1972 Dragging Left Rear Brake
Hello all, I am a long time member, but this is my first post here. I recently moved to Texas from NJ and trailered my 1972 Coupe, 350 base motor, 4 speed, to my new home. My issue first popped up after I had a new set of steel rally wheels installed that I received for Christmas. Wheels didn't fit and Mid America found that the wheels they were selling had the incorrect backspacing for my Corvette. I contacted Corvette Paramedics in NJ, where I had my car serviced while I lived there, and they were able to get me a new set of wheels. I had them installed by a local tire shop recommended by my neighbor that owns several 70's muscle cars. I was out for my first drive with car with my t-tops off and noticed a burning brake smell, but thought it was from another vehicle. The smell didn't go away and when I got home and pulled into the garage it was obvious the smell was definitely from my car. While I walked around inspecting the car I noticed smoke coming from the right rear brake. The area around the wheel was hot. The left side was fairly cool. I spoke with my neighbor, who also owns a Corvette, and he asked if I set the parking brake in the garage. I told him I did and he suggested that I didn't, as they frequently stick. Another neighbor, a mechanic, said he would take a look at it for me. We jacked the car up and turned the wheels by hand and they both moved fairly freely. He thought maybe the parking brake had been stuck because the car had sat for a couple of weeks while I waited for the new wheels, was now operating properly and that I should take the car for a test drive. On the test drive the brake smell appeared towards the end of my route. I would estimate that I drove approximately 7 to 10 miles. We put the car back up on a jack and we were unable to turn the right rear wheel. We took the wheel off and discovered that the caliper appeared to be locked. I obtained two rear calipers from a Corvette restoration shop near me and we installed the new calipers with no issues. I was unable to do a test drive until this afternoon. I had my a/c on and the windows closed for part of my test drive. About half way through I turned off the a/c and a short while later I noticed a faint brake smell. When I got home the right side was very hot and the left side cool. I jacked up the car and was able to turn both wheels with what seemed to be about the same amount of resistance. I baffled as to what could cause the one brake to stick. Any suggestions?
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Re: 1972 Dragging Left Rear Brake
James
When you replaced rear calipers, did you also replace flexible brake lines?
Have you adjusted (backed-off) parking brake shoes?
DaveJudging Chairman Mid-Way USA (Kansas) Chapter -
Re: 1972 Dragging Left Rear Brake
No we did not. Is it possible for one of these lines to collapse and not release the caliper?Comment
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Re: 1972 Dragging Left Rear Brake
Thanks Dave. The recommendation would be to change the rubber lines then?Comment
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Re: 1972 Dragging Left Rear Brake
James------
The rubber lines should be replaced when calipers are replaced. If the lines are old/original to the car, they should definitely be replaced.
Post a photo of the crimped ends and I can tell you if they are likely original to the car.In Appreciation of John HinckleyComment
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Re: 1972 Dragging Left Rear Brake
Yup - the rubber line is the first suspect; they'll "hour glass" internally and then act as a one way valve holding pressure on the brake line, next is the parking brakes; I have a running thread about my 63 right rear brake dragging on here right now - both rear parking brake cables were frozen up. Waiting on cable mounting hardware to determine that new cables fixed things. If you drove to the point your brakes smoked you may have warped a rotor and/or glazed the pads.
Best to change rubber lines on both sides of rear when you do it.Comment
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Re: 1972 Dragging Left Rear Brake
Thank you for the information! Would you be able to feel if the rotor was warped when driving? I felt nothing while driving. No pull, no anything. When I had a leaky front caliper that was very obvious, as the car would "dart" to the side of the good caliper. As a side note, I know rubber brake lines collapsing could happen on a dirt bike I owned many years ago. I was wondering if it was possible on an auto too?Comment
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Re: 1972 Dragging Left Rear Brake
Thank you Joe! Here are the two ends of the rubber brake lines.IMG_2284.JPGIMG_2283.JPGComment
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Re: 1972 Dragging Left Rear Brake
If you're asking me - the 63 has factory drums and yes; the RR drum got warped to the point stops above 50 mph were a rumbling freight train ride - bought new drums. And, yes, rubber brake lines can appear fine externally but deteriorated internally and develop a severe restriction (not necessarily a "collapse") and its a VERY common occurrence. Of course the issue is much more noticeable if it occurs on the front axle as the front brakes do most of the work.Comment
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Re: 1972 Dragging Left Rear Brake
Thank you Frank. Replacing the rubber brake lines will be the next step and hopefully that solves the problem.Comment
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Re: 1972 Dragging Left Rear Brake
James------
The first picture shows a single crimped brake line of the original configuration. This means it's either original to the car or a very early GM SERVICE hose. There's no way I would have a hose like this on a driven car whether it's the source of your problem, or not.
The second picture is of the emergency brake cable and is not relevant. However, it does not matter; the first pix shows me all I need to see.In Appreciation of John HinckleyComment
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