Front Brakes Dragging

Hello All,

Immediately after the frame and every existing brake line was replaced, the two front calipers stopped retracting all the way. Most of the way, but not all the way. The drag is noticeable. I pulled both front wheels off and using two hands can barely rotate the front hub a few inches. The rotors are just a few months old as are the pads and both calipers were good. There was no known drag prior to frame replacement. Before I return the truck to the same dealer who did the frame replacement does anyone have any ideas what could cause this? This list is an incredible community of shared knowledge and I truly do appreciate every response. Thank you.

 

One of your new brake lines might have gotten pinched during the install. When you depress the brake pedal, the positive pressure generated is enough to overcome the constriction