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New front brakes with grapping noise when shifting to reverse for drive
Hi,
I have just replaced my 2007 RX350's front AND rear brakes with new rotors and pads. The pads I got from the dealer. The rotors I got from Amazon but with good quality. I notice that when I shift my car, with the brake peddle pressed, to drive or reserve, the car of course moves forward or reserses. But with the brake peddle pressed, the car makes grapping/structural noise, because the brakes are applied.
So, could it be the rotors not cleaned? I know the mechnic did clean the new rotors with brake cleaner before putthing them on. Is there anything I can do to quiet the noise?
Brake pads have to be "broken in" to "bond' with the rotor to get the proper grip. The noise you're hearing could be the pads not getting a good "grip" or grab on the rotor surface.
Also, new pads have sharp corners on them that prevent them from sitting perfectly flat on the rotor surface which also is ameliorated with the break-in process.
If the rotors were cleaned off and the pad surfaces were clean of oil/grease when installed, try a couple of semi-hard-braking stops to generate some heat.
Or, just drive normally and see if the brakes improve over the next 50 miles with normal use.
Brake pads have to be "broken in" to "bond' with the rotor to get the proper grip. The noise you're hearing could be the pads not getting a good "grip" or grab on the rotor surface.
Also, new pads have sharp corners on them that prevent them from sitting perfectly flat on the rotor surface which also is ameliorated with the break-in process.
If the rotors were cleaned off and the pad surfaces were clean of oil/grease when installed, try a couple of semi-hard-braking stops to generate some heat.
Or, just drive normally and see if the brakes improve over the next 50 miles with normal use.
Thanks! I have a feeling that the lousy mechanic had grease on his fingers after lubing the caliper pins and then touched the surfaces of the rotors when he put them on. I'll clean the rotors with brake cleaner on both sides of each rotor, and see if that helps.
Thanks! I have a feeling that the lousy mechanic had grease on his fingers after lubing the caliper pins and then touched the surfaces of the rotors when he put them on. I'll clean the rotors with brake cleaner on both sides of each rotor, and see if that helps.
I'd think before laying blame on the mechanic, did you burnish/break it the pads to the rotors? 7-8 stops from 50-20mph & then down the freeway to cool the brakes. During the process you don't want hot pad laying in one stop on the rotor as at stops. After cooling the brakes w/ 3-5 miles of a constant speed, no stops. Go home & park it & let the brakes cool.
I'd think before laying blame on the mechanic, did you burnish/break it the pads to the rotors? 7-8 stops from 50-20mph & then down the freeway to cool the brakes. During the process you don't want hot pad laying in one stop on the rotor as at stops. After cooling the brakes w/ 3-5 miles of a constant speed, no stops. Go home & park it & let the brakes cool.
Thanks for the response. I've been driving nearly 1000 miles on the highway already :-) I know the mechanic absent-mindedly touched the surface with greasy gloves he wore. I saw a line of grease on one of the rotors. I sprayed all the rotors with brake cleaners top-down and that seems to help.
I reread your original thread, & you mentioned when shifting from reverse to drive w/ the brakes applied the vehicle is making a structural kinda noise, That to me sounds like the pads/rotors we're burnished/heat cycled . And you mentioned the tech didn't have clean gloves w/ possible grease when handling the rotors, Which would make the pad/rotor less grabby, slicker. What brand rotors did you get? And I take it the pads are organic? Reason I ask is, I redid the brakes after using a auto parts house brand, rotors/pads. Warrantied those for a pr of Bosch rotors w/ Wagner oex pads. The rotors came in plastic bags, which are zinc coated, & it mentions no cleaning needed, even thou I lightly sprayed them down w/ brake clean.
I reread your original thread, & you mentioned when shifting from reverse to drive w/ the brakes applied the vehicle is making a structural kinda noise, That to me sounds like the pads/rotors we're burnished/heat cycled . And you mentioned the tech didn't have clean gloves w/ possible grease when handling the rotors, Which would make the pad/rotor less grabby, slicker. What brand rotors did you get? And I take it the pads are organic? Reason I ask is, I redid the brakes after using a auto parts house brand, rotors/pads. Warrantied those for a pr of Bosch rotors w/ Wagner oex pads. The rotors came in plastic bags, which are zinc coated, & it mentions no cleaning needed, even thou I lightly sprayed them down w/ brake clean.
I used the pads from the dealer. But the rotors are from Amazon.
Could you please expand on "the pads/rotors we're burnished/heat cycled"? I don't quite understand it. It seems to be better now with some brake cleaner sprayed on.
Could you please expand on "the pads/rotors we're burnished/heat cycled"? I don't quite understand it. It seems to be better now with some brake cleaner sprayed on.
