I have a popping soud in my front end on the driver's side. It occurs when I back up the car and hit the brakes. It will also occur going forward the first time I apply the brakes after having backed up, then it will not do it again going forward until after I have backed up the car. The suspension components are in excellent shape and the brake calipers are tight. I need suggestions on what else to check out. This is a 1972 Chevelle SS 402 car with power steering.

Thanks

sounds (no pun intended) like to me you have a pad thats either not installed correctly or the brads are lose that hold the pad to the backing plate.

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71 SS-454 El Camino

Make sure the upper control arm cross-shaft bolts are good and tight. This also sounds like worn out control arm bushings, but you said the components are in good condition. So check the nuts on the cross-shaft.

Had a similiar noise in the 69, it was the disc brake caliper bracket bolts. Not the caliper bolts, the big ones that hold the caliper bracket to the knuckle. Put a wrench on it, if it moves, that's the problem.

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Check all your bolts and bushing d up front....I had the same problem in the rear and it was the uppre control arm bolts....LOOSE.....

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'70 Chevelle ZZ502/600HP
Silverstone Metallic


1989 Corvette 350/240HP.
Artic White.

Guys,

Thanks for your insight. The nuts that hold the control arm to the frame on that side were loose. I still get the popping sound after tightening them. I did check every fastener on the suspension for tightness, including the disc brake braket. All others were tight. I'll keep digging. Ayn other thoughts would be appreciated.

with those bolts being loose, did any of your alignment shims fall out? there will still be play in that arm if they did.JIMK

Are you sure that the front coil spring is seated properly? If it's not, it will make that noise, almost a "bang", whenever the brakes are applied after traveling in the opposite direction.

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MalibuJerry350
TC Member #1279
Original owner '70 Chevelle.
580,000+ miles on car.
Hey, if it's got wheels, DRIVE IT!
My Chevelle: http://hometown.aol.com/erie614/myhomepage/index.html

Yes, I am suspicious that one of the shims on the front bolt may have fallen out. I did tighten the nut all the way down. Would there still be play with it tight? I guess I'll have to take it in to an alignment shop and have it reset. The coil spring is seated properly.

thanks

A few years ago, I had exactly the same problem on my '71 Camaro. I finally found that the brakepads were just a tad too small for the calipers (or maybe the calipers were a bit worn). I used a MIG welder to build up a little bit on the edge of the steel plate of the pad, then carefully ground and filed them to fit snugly in the caliper. After that, the popping noise was gone.

You can check the clearance by pressing the piston back all the way, then try to move the pads back and forth. If they can move at all (it wasn't much in my case... barely noticeable), you may have the same problem I had. I can't give you any hard numbers on the clearance, so I'm afraid it will be a "cut and fit" deal. It's fairly easy to do anyway, but go carefully with the MIG so you don't heat the pad too much. Tack on a little bit at a time and cool it frequently.

If you don't have access to a MIG, maybe changing to another set of pads will take care of it. I still remember how annoying this noise was (not to mention the hours spent on troubleshooting), so I hope this will help you!

I just had the same problem on my 71 SS454 Elcamino and the nuts were loose and only 2 shims left.I,m glad I caught it before who knows what?

You might want to make sure that all your ball joints have adequate amounts of grease on them as well. That can always cause a popping noise.

Ball joints will make that kind of noise. graemlins/beers.gif

I had this problem in my Chevelle on the passenger side and one of the bolts on the top of the upper control arm was loose. In addition to the 2 nuts that are used to add/remove shims, there are bolts in the front and back of the upper control arm, I don't know if you checked them. I can take a digital photo if you want.

Check that your upper control arm bolts are still tight and the shims aren't falling out. This happended to me and gave similar symptoms to yours.

Reid

For over a year I chased a very LOUD popping sound in the right front of my 67 Chevelle after I fully rebuilt the front end and for the life of me couldn't locate it. It always did it when I backed up and then hit the brakes. It was worse when I also turned the wheel. One fine day backing out of the driveway, the lower control arm snapped right at the lower ball joint, collapsed the wheel into the fender well and dropped eveything down on the driveway. Scared me silly because one hour before that I had been romping down the road at 65mph and I could imagine what would happen if it snapped at that speed. Turns out there was a small fracture crack on the leading edge of the control arm near the ball joint. I went to the junkyard and found a replacement one, (examined it carefully!)rebuilt it and all is fine. The old (and wise mechanic) at the alignment shop shop asked me if I was backing up and turning and putting on the brakes when it happened and I was amazed. He said that those conditions put the maximum stress on that area under those conditions and it will usually break then and not moving forward. I took some comfort in that comment, but have been spooky since then, b/c those hair line stress cracks are hard to detect, but obviously the popping or snapping sound was from that partial crack moving the metal. That sound went away when I rebuilt that side.

K-2