Popping Sound When Applying The Brakes?

[Sweet95LS400]

Well I have a new issue, just when I thought everything was working perfectly. When I press the brake pedal, I can hear a popping sound. The brakes work fine, no grabbing, pulling or pulsating. The popping doesnt doesnt have any effect on the brakes themselves. The sound only happens when I am stepping on the brake, sometimes it will do it just sitting with the car in park and pressing the brake, sometimes it wont. I checked the fluid level, all is good. The brake pads and rotors were just changed about 4k ago. The fluid was just flushed with the 90k service as well. The sound doesnt occur when hitting bumps or turning or anything else. I just had new ball joints put on as well. Any ideas?

[RFeldes]

How long ago were the ball joints replaced? By whom? And why?

[Sweet95LS400]

They were just replaced about 500 miles ago by my Lexus dealer. It was making this noise before they were replaced, it didnt get any better or worse. The dealer had recommended the lower ball joints be replaced because they had a lot of play in them, so I had them do it.

[Threadcutter]

Well I have a new issue, just when I thought everything was working perfectly. When I press the brake pedal, I can hear a popping sound. The brakes work fine, no grabbing, pulling or pulsating. The popping doesnt doesnt have any effect on the brakes themselves. The sound only happens when I am stepping on the brake, sometimes it will do it just sitting with the car in park and pressing the brake, sometimes it wont. I checked the fluid level, all is good. The brake pads and rotors were just changed about 4k ago. The fluid was just flushed with the 90k service as well. The sound doesnt occur when hitting bumps or turning or anything else. I just had new ball joints put on as well. Any ideas?

Sweet:

With the car in park, open the hood & get the wife/girlfriend to push on the brake pedal while you "listen" for where the noise is coming from. Maybe the master cylinder (against firewall in front of driver) or the ABS module (behind right front headlight assembly). You may have a leaky brake line. Any fluid on the floor?

Also, there may be a "flaky" vacuum line in the system that needs replacement. That would be nice as that's probably the cheapest fix of all.

Have you taken it to an Indie for an opinion? I bet they could find it right quick.

[Sweet95LS400]

I havent tried that yet. There is no fluid leaking out. I park the car in the garage and the floor is always dry. The ABS light hasnt come on and the brakes appear to be working ok.

When I tried listening for the sound, it is a loud clicking sound from outside the car but I cant figure out where it is comming from. I will have to check with my mechanic and have him look at it.

[WJA]

Sweet....

I recently purchased a 2002 LS 430 (67K Miles) from a firend whose had the car since new. I have a very similar "popping" sound and cannot recreate when showing my mechanic. But i have narrowed the source of the sound. It started happening sonn after purchase but did also happen when my friend owned the car. After several inspections by the dealer they said there was nothing wrong. I disagree.

My experience is; it happens when the car is almost to a complete stop. At first the noise came only form the left front wheel area and would happen when the car was in its first few miles. I then felt that the brake pedal pressure was softer than it should be (as compared to my Envoy and Passat) so I activated the emergancy pedal several times and did that for a few weeks thinking that the overall pressure was being compromised becasue my friend rarely ever used the emergancy brake which, I understand helps to keep the brakes adjusted. Well a few weeks later the sound returned but this time from the right front. It sounds almost like the calipers are not fully enaged and at the last moment they fully activate. Then...oddly enough I was getting a pop - pop! The right side would pop and then the left side. That has happend for about two weeks now. Most recently (last few days) it has alternated sides.

My mechanic said sometimes the ABS magnets cause popping at the last second before the car comes to a final stop but he was unable to experience the noise and will not do anything until he knows for sure. I am really interested in your feedback and anyones if this can be pinpointed. Thanks. Vince

[Sweet95LS400]

This is a very good description of the problem. Mine does the exact same thing. I too took it to the mechanic who said they couldnt find anything wrong. I am afraid to wait till it gets worse in fear of the brakes failing, but I dont have much choice. I will keep an eye on the problem and see if it gets worse.

[WJA]

As eluded to before I also think I have too soft of a peddle. But whenI pump the brakes and then quickly pump again, they firm up like I think they should - especially a Lexus. In my uneducated opinion I think the twoissues are related. I was wondering what would happen if I had the brakes bled to assure the pressure is where it is supposed to be.

Your thoughts?

[RFeldes]

WJA......Check the fluid level and if its okay..leave the cap off and push slowly down on the pedal while someone watches the level to see if air escapes or to stop you if it overflows. If that doesn't give you a clue then bleed them.

[Threadcutter]

WJA......Check the fluid level and if its okay..leave the cap off and push slowly down on the pedal while someone watches the level to see if air escapes or to stop you if it overflows. If that doesn't give you a clue then bleed them.

As a side note, I was told by a fairly astute person to always put the little rubber caps back on the brake bleeder stems because they can prevent air from leaking through the bleeder valve into the caliper.

I have no idea as to whether or not this has anything to do with what you are experiencing, but I think it's worth taking a look at.

[Sweet95LS400]

Well I just got the car back from my indie, everything is fine he said. They looked over the whole brake system, said everything is in tip top shape. New fluids, pads, and rotors. Pressure is good and no leaks. So I am lost as to what it can be. Makes me feel good though that everything is A-OK! (For now anyway) I will keep you all updated if I do find something. These boards are a real resource for trying to get help. I really enjoy and value a lot of the feedback and opinions I get on here. Even though I am not a mechanic by any stretch of the word, I have the knowledge and confidence to do some of my own simple maintenance and repairs to save myself some money (and who does it better than yourself right?) and for this I am grateful to you all. Thank you.

