Front calipers dragging

[thesado]

The front calipers on my 72 are dragging even though they are releasing completely. They rub and squeak when driving down the road.  I assume this is because the return springs are missing (which i have been unable to find to replace) but I've read that a lot of people don't use those anyway.

What should I do? 

[OUTLAW]

disc always drag slightly and squeaks and squeels are caused by the pads vibrating against the rotor ... if you don't have the hardware in there the next best thing is to use a anti-squeal material on the backside of the pads to absorb the vibrations- I use CRC disc brake quiet-goes on like phlegm but sets up between silicone and soft rubber  try that

[Chryco Psycho]

for about $18 each you can buy rebuilt calipers , there is no return spring

[thesado]

what about these: http://cgi.ebay.com/ebaymotors/69-70-74-Cuda-Road-Runner-300-Mopar-Caliper-Charger-R-T_W0QQcmdZViewItemQQhashZitem22fe8378b0QQitemZ150298917040QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories#ht_500wt_1182 ?  And I've already rebuilt the calipers.

[Bullitt-]

Just read that if the push-rod in the master cylinder is too long it will cause brakes to be on all the time.... Otherwise have you greased your brakes?....not kidding, there is need to lubricant, with proper product, the moving parts, not the friction surface.
http://www.amazon.com/CRC-SL3301-Synthetic-Caliper-Grease/dp/B000M8Q234 

[Chryco Psycho]

the anitrattle springs could help , semi loaded calipers come with the springs , not sure where to get them separatly

[72cudamaan]

The lube you need is antiseize on the caliper slides. And when you rebuilt the calipers did you replace the seals. They are actually not sqare cut seals but tapered. The seal when working properly helps pull the piston back into the bore ever so slightly to reduce the drag. The drag should be there, but minimally so that you dont have "slop" in your brake pedal.

[Aussie Challenger]

They are actually not sqare cut seals but tapered. The seal when working properly helps pull the piston back into the bore ever so slightly to reduce the drag. The drag should be there, but minimally so that you dont have "slop" in your brake pedal.

The seals are square, the groove they sit in is machined with a taper to twist the seal slightly to help return the piston as mentioned, that way installing the seal incorrectly cannot happen.   
When you cleaned everything was the piston surface smooth or marked/pitted or scratched, if the bore is damaged or marked the piston will stick also. Did you check the fit of the pistons in the bore before installing the seal?   

[thesado]

I should have been more descriptive... The caliper seems to be working well since the rebuild.  The problem seems to be that when the caliper retracts it seems to still rub on one side.  Since the caliper floats around the disc and the disc isn't perfectly plane it will squeak squeak squeak going down the road.  When I jack up the car and roll the wheel I can hear the pads.  If I remove the wheel and hold the caliper I can get it to stop rubbing simply by holding it.  When I got the car and worked on the brakes it had one "positioner" spring on each caliper. But I'm not sure if they were correct because they didn't seem to really fit well.  I knew that one spring per side was incorrect anyway, so i left them off and have not been able to find replacements.  I assume they would be necessary, but everyone I've talked to says to leave them off.

[Bullitt-]

I don't see that the Positioner clips do anything...once you tighten down the Pin it does not move.

       
Anti Rattle Spring may help..... Some pads I got for another vehicle had shims that clip on the pads to keep them tight against the addapter..had never seen those before but I put them on along with GREASING all the metal-to-metal surfaces & they are very quiet.

Something like these


        There was a post once discussing adding spring coils on the pins between
        the pads....I'll see if I can find.

[thesado]

I don't see that the Positioner clips do anything...once you tighten down the Pin it does not move.

The pin doesn't move, true. But the caliper slides along the pin freely.  I can't see them installing it if it really isn't necessary.
 

[SBDave]

You said the "discs aren't perfectly plane" ... are they warped? or just warn?  If they are warped then just having them machined might cure it.  It cost me $40 to have both rotors turned.  If they are warn down I'm not sure if machining would cure your problem, but it can't hurt.

While rebuilding my front suspension I did my brakes.  Had the rotors machined by a local shop and I fly cut my brake pads and rebuilt one of my calipers (replacing the piston seal and dust boot). 

Good luck!
-Dave

[thesado]

They're worn.  Can't turn em down anymore.

[73EStroker]

It will only cost you money to fix it - IMHO you should buy new calipers (as CP suggested) and new rotors. If you are going to buy new rotors and want better braking power then buy the Cordoba ones and obtain a set of 12" rotor caliper mounts. You will not believe the difference in stopping power. I also use the hydraboost - stopping is not an issue for me other than locking the wheels in a sudden stop.

[purple1]

They're worn.  Can't turn em down anymore.

I think that may be the problem. The rotors need to be true, or they will make lots of noise.
The pin positioners seem to only keep the inner bushings from moving out of the calipers. That could make for real trouble if the bushings pop out though.
The anti-rattle springs are what most people leave off. They don't seem to do much of anything.

Dave