help, clunk when braking in reverse

[redlightrich]

hi all, i have a clunk noise when applying the brakes in reverse after driving forward. it only does it the first time i brake while in reverse, like backing out of a spot. if i brake several times while pulling out, it is always normal after the first application. i recently changed my wheels and tires and checked the calipers, as i noticed this problem prior to changing them. nothing seemed loose. i also checked suspension components quickly, looking for something obvious, but found nothing. this never occurs while driving forward, which helps me "forget" the problem. my car is a 97 gts with under 5k on it. this is going on for about 900 miles, and i am starting to feel like i am pushing my luck. thanks for any help or advice, rich.

 

[SingleMalt]

Well, I've witnessed this on many-a-Viper. I believe it's quite normal. If anyone has other opinions, I sure would be interested too.

Mike

 

[BillS]

I too had a 97 GTS with the same problem. The noise was coming from the drivers rear wheel area. After checking that corner out all I found was that the brake pad had some slop in the direction of rotor rotation. I never got a chance to try a fix as I totaled the car. It also could be that your rotor has the same problem. My replacement 97 GTS Viper has never had the problem, even with several brake upgrades.

 

[Tom F&L GoR]

The rear calipers are attached to the knuckle with two bolts. The larger bolt goes through a steel "slide" or "bush" that is machine fit to a hole through the casting of the caliper. This allows the caliper to slide inboard and outboard directions but is held perpendicular to the rotor. The slide is greased and the grease is protected by a rubber accordian boot at each end of the slide. If the grease dries out, it becomes "sticky" and the caliper will take a set when braking in one direction and snap over to the other when reversing.

The other attaching bolt is smaller, and rides in a smaller metal tube "slide" that is not greased; there is a nylon/teflon liner to provide a slippery surface. Again, this can become dry and sticky.

You can try removing the wheel, removing the pads, remove the rotor, then see how easy it is to push the caliper in and out along the slides. It should be an easy two-hand deal. If one pad wears more than the other, this may also be the cause.

 

[SingleMalt]

Tom -- One of these days I'm going to come up there and meet you in person. You're the coolest!

Mike

The rear calipers are attached to the knuckle with two bolts. The larger bolt goes through a steel "slide" or "bush" that is machine fit to a hole through the casting of the caliper. This allows the caliper to slide inboard and outboard directions but is held perpendicular to the rotor. The slide is greased and the grease is protected by a rubber accordian boot at each end of the slide. If the grease dries out, it becomes "sticky" and the caliper will take a set when braking in one direction and snap over to the other when reversing.

The other attaching bolt is smaller, and rides in a smaller metal tube "slide" that is not greased; there is a nylon/teflon liner to provide a slippery surface. Again, this can become dry and sticky.

You can try removing the wheel, removing the pads, remove the rotor, then see how easy it is to push the caliper in and out along the slides. It should be an easy two-hand deal. If one pad wears more than the other, this may also be the cause.

 

[SteveMat]

I have a TSB on this printed out at home (for 97's at least).