front brake thumping noise

[Russell]

Just changed my front rotors (Brembos) this weekend. I reused my raybestos ceramic QS pads as they had almost no wear.

However, on my way to work this morning I get a thumping noise in the right front area when I brake moderatly but not during light braking. Did not notice when I did a short low speed. Perhaps the old pads are just adjusting to the new rotor.

No opportunity to look at until i get home. Any thoughts? TIA

[Russell]

Thanks. I checked the right front this evening and could find no apparent problem. Wonder if they just need to seat a bit. I will drive it tommorrow and see. I may check the driver's if no change.

[repenttokyo]

i ordered 2 brembos in feb. one of them was warped right out of the box, took a while to figure out the disc was the problem. examine the disc to make sure it's actually good.

[Russell]

good point, I may have it checked out. However, severe warping would seem to make the car shake/shiiimy etc. Not so here. Just a thumping-almost like abs. NO abs light

[whiskychaser]

Just changed my front rotors (Brembos) this weekend. I reused my raybestos ceramic QS pads as they had almost no wear.

However, on my way to work this morning I get a thumping noise in the right front area when I brake moderatly but not during light braking. Did not notice when I did a short low speed. Perhaps the old pads are just adjusting to the new rotor.

No opportunity to look at until i get home. Any thoughts? TIA
No offence but I would never, ever put used brake pads back in with new discs. Now that I got that old man stuff out of the way - did you feel any movement in the brake pedal? Sounds very much like the pads are moving about at will. Is it possible the new disc isnt on 'straight' or, as has been suggested, its faulty?

[Russell]

I may have an ABS problem.The thumping feels just like the ABS kicking on. I also noticed my ABS dash light does not come on. May be burnt out bulb. Unfortunately I know nothing about the ABS system and my Bentley is of no help. This is all not a good thing.

[Rus]

Russell,

When I replaced my brakes for the first time, I used the same combination as you. Brembo rotors and Raybestos QS pads. Ended up with the same thumping sound and also experienced a shudder from the right front wheel. The symptoms went away with time (less than 100 miles) but the rotors were warped less than 10K miles later. I replaced the rotors (and kept my nearly new pads with a ton of life on them) with Raybestos rotors. I was pleased to discover that the rotors I got came with a painted hub and edge. No noises or warping with new rotors. Pads seated just fine and the brakes sure make the ABS work its butt off to keep them rolling in panic stops. I'm going to stay away from Brembo rotors for these cars from now on. Perhaps you and I got some bad rotors.

P.S.: I drove my car normally after the rotor change fearing that I might warp the rotors by doing a break in on them. I did a break in on the first set and those ended up thumping and warped, so I was afraid it would happen again.

[Russell]

These pads were very even and had very little wear. Thought I would give them a try. Do not think I felt the thumping through the brake pedal.

Someone has suggested really brake hard a few time to bed the pads in??

[Russell]

sounds exaclty what I have going on. Perhaps I somehow damaged an abs sensor ???

[whiskychaser]

These pads were very even and had very little wear. Thought I would give them a try. Do not think I felt the thumping through the brake pedal.

Someone has suggested really brake hard a few time to bed the pads in??
If the pads looked like they had worn at an odd angle I'm sure you would not have put them in. You would def know it if the peddle was going up and down:) Hitting the brakes hard really cant bed in the brakes-everyone says brake gently till they bed in. If you are using the same pads and set-up, the only thing thats changed is the discs. They have got to be duff or not seated properly havent they?

[Rus]

Just like you, I tore the brakes apart when i discovered the strange thumping. Found no problem. When I was replacing rotors, I noted an uneven distribution of pad material on the rotor, which may have cause the thumping originally. Just my $.02

[Bellicose Right Winger]

Interesting...... I'm chasing the same problem in my '93 525i. I cut the Balo rotors to fix a shimmy and also re-used the QS pads. RF thumping seems to occur once per wheel revolution and only under moderate to heavy braking. I've degreased rotor and pads w/o success. Next step is to check rotor for runout and uniform thickness. I'm fairly certain thump didn't exist before I cut rotors.....braking shimmy was main problem. I've re-used brake pads many times w/o any difficulty.

Paul S
BMW CCA 69606