Hello I have a 68rr coupe 383 4 speed survivor car with Power Brakes and hemi grind cam. The car sat in my garage for 7 years while I was raising my 2 young children. Last year I decided to get it up and running. I did notice the brake reservoir had very little fluid and upon removing it, noticed the brake fluid in the brake booster had become a somewhat harden gel. I removed it all, replaced the reservoir and bled all brakes real well. This year noticed a brake drag. While I am coasting to a stop, notice after taking my foot off the brake, the brakes are still applied, then will disengage . Kinda hard to predict how long the drag will last. However I am able to push the car without any drag . My research shows many symptoms such as readjusting the PB adjustment pin, spraying silicone spray on the pin itself. It has only 58000 miles and only starting this drag AFTER I replaced the reservoir. Any thoughts where to start? Hope everyone is safe with covid 19.
Brake Drag
- Thread starter paulv
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Zizzinator
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Sounds like the return on the booster is getting stuck. Had the same issue in my superbee. brakes locked hard one day and wouldn't let go until I pulled up on the brake pedal opening the release valve in the booster. Yours is clearly not THAT bad, but sounds very similar.
On an empty road, drive around a bit then come to a stop and see if the brakes drag when you start moving again. Then repeat but tie a string to the pedal (to pull up with) or use your foot when you let up on the clutch to pull up on the pedal and see if it releases the drag.
Check to see if your pedal is coming back up to the full stop position or if it's sitting half an inch lower than the clutch pedal when released. This will also let you know if the return on the booster is working.
Only other thing I can think of is there is gunk in the caliper/drum pistons (not sure what you're running) and it's preventing their release. This is not really likely as most gunk would be diluted or flushed when you bled the brakes. worth a check though. only way to do it though is rip em apart and flush them with brake cleaner, re-bleed the system, and test again.
Could put it up on jack stands after driving a bit and see if after pushing the pedal down which of the wheels are dragging. if it's the rears you're more likely to have a bias balance problem, check for kinked lines or adjust the bias valve (if you have one). if it's the fronts dragging more then you've got a pressure problem and the booster isn't releasing fully. If it's just one wheel then there is likely gunk in the piston.
On an empty road, drive around a bit then come to a stop and see if the brakes drag when you start moving again. Then repeat but tie a string to the pedal (to pull up with) or use your foot when you let up on the clutch to pull up on the pedal and see if it releases the drag.
Check to see if your pedal is coming back up to the full stop position or if it's sitting half an inch lower than the clutch pedal when released. This will also let you know if the return on the booster is working.
Only other thing I can think of is there is gunk in the caliper/drum pistons (not sure what you're running) and it's preventing their release. This is not really likely as most gunk would be diluted or flushed when you bled the brakes. worth a check though. only way to do it though is rip em apart and flush them with brake cleaner, re-bleed the system, and test again.
Could put it up on jack stands after driving a bit and see if after pushing the pedal down which of the wheels are dragging. if it's the rears you're more likely to have a bias balance problem, check for kinked lines or adjust the bias valve (if you have one). if it's the fronts dragging more then you've got a pressure problem and the booster isn't releasing fully. If it's just one wheel then there is likely gunk in the piston.
This is perfect. I will follow these instructions. I do know however, the brakes will release as I am slowing down to about 5-10mph. I then will go from a dead stop and brakes are free. They only drag for about 5 seconds and at low speeds. But I will get the car up to 45mph and hit the brake and see if speed matters, weekend project coming up. Thanks immensely
69hemibeep
Sponge Bob Square Wheels
You could also have a bad rubber hose, put it in the air and see if it is one brake.