PWRSLVE

2005 SC430,160k miles.

Since I bought the car last summer, I’ve had a squeal coming from the passenger side rear brake.

Happens as you gradually press the brake to slow down, only at around 30-35mph. There is a high pitch noise but as you continue to slow down and press the brake firmer, noise is gone.

other things I’ve noticed in trying to get this resolved…

Only happens when brakes have warmed up.
Definitely from rear and definitely only on passenger side.
Only audible if windows or top down.
Once it starts squealing, if I hit the brakes harder than I really would want to for smooth braking, it doesn’t happen.

So far, the car has had….

New pads and rotors resurfaced - didn’t fix it.
New pads, new rotors, new shims - didn’t fix it.
New anti squeal clips, definitely installed correctly - didn’t fix it.

I’m leaning towards it being the caliper since it’s always on the same corner, but I’ve had this looked at by 3 different shops and nobody else thinks the calipers are the issue.

Running out of ideas. Anyone experienced and resolved something similar? Other suggestions?

bmanone

Have you checked the parking brake for noise? Adjustment?

PWRSLVE

Thanks. Certainly worth investigating.

Raven01750

Good call. I was watching this thread because after all the work he had down, I was kind of baffled. I hope they get back to us when they find a resolution.

Paul

PWRSLVE

I will definitely report back. I’ve read through many threads and the only one that described the same symptom on one side after doing the same work on the brakes was resolved with a caliper but the parking brake seems like a relatively simple thing to look into next. After that, not sure what else is left but a caliper.

Wilson2000

A hanging caliper could cause a squeal. Calipers are relatively easy to rebuild.

That said, properly greased shims and caliper pins are of upmost importance to prevent brake squeal.

PWRSLVE

The thing that keeps pointing me towards the rear passenger side caliper is the fact that no matter who has worked on the brakes, the noise is always only on the passenger side rear. Looking at the service records, I suspect the previous owner had the same issue as he had the rear brakes “cleaned” due to noise at a shop about a year before selling it although it doesn’t specify any particular side. I’m determined to resolve this as I really do love the car but this noise really is annoying when the top is down.

DshngDaryl

The SC has a specific bleeding procedure. It is possible the people working on your car did not know this, so the system wasn't bled properly. This is possibly causing your rear passenger caliper to not work right.

iolmaster

iTrader: (1)

Never heard of this. What is different about the SCs procedure than others. I have had my brake fluid changed a number of times at a local shop and never had a problem. And, how would that cause a squealing sound in the caliper?

Wilson2000

Here's a thread that talks about the bleeding procedure:
https://www.clublexus.com/forums/sc4...ake-fluid.html

Here's a YouTube video that shows a 2GS owner upgrading a faulty master cylinder/antilock brake module with a used SC430 unit:

I hope the 2GS conversion fix doesn't make us real SC430 owners incapable of sourcing a used unit if need be! Based on the comments for the video, this is a common problem with the 2GS module, and the SC430 module is the popular fix.

Wilson2000

Just guessing....If you had air trapped in your caliper, upon heating-up it would cause pressure to build, hanging up the piston from retracting, and causing the pad to drag on the rotor.

DshngDaryl

Usually the procedure is to bleed from the caliper farthest from the Brake Fluid Reservoir. That would be the rear right caliper.

As for the actual bleeding procedure, I am hoping our friend @bgw70 will chime in.

Bgw70

the video Wilson posted, post #10, shows the correct bleeding procedure.
the front is bled the conventional way…pump x3, hold & release fluid.
the rear is different…key on, press and hold brake pedal. Release fluid from caliper…the pump does all the work.

PWRSLVE

Quick update. Had an independent Toyota/Lexus shop go over the rears and redo the pads, rotors, squeal clips, etc. but the Issue still persists. Next step is replacing the rear calipers and doing a brake fluid flush next week.

I noticed while crawling around under the rear that the brake hoses are pretty cracked on both sides. Seems like I should get these replaced also. Looking online, seems like front and rear oem hoses are about $200 but StopTech SS lines, I can get both sets for $110. I understand the benefits of stainless steel are negligible / debatable but any reason I should not get the StopTech lines just from a cost point of view?

Wilson2000

I would get the OEM from a Lexus dealer. If you buy OEM online from any other dealer, you're likely getting counterfeit parts. I have no experience with StopTech. I buy Toyota/Lexus vehicles because they use quality parts, which makes them very reliable. I wouldn't risk buying an unknown manufacturer's parts, when true OEM parts are available.