jonny992

okay so I have a huge problem with my brakes. its working fine and all. but recently everytime I press my brakes to a complete stop it will make a thud thud thud sound before stoping

when I release the brakes to move forward again it will make a thud thud sound.

its not a grinding sound. and my pads are still okay. so what could it be.

Spike100

Your description sounds as though you could have a problem with wheel bearings. Also maybe the calipers?

How many miles on your Z?

jonny992

only 57985

I have a fault rear bearing but the thud thud thud sound is from the front

I made this thread about brakes a couple days ago because I thought it was because my pads were worn but I guess that's not whats causing It because they are still good.
https://my350z.com/forum/brakes-and-...orry-caps.html

Spike100

Please forgive me for presenting guesses, but's difficult diagnosing something "long range" and not seeing the offending parts.

I wonder if your rotors are warped? That definitely makes noise.

dkmura

iTrader: (64)

Another question is has the OP checked the amount of brake fluid in the brake master cylinder? When was the last time the brake lines were flushed?

jonny992

never heard of a brake fluid flush. and the brake fluids is half full in the plastic container

FOOKhonda

iTrader: (1)

I'm willing to bet its one or more of your rotors either warped or totally gone. This is the same thing that was happening with my bosses truck, a quick check of the rotors shown he had a rotor that was worse than I've ever seen.

Spike100

Hey jonny, I've owned my Z for 12 years and have never flushed the brake lines, so I'm not sure about this.

Check your rotors, calipers, and wheel bearings. The problem is likely a warped rotor.

kilogram

iTrader: (1)

Something like this should have you either taking the wheel off to diagnose yourself immediately or taking the car in to have it inspected by someone who knows what they're doing.

It sounds like one of the caliper mounting bolts is loose. The clunk would be the caliper moving against the bolt hole on stops and starts. Either way, get off the forum and go get your car checked out, either by doing it yourself or having it towed someplace to be inspected.

MicVelo

^^^ Would definitely concur on getting it diagnosed by a pro IMMEDIATELY.

But as Spike said, long range guesses are hard without putting our hands on it but I'll take a stab at it anyway.

Related to the brake power flush, and since it occurs under braking (and release only) it's possible that one of the pistons in your front brakes is sticking and not engaging/disengaging all the way. The thudding you are hearing/feeling would be - in this scenario - the pad slapping inside the caliper as the rotor turns.

Resolving this usually involves rebuild of the caliper. Not a big deal but it isn't cheap as Alldata (or other diagnostic and repair guide) databases will stipulate the manhours needed for repair and they are somewhat liberal with the time involved for work by an average mechanic. (Plus full retail on parts)

I say that it's related to the power flush in that every couple of years or so, depending on mileage used during the year, the brake system should be flushed and bled. The reasons for this are multi-fold:

1. Brake fluid, despite it being in a "closed system environment" can accumulate moisture - water - in the system and that can affect brake performance negatively in that water does NOT compress like fluid does giving less-than-optimal brake performance.

2. Said moisture in the fluid can lead to corrosion in the calipers, excess of which can cause the above mentioned sticking.

3. And again, while it's a "Closed system", debris and dirt can build up in the hydraulic system - from the master on down to the calipers - in a manner that can affect performance of the brake system. Dirt and debris get in no matter what.... outside contamination (low likelihood but is a factor) and the internal breakdown of seals and o-rings inside also leave residual debris.