Short Buzzing / Grinding Noise From Brake Pedal ?

[johnny1964]

Hi all,

got my '98 GS300 last week and there's a short (about 2 seconds) sort of buzzing/grating noise from the brake pedal when braking gently coming to a stop. I can also feel a slight vibration through my foot. It doesn't do it when I stamp on the brakes .... any ideas guys ? getting a bit worried ...

[IHgs300]

Mine does it as well, apparently it's the accumulator for the braking system. These cars don't have a servo like other cars, it's a container full of gas. The buzzing you can hear is pump re-charging.

I.m told as long as it doesn't do it with every press of the pedal it's ok. Have a look here John.

http://www.soarerworld.com/forum/showthread.php?29558-TRC-Accumulator-rebuil

[johnny1964]

Aah thanks IHgs300, I'm taking it to my local garage on Wednesday and it's really helpful to have some knowledge beforehand ...thanks again

John

[IHgs300]

No worries John, please post garage result.

[johnny1964]

Hi IHgs300

Garage did short road test yesterday, mechanic thinks its ABS issue. It's going back in tomorrow to scan for any codes but he doesn't think there'll be any ??...will update when I know more ...

Cheers

[dave1]

Early MK 2 GS had problems with the brake accumulator/pump. Might be an idea to get that checked.

[johnny1964]

Thanks dave1, it's nice to be armed with some know-how..........

[johnny1964]

Update : my garage couldn't find any codes, the car wouldn't 'communicate' with their scanner ? ... however he was 99% sure its an ABS sensor causing the noise and without the code it could be any one of them. The warning light is not on so I was advised to wait until it does then go to a main dealer for diagnostics to identity the faulty one. Quite fed up really because he was saying this won't be cheap... does anyone know a trustworthy independent near the Brighton area ?

Cheers

[dave1]

Are you in RAC/AA ? They may be able to get a code up if you call them out saying that you have a worrying noise on braking so don't feel safe to drive the car

[johnny1964]

Hi again Dave... sadly I'm not a member of either ..

[steve2006]

Lexus vehicles are a bit particular when it comes to OBDII scanners, several members have purchased their own for a reasonable sum which do work, they generally pay for themselves on 1st use when you consider a diagnostic at Lexus will cost you £60.00 plus.

Other members will I'm sure be able to recommend a suitable one.

I once had a faulty ABS sensor and although not on a Lexus the symptoms were the same a grinding noise with a pulsation through the pedal when just about coming to a stop.

The sensors do fail but you really need the code to determine which one, other possible causes are broken or damaged toothed pick up rings on the hubs, a build up of crud (paricularly iron particles) on the sensor pick up head and defective wiring or plug connections.

If the car is breaking normally apart from this problem and there is no ABS warning light I would leave it a little longer to see if the fault develops further.

[johnny1964]

Hey steve2006,

Many thanks for the info. I'm going to wait until the light comes on then hopefully will be able to determine which one needs attention rather than a goose chase.. As you say its not cheap for diagnostics and I will look into getting a scanner after the holidays, I appreciate your help.

Happy Christmas...

[MackScania]

Hi Johnny, did you have any further luck with your issue?

[eXOBeX]

Interesting, I'm getting the same symptom now on my 2002 GS. Almost at a stop and you get the buzz and a slight drop in braking pressure (so you've got to put your foot further down). Due for MOT very soon, will be interesting to see if that picks anything up (besides the borderline emissions check - even on LPG - due to one empty cat and one suspect cat).

[BJ430]

Chances are the MOT wont pick it up if there are no warning lights - this fault is caused by the teeth wearing down on the ABS Sensor/reluctor rings or a dicky sensor - they will need replacing whichever it is.

This has just happened on my GS430 on the rear (both sides) caused by a warped deflector plate grinding down the sensor ring.

Not happy only done 50k

B