more than 5 minutes or you will have a fault. Cycle the key and try again.
I have tried rebuilding the master, flush the brake fluid and change the pump and accumulator and none of it worked.
When a drop of water gets in the wiring harness from a leaky windscreen/roof rack bolts, it runs down the harness and possibly ends up in the ABS ecu connector. With a pin or 2 shorted out by a drop of water, the pump can keep running simulating HP switch fault, what the drop of water was doing was it was keeping the motor running. This happened to me so I pulled the ABS connector from the side of the M/C module and drove around for a week with A/C on full as well as heat on full to dry out air in cabin. Shoved it back on a week later, no more probs.
Looks like i am next in line with the issue. Along side the intermitent noise, i also see the fluid squirt into the ceiling of the fluid bottle, right at the same time when the noise occurs. So the damage is 2.5k and labor??? Sigh...
Looks like I found some original threads on the issue in here. After researching a bit i found out that the whole assembly can be had for $1823 apparently. Should I only spend $450 on the motor, go for $975 for motor and accumulator, or go full throttle on the whole master assembly. Thoughts appreciated.
Cheers
Cheers
