430sc brake/electrical problem

[Penny]

Noise from brake pump area and coupled with several  dash lights now showing

I can also feel the red pipe into the ABS pump pulsing when the engine is running

 

Any ideas on what is wrong with this  52 plate car ?

[ColinBarber]

It could be the booster pump or accumulator not getting to the correct pressure but could be something simple such as the pressure sensor. You really need to get the error code(s) to give you a starting point.

[Penny]

Can you tell me Colin if you can hear your pump motor running continuously

with just the ignition and engine not running.

My pump motor runs for a few seconds then switches off.....it does this cycle with the ign key on first position - ie not engine running.

 

U-tube video mentions the pump motor commutator wear can possibly give this pulsing and shows how to rebuild with new brushes etc

[Penny]

On 7/25/2021 at 11:27 AM, ColinBarber said:

 You really need to get the error code(s) to give you a starting point.

Fault codes

C1223        C1252       C1256

Has anyone else had this problem and what was the repairs needed?

[ColinBarber]

C1252 means the motor is running for too long (trying to build up pressure), and C1256 that the pressure doesn't build up correctly.

Either you have a faulty motor, leak in the pressure accumulator or the pressure switch is faulty - probably in that order of likelihood. 

 

It should be possible for the pressure switch to be removed and external pressure applied to the system to see if there is a leak, and the pressure switch itself can be tested.

Brushes worn on the motor is a distinct possibility given the age or the vehicle, they must have worn down quite a bit over the years.

 

Many people when they get a fault like this they swap out the complete brake master cylinder/motor/accumulator unit with one from a salvaged car - the issue is that you don't know how much life that replacement has in it so repairing the motor would be good to do if you can find someone to do it. 

[Penny]

Only $65 for this kit........but that works out to $200 with shipping and taxes

Chap on the UK bay does replacement motor rebuilds

You mention "It should be possible for the pressure switch to be removed and external pressure applied to the system".....can you give details please before I decide to pull out the unit. 

[Penny]

and this is what I hear on mine....

 

As Michael Cain once said " Not many people know that "

http://www.diy-time.com/automotive/toyota/faulty-brake-actuator-brake-booster-pump-on-toyota-lexus-cars/

[Penny]

No more noise

[PeterT]

I have same problem, no fault codes showing have swapped discs, pads and actuator rings and made no difference. Would appreciate some guidance