patbowen

Hello. Recently, my brakes starting making a "thud" sound when I am turning the steering wheel while applying the brakes. I've never had this sound in the 25 years I've owned my LS400. Is this possibly related to the Anti-lock Braking System. All feedback is appreciated.

Also, what replacement pads, rotors, etc, do you recommend and where do I buy them. Thank you.

CLLEXUSS

I could be anti-lock I suppose. The caliper on the front has two pistons that press on the brake shoe. If one of the pistons get's stuck or fails, you're going to get some funky sounds coming out of it because it's now sort of pressing on one side of the pad as opposed to being evenly distributed pressure. It kind of binds on all the seating areas that the brakes shoes are housed in. I'm not saying that's what it is but it could be. For best results with pads oem is best.
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GoldStar

A "thud" to me sounds like worn out suspension bushings

400fanboy

Is it a repeating thud, that continues while you're on the brakes? Then it's something rotational? Maybe something with the caliper.

Or does it only happen once or twice when the gee-forces of the deceleration first affect the vehicle. Then it's strut rods or ball joints, probably.

My money is on the latter.

patbowen

thank you. I hadn't thought about suspension bushings.

patbowen

Hmmnn, I need to pay more attention when it happens to identify if its brakes, calipers, strut rods, or ball joints. Thanks so much.

patbowen

thank you for this insight on the calipers. A lot for me to investigate.

Gerf

Second vote for strut rod bushings ^. I had my 96 for 20 yrs and had the same thing happen before I sold it...try nailing the brakes while someone is watching the front wheels and see if the tire moves forward when it thuds.

400fanboy

The ball joints, on my car, made the steering column come loose. I had maybe 1\16th of vertical play, and it would make noise and move as you were driving down the road. And I'd hear dull thuds\chattering when going over bumps, especially expansion joints on the highway or seam strips between pavement types. The front of the car felt nervous as hell, there was more body roll. The car would get blown around in the wind regularly and was very susceptible to tramlignining in the grooves of the road.

Lower ball joints improved or fixed all of that. They really make a big difference in how tight the car feels.

However: They didn't make noise at low speed, when turning. If you go 5mph and stand on the brakes, and you hear a dull thud, that's gonna be the strut bars.

CLLEXUSS

If you want to try something that doesn't cost you any money per-se, take the brake pads off the side you hear the sound coming from, clean and lubricate the pads and pins and designated areas. Then put them back on, if you notice a considerable improvement or it went away then you know where the problem is or where it isn't. And also when you get the brake pads off, look for uneven wear, if the pad or pads are worn uneven that's a sure sign of a caliper problem which would require a replacement or rebuilt brake caliper. The image is just a sample image, not the actual caliper of course.