Draggin sound(?)

[pasvorto1]

I am still experiencing (albeit randomly) a 'dragging' sound from the rear of the car. I thought it was a sticking caliper. I changed both calipers. The sound seem to go away. Then, yesterday, while out on a 100 mile ride (to burn off the winter gas) it started again. I was about 70 miles into it and came to a stop sign. As soon as I went to leave, back came the "sticking sound". I can't believe it's the (new) calipers sticking again. The emergency brake hasn't worked since I've owned the car. Another project on the list. Is it possible that the EM could be grabbing? If so, is there some quick way to disconnect it until I can get it into the shop?

 

[jdp6000]

It sound like it could be the emergency brake minature shoes inside the rear rotors. Does the sound go away when you apply the brake?

Jim

 

[pasvorto1]

I can't remember if that happens. However, it does go away as I start driving off.

 

[jdp6000]

Find a time when it does happen. This time drive away with slight pressure on the brake pedal. If it goes away its possible the rear calipers again...or maybe a build up of winter rust on the rotor. If it doesn't go away its something else. Most likely the brake shoes inside the rear rotors. I should also mention that I'm not 100% sure your car has that type of emergency brake system...but I did have a 77 once and thats the system it had.

 

[pasvorto1]

Wouldn't you know that all spring I have been driving it and not a peep. The first time my wife decides to go along for a ride...

 

[jdp6000]

Never fails ay???? Maybe she tried the emergency brake when you weren't looking???

Sounds minor anyway. My money is on the emergency brake shoes....

Jim

 

[pasvorto1]

I wish I knew of a good Vette mechanic within shouting distance of SE Minnesota. Looks like I might have to take it up to the Chevy dealer and hope the vo-tech mechanic can read the assembly manual. Sorry, that was mean. The local dealership did spend the last year doing a frame-off resto of a 66 for someboday. I saw it the last time I was there. I was looking for lugnuts. They didn't have any that woudl fit. Not a good sign.

 

[Jack]

? collapsed (internally) rubber brake hose

I am still experiencing (albeit randomly) a 'dragging' sound from the rear of the car. I thought it was a sticking caliper. I changed both calipers. The sound seem to go away. Then, yesterday, while out on a 100 mile ride (to burn off the winter gas) it started again. I was about 70 miles into it and came to a stop sign. As soon as I went to leave, back came the "sticking sound". I can't believe it's the (new) calipers sticking again. The emergency brake hasn't worked since I've owned the car. Another project on the list. Is it possible that the EM could be grabbing? If so, is there some quick way to disconnect it until I can get it into the shop?

It could be the flexible rubber brake hose(s). An aging hose can collapse INTERNALLY ... and you won't see it from outside. The pedal pressure can be enough to push fluid through hose to caliper ... but caliper cannot push back with sufficient pressure to quickly overcome the collapse ... it'll usually overcome it after a very short time. Mine acted like you describe and it was a rear rubber brake line at fault ... I changed all 4 corners. If your hoses are old ... try replacing them ... they're fairly cheap and available through local parts house ... but they can be a bear to break loose from the car's steel hardlines. So, (if you do the repairs) make sure line wrenches are used and preparations made to replace steel hardlines (if they get damaged during hose R&R).
JACK:gap

 

[pasvorto1]

That's an interesting thought. I replaced the steel lines when I replaced the calipers. I didn't replace the rubber lines, though. Hmmm....

 

[Vettehead Mikey]

Dragging brakes usually don't make any sound- otherwise they would do it everytime the brakes were applied by the driver.

To help isolate the source, next time you're out driving and heard the noise, stop and lightly touch the wheels and centre hubs. If there's one dragging you'll feel the difference in heat output.

 

[pasvorto1]

It's like it grabs and then releases and then grabs. I envision a wet brake pad sticking to the rotor.

 

[JohnZ]

Do you feel the sensation when leaving from a stop going straight ahead, or only when turning a tight corner?

 

[pasvorto1]

Actually, I can feel it start "grabbing" when I start stopping. I know, then, that I will get the sensation when I leave. Straight or not has not bearing on it.

 

[Vettehead Mikey]

If it's a pulsating feeling coming through the pedal, you may have excessive lateral runout on the rotor.

 

[Jack]

That's an interesting thought. I replaced the steel lines when I replaced the calipers. I didn't replace the rubber lines, though. Hmmm....

Seems you recently replaced both hardlines and calipers... if so, it shouldn't be too difficult to break the rubber hoses loose from hardlines and calipers. The most aggravation would likely be the RE-bleed.

Wagner/Federal-Mogul brake hose P/N's:
FRONT: BH86433
REAR: BH66724

Raybestos/Raymold is another good brand. Depending on brand & buyer's category ... Roughly $10-$25/hose & locally available.
JACK:gap

 

[pasvorto1]

There is no "pulsation" per se. Not like a warped rotor or ABS. It's more of a 'sound' of something binding. Once I get rolling it goes away, just like a sticky caliper finally breaking loose. Maybe I need to change the front calipers. The noise sounds like it comes from the back, but that can be deceiving. That's why I was thinking about the Emergency Brake maybe acting up.

 

[Jack]

There is no "pulsation" per se. Not like a warped rotor or ABS. It's more of a 'sound' of something binding. Once I get rolling it goes away, just like a sticky caliper finally breaking loose. Maybe I need to change the front calipers. The noise sounds like it comes from the back, but that can be deceiving. That's why I was thinking about the Emergency Brake maybe acting up.

Very same symptoms as mine had ... not blowing smoke up yer butts folks ... do as you please ... mine had simply a collapsed hose.
JACK:gap

 

[pasvorto1]

That sounds like an easy enought fix. I will do that first and report back.