Caliper drag

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chillent

chillent

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So I'm getting ready to put my new M/T aluminum wheels on the front of my Barracuda and I noticed the front calipers are dragging fairly heavily on the disk ... anyone got any ideas?

It's a '68 with the '74 and up swap to disks. Using a Diplomat aluminum master cyl and stock prop valve. I followed the Disc-o-tech article almost to the letter. Car breaks fine and has never given me issues but the drag can't be good for the disk or my ET's!

Any suggestions appreciated.
 
how long since the brakes were rebuilt?
the pistons should only move in about 4 thou and the caliper o ring should go back to its original shape and retract them.Maybe the caliper race is worn and needs to be filed flat or add a bit of silicon lube?
 
ir3333 said:
how long since the brakes were rebuilt?
the pistons should only move in about 4 thou and the caliper o ring should go back to its original shape and retract them.Maybe the caliper race is worn and needs to be filed flat or add a bit of silicon lube?
Click to expand...

Well, probably about 10 years old since installed and they were new (remanufactured) when installed. I will look at them closer.

jimjimjimmy said:
it could also be a bad brake hose .
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can you explain further? not quite sure how the hose could do this?
 
when a brake hose goes the inside lyre of the hose delaminates and shuts the back flow of brake fluid off and holds pressure on the caliper if that makes sense if not someone will explain it better.
 
jimjimjimmy said:
when a brake hose goes the inside lyre of the hose delaminates and shuts the back flow of brake fluid off and holds pressure on the caliper if that makes sense if not someone will explain it better.
Click to expand...

that actually is understandable! I'm actually wanting to upgrade the stock rubber hoses anyway to braided ... does anyone make a direct fit replacement? I see Jegs has pre-made ones maybe one of those will work.
 
jimjimjimmy said:
when a brake hose goes the inside lyre of the hose delaminates and shuts the back flow of brake fluid off and holds pressure on the caliper if that makes sense if not someone will explain it better.
Click to expand...

That's about all there is to it. The inner lining of the hose can collapse and restrict flow back to the master cylinder, which can hold the brakes on. Especially true if the hoses have been clamped with vise grips for the caliper swap process. I've seen brand new hoses ruined like that, it's a lousy habit to get into. Plug the hole or catch the brake fluid. From the outside the hoses can look ok too, the brakes dragging or locking up is usually the only symptom.

The other thing is that it really takes the disk spinning at speed to knock the pads back. If you step on the brakes and just turn the wheels by hand with it up on stands I would expect them to drag a lot longer before the pads get knocked back, with the car rolling it only takes a second. The wheel bearing end play can make a difference there too. But there were old school drag racers back in the day that would switch disk cars to drums because of the pad drag. Can't imagine there's much to be gained there though.
 
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