A few quick slow downs....about 8 50mph to 20mph one after the other & then a quick freeway drive a few miles to cool the brakes. With new pads & or rotors, the two friction materials (rotors & pads) need to be heat cycled or otherwise you'll have what ppl commonly call glazing......As I mentioned on another thread, two types of friction....Abrasive friction, which is the breaking of the bonds between the rotors/pads thru the use of the brakes. Adherent/adhesive, which forms a very thin transfer layer of the pad material to the rotor surface, which ppl commonly call ''warped rotors'' as the caliper piston slides in/out which is felt thru the pedal....The abrasive friction depends on the pad material make up as well as the size of the pad, the type of caliper & pad/rotor sizing. The same can also be said about adherent friction as well w/ all else being the same, but the size of the brakes...Such as upgrading to gen3 pads/rotors as well as a couple reman gen3 calipers as well as swapping out the oem brake hoses for a set of ss hoses & flushing out the system w/ new dot3 fluid. One look at a set of #1005 pads & #1324 pads, as well as going to a two piston caliper, 12.6'' vs 12.9'' rotors. The pads/rotors are pretty much awash, you'd be out $100.-$170. for a pr of reman gen3 calipers. The 4200 lbs weight of these rx's, kinda surprised Toyota didn't at least gone w/ a two piston caliper setup. If this was a performance vehicle, I'd go w/ the Stoptech bbk which is a 4 piston caliper w/ a 2 piece rotor setup. I've used http://baer.com 4 & 6 piston calipers w/ 13'' & 14'' two piece rotors on a few vehicles.
Could it be the anti rattle clips on the end of one side of each pad on the front brakes are missing, damaged or installed backwards? Directional changes in Toyota/Lexus vehicles does produce a light click noise, when the brake is applied after a direction change.Maybe one fell off and it’s allowing exaggerated pad movement?
A few quick slow downs....about 8 50mph to 20mph one after the other & then a quick freeway drive a few miles to cool the brakes. With new pads & or rotors, the two friction materials (rotors & pads) need to be heat cycled or otherwise you'll have what ppl commonly call glazing......As I mentioned on another thread, two types of friction....Abrasive friction, which is the breaking of the bonds between the rotors/pads thru the use of the brakes. Adherent/adhesive, which forms a very thin transfer layer of the pad material to the rotor surface, which ppl commonly call ''warped rotors'' as the caliper piston slides in/out which is felt thru the pedal....The abrasive friction depends on the pad material make up as well as the size of the pad, the type of caliper & pad/rotor sizing. The same can also be said about adherent friction as well w/ all else being the same, but the size of the brakes...Such as upgrading to gen3 pads/rotors as well as a couple reman gen3 calipers as well as swapping out the oem brake hoses for a set of ss hoses & flushing out the system w/ new dot3 fluid. One look at a set of #1005 pads & #1324 pads, as well as going to a two piston caliper, 12.6'' vs 12.9'' rotors. The pads/rotors are pretty much awash, you'd be out $100.-$170. for a pr of reman gen3 calipers. The 4200 lbs weight of these rx's, kinda surprised Toyota didn't at least gone w/ a two piston caliper setup. If this was a performance vehicle, I'd go w/ the Stoptech bbk which is a 4 piston caliper w/ a 2 piece rotor setup. I've used http://baer.com 4 & 6 piston calipers w/ 13'' & 14'' two piece rotors on a few vehicles.
Could it be the anti rattle clips on the end of one side of each pad on the front brakes are missing, damaged or installed backwards? Directional changes in Toyota/Lexus vehicles does produce a light click noise, when the brake is applied after a direction change.Maybe one fell off and it’s allowing exaggerated pad movement?
Oh, dude! Don't scare me! :-) I am fairly sure it's NOT the rattle clips that are not missing, but, with mechanics nowadays, I am hoping the clips are not installed backward! It would be hard to install backward, right, since the clips only fit one way?
The anti rattle clip mounted to the side of each pad is transferred from the original pad, they must be oriented towards the top of the caliper bracket. It is possible to either mis-install the clips or accidentally discard them. I’ll include a pic of mine, I just did the front brakes on mine with Lexus parts, pads and rotors.
[img]blob:https://www.clublexus.com/d9966cd8-dfad-4c9c-af64-e1dea1bd5dff[/img]
I went out and checked all the rear and front pads and that they all have proper clips. Below is one of front wheels. And that's not a crack on the pad. It's the grease along the line of the metal clip that covers the pad, which is genuine 2007 Lexus RX350 dealer part, as it has purple color.
04-05-21, 07:42 PM
New front brakes with grapping noise when shifting to reverse for drive
