Hi All,

Last summer, I did a front end job on my '81 Bronco.

New pads, calipers, disks, wheel bearings / races, booster, and master cylinder.

However, lately I discovered that my front brakes are dragging.
When I jack it up and spin the tire, there isn't any free rotation. They take some effort to get moving and then just stop instantly after I let go. I took the tire off, I could barely turn the rotors by hand. But, once I remove the brake caliper, they spin nice and free. This is the same on both sides.

There doesn't appear to be any uneven wear on the pads and the piston in the calipers seem to move well. Also, just to check, I unbolted the master cylinder from the booster to see if somehow it was constantly putting a little pressure on it, and there was no difference.

Any ideas? I'm not particularly sure what to do about this, and it's taking a hit on my performance, not to mention my gas mileage. Don't know what to look into next.

Thanks.

 

Sounds like the pistons are sticking in the calipers. Both sides do it? Coincidence or bad rebuilt calipers. Most of the rebuilt stuff now is crap from china or somewhere else that no speakee engleesh.

 

It could possibly be the brake hoses are bad. From the outside they look fine, but as they weather and wear the inside liner of the hose will swell. In time it will actually restrict the back flow of brake fluid. When you take your foot off the brake pedal there is still some pressure trapped in the caliper(s) causing them to hang up or drag. Just my two cents, hope it helps!

 

Pkupman82 and Others: This is intriguing to me. I have black brake dust on the front wheels from wearing brake pads, and I am going through brake pads too soon. Is there a way to test your theory on my rig? If they are in fact bad, what do you recommend to replace the brake lines with? Motorcraft or something else?

 

That's what I'm thinking it is and am going to look into that this weekend. Hopefully that's all it is.

 

AbandonedBronco: Would you mind posting what you find (maybe even with pictures if possible). I don't want to open up my brake system by disconnecting brake lines if an internal restriction is unlikely.

 

For sure.

 

As far as hoses go I have had good luck with Napa and Advance Auto brand brake parts. Speaking of brake pads, I have taken a liking to Power Stop ceramic pads. I have installed them on all our vehicles, they run quiet and don't dust the wheels badly. Napa carries them I know for sure.

 

Okay, turns out the calipers simply weren't returning to center. If I took a large screwdriver and simply got some leverage and shifted the calipers to the left or right, the wheels spun much more freely.
I took them off, and the surfaces where the calipers make contact with the body were bone dry. I polished all the surfaces up until they were shiny, and then applied a generous amount of brake/caliper grease and then reassembled.

It seems to have helped quite a bit but still drags a little (but not nearly like it was). I'm thinking the rotors are slightly warped from being hot from always dragging. Not sure when I'll get around to it (it's a bit more of an involved job), but I'll pull them off and have them turned. Hopefully that'll make it all like it should.

 

Warped rotors is sort of a catch all phrase that doesn't really mean much. It does happen for sure, but not very often. Hard or glazed spots on the rotors is very common and contributes to the pulsing in the pedal often associated with "warped" rotors. Turning won't help this, at least not for long. It comes right back. Might be better to replace them. With all that, 30+ year old brake hose is due for replacement.