Tom999lexs

Hi,

I am desperately trying to fix a strange noise i get whenever i press the brake pedal hard (driving or stationary, even with ignition off). Dealer said bleeding would solve it so i did it myself with techstream (brake actuator removed bleeding procedure). But no air bubbles came out and the noise didn't change at all.

Anybody ever heard the noise (see YouTube link below) and knows the cause/fix?

https://youtube.com/shorts/ic0KUaJKJ6E?feature=share

salimshah

Seems like the source is the movement of the pedal either the hinge or the pass through rubber boot and nothing to do with bleeding.

I would try to isolate or simply lube both locations. Use silicone grease safe for rubber and the key is to use sparingly. The grease is a magnet to attract dirt and grime.

Please please do not reach for wd-40. You can use it to wash off the lubricant and then apply fresh lubricant.

Salim

Tom999lexs

Hi Salim,

Thank you for your message. Unfortunately the noise is coming from inside the brake lines around the reservoir / abs system.

Today i unplugged the 2 connector of the abs unit and tried if the sound was still there but at first sight it didn't.
So i has to do with the abs unit. Buying a new ABS unit will probably solve it but i first want to be sure there aren't any other solutions, even if it is temporarily.
​​​​

salimshah

Use a mechanics stethoscope or screw driver to help transfer source of sound to your ears.

If it is internal to the ABS unit then the solution will be to replace the unit. Should the replacement be done immediately or it can be postponed would be the question. A new unit will come with hefty price and warranty. You can try to source a used one through salvage yards like LKQ.

Salim

Aegean

This is the typical “barking” of the brake actuator of some Lexus/Toyota hybrids. Mine, a 300h is doing that noise maybe once every 50 times I apply the brake and I think when it is a sudden violent braking. Yours sounds much worse.

Correct, air in the system is the reason but also a faulty actuator might introduces air in a system that had no air after bleeding

The brake actuator has an extended warranty for 10 years but they honor it only if you have the specific codes the recall. Diagnostic Trouble Codes (DTCs) C1391, C1252, C1256 or C1253.
I have run health checks with Techstream and no codes are present or in history. Did you had any codes before you bleed it?

Droid13

Yes, sounds like the infamous "bark". Mine had that for years but the brakes always worked without issue, it was just annoying on those occasions it made itself known. Bleeding the brakes was always a first stop "try this" that rarely works long term. The intermediate solution is a complete and thorough brake fluid change (sometimes multiple) which may or may not work long term, and the final solution is to replace brake actuator at significant cost.