Clunk noise when Breaking
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Joined: Jul 2018
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2014 C63 507
Clunk noise when Breaking
2014 507 edition. Just rebuilt my calipers and got them sand blasted then power coated.
Bled the brake lines did a flush and refilled etc.
Now when my car sits for a while I start it up as soon as I start driving the first time I hit the brakes it make a clunk noise just one then doesn’t do it again. Coming from front half of vehicle can’t tell which side.
Also make the same noise occasionally when switching from reverse to drive then hitting break for the first time again.
Dont know what to check first need need some advice.
Thank you
Bled the brake lines did a flush and refilled etc.
Now when my car sits for a while I start it up as soon as I start driving the first time I hit the brakes it make a clunk noise just one then doesn’t do it again. Coming from front half of vehicle can’t tell which side.
Also make the same noise occasionally when switching from reverse to drive then hitting break for the first time again.
Dont know what to check first need need some advice.
Thank you
Thread Starter
Junior Member
Joined: Jul 2018
Posts: 35
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2014 C63 507
I googled it most of it has to do with racing. Basically saying if there’s a gap between the pads and piston you here that noise because the pistons get “knocked back” into the caliper with high g force.
My noise only occurs after my car has been sitting for a hour or more and I start it up drive for a few meters then hit the brakes. Knocks once then that’s it.
Could i I need new pads? Calipers maybe loose? Or an issue with the pistons themselves within the calipers?
My noise only occurs after my car has been sitting for a hour or more and I start it up drive for a few meters then hit the brakes. Knocks once then that’s it.
Could i I need new pads? Calipers maybe loose? Or an issue with the pistons themselves within the calipers?
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2012 C63;1971 280SE 3.5(Sold);2023 EQS 450 SUV 4 Matic (Wife's)
I think you may have introduced a little slop at the ends of the pads by sandblasting and painting your calipers. The pad sticks a little to the rotor while sitting and moves it a bit when you start up. When you hit the brakes it is moving the pad a bit and causing a knock when it seats back into position. Also explains why it knocks a little when you switch from reverse to drive.
Thread Starter
Junior Member
Joined: Jul 2018
Posts: 35
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2014 C63 507
I think you may have introduced a little slop at the ends of the pads by sandblasting and painting your calipers. The pad sticks a little to the rotor while sitting and moves it a bit when you start up. When you hit the brakes it is moving the pad a bit and causing a knock when it seats back into position. Also explains why it knocks a little when you switch from reverse to drive.
MBWorld Fanatic!
Joined: Feb 2010
Posts: 5,649
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2012 C63;1971 280SE 3.5(Sold);2023 EQS 450 SUV 4 Matic (Wife's)
If the problem is slop in the calipers, new pads will not fix the problem as the backing plates will be the same size as your existing pads in length from end to end. You will need to shim the ends of your pads to stock clearances in the caliper. Those surfaces were not painted originally so maybe they didn't sand blast them and they should not have painted those surfaces, that the ends of the pads seat against. You can take the pads out and check the fit in the slots looking for any slop. They should be a snug fit. Also check that all the pistons are moving freely in their bores and the rubber seals are not binding, torn or twisted. Check that the pins are installed properly along with the anti rattle spring bracket and the cross bolt. Check that there is no powder coating interfering with the fit of the pads and clean it up if there is. Once you are sure that the pads are fitting properly, that the caliper is operating properly after the rebuild and that everything is installed properly. If you still have a problem it may be time to visit a brake specialist to see if they can identify something you have missed. Do make sure all related fasteners are reinstalled correctly and torqued to spec as recommended by Cathyname as well.
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From: Jeffreys Bay,South Africa
2012 C63 AMG Coupe
Also make sure that reinforcing bolt in the middle of the front callipers are torqued to spec with Loctite, they provide support for the callipers and you don't want that coming loose at speed and messing your calipers and wheels up.
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Thread Starter
Junior Member
Joined: Jul 2018
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2014 C63 507
Got it fixed!
It was the front right caliper big bolts in the back one of them was loose. Tightened all up cleaned up the pads and rotors while I had it all disassembled
now its all good
It was the front right caliper big bolts in the back one of them was loose. Tightened all up cleaned up the pads and rotors while I had it all disassembled
now its all good