[Ross W.]

My car made that noise before I did the brakes (new pads & drilled rotors); what I found was that the backing plate for the for the pad's friction material had become worn where they slide on the caliper. So, when the brakes were applied, the pads would close the gap to the caliper with a loud pop! When I fitted the new brakes, the pads fitted much tighter in the caliper and the noise went away. The dealer found a bad tie-rod end a couple of years ago that made an almost identical noise under the same conditions as the sloppy brake pads. Check out the fit of the brake pads in the calipers, and check the tie-rod ends. Those could be your culprits.

[WJA]

My car made that noise before I did the brakes (new pads & drilled rotors); what I found was that the backing plate for the for the pad's friction material had become worn where they slide on the caliper. So, when the brakes were applied, the pads would close the gap to the caliper with a loud pop! When I fitted the new brakes, the pads fitted much tighter in the caliper and the noise went away. The dealer found a bad tie-rod end a couple of years ago that made an almost identical noise under the same conditions as the sloppy brake pads. Check out the fit of the brake pads in the calipers, and check the tie-rod ends. Those could be your culprits.

Ross,

That's sounds appropriate. I am inclined to go that route. Thanks.

[vip.ls4]

My car made that noise before I did the brakes (new pads & drilled rotors); what I found was that the backing plate for the for the pad's friction material had become worn where they slide on the caliper. So, when the brakes were applied, the pads would close the gap to the caliper with a loud pop! When I fitted the new brakes, the pads fitted much tighter in the caliper and the noise went away. The dealer found a bad tie-rod end a couple of years ago that made an almost identical noise under the same conditions as the sloppy brake pads. Check out the fit of the brake pads in the calipers, and check the tie-rod ends. Those could be your culprits.

Sorry for my ignorance but where exactly are the tie rod ends?

[Ross W.]

Sorry for my ignorance but where exactly are the tie rod ends?

They're just ahead of the muffler bearings.

Just kidding! They connect to the steering arms on the wheel hubs. On the other end, they're connected to the steering rack.

[nc211]

sweet,

i was wondering, any update on your brakes? mine are doing this now too, actually have been for quite some time..

[WJA]

nc211,

Sometime back I received the following reply. I think it is right on. When I contacted Lexus Corporate, they told me to take it to a dealer - well the dealer could not diagnose the issue. This reply is self explanatory. A couple of weeks ago I had rotated my tires and inspected the amount of linig on the pads. There is still plenty but when it gets close to I will replace the pads and have more feedback to respond to Ross's comments that follow. Hope this helps.

Vince

Ross W.

Today, 12:25 PM

Post #12

Club Member

Group: Regular Member

Posts: 38

Joined: 5-April 06

Member No.: 24,684

Car Model:1994 Lexus Ls400

Location:Los Osos, CA

My car made that noise before I did the brakes (new pads & drilled rotors); what I found was that the backing plate for the for the pad's friction material had become worn where they slide on the caliper. So, when the brakes were applied, the pads would close the gap to the caliper with a loud pop! When I fitted the new brakes, the pads fitted much tighter in the caliper and the noise went away. The dealer found a bad tie-rod end a couple of years ago that made an almost identical noise under the same conditions as the sloppy brake pads. Check out the fit of the brake pads in the calipers, and check the tie-rod ends. Those could be your culprits.

[sweetls]

Another thing to take in to consideration is the Lexus brake pad shim kit. If you did the brakes or had an indi do it, it is possible the shim kit was not installed resulting in a popping sound while applying the brake. Just a thought.

[WJA]

Another thing to take in to consideration is the Lexus brake pad shim kit. If you did the brakes or had an indi do it, it is possible the shim kit was not installed resulting in a popping sound while applying the brake. Just a thought.

Sweetls,

Can you purchase a brakie pad shim kit separately or does it just come with the pads when replacing?

[LScott400]

Brake hardware bulletin attached.

lbr00295.pdf

[WJA]

Brake hardware bulletin attached.

Scott,

Thank you for the bulletin. This is very helpful to understand what is causing the problem that has been around for many years.

WJA

[nc211]

thanks fellas for the replies!! I'm 100% positive it is the shim kits on the front rotors. I do have new oem pads, and new oem fitment and shim kits on all of the wheels. They probably have 5k miles on them. I have Mountain rotors on the front, and cheapo Napa's on the back. The popping noise is only coming from the driver's front....which just so happens to be the same one that screams when going in reverse. I noticed a few weeks ago when I went back in to regrease the shims, and skuff up the pads on the driveway "in an attempt to kill the noise" that on the driver's side, front, the thin black coating on the outside shim "where the piston hits" is torn, and bunched up on one side. So I think this is the problem. My next question however, is how did that happen to a set of brand new shims? I'm thinking maybe a caliper rebuilding kit is needed, because the piston isn't hitting the pad squarly?

Threadcutter, you've done the brake rebuild kit process before right? Do you know if there is an actual kit I can buy from Lexus for this, or a specific part # (s) that are needed?

I'm getting close to building the work bench in my new garage, and should have some space to get the cars in soon. On the top of my list, is a few neglected maintence items that need to be done. One is to replace my plugs "Blake, still got em' amigo ;) ", the ASUS bushing replacement on the lower rear control arm, inner tie rods, wires, caps, etc.... And, a full brake job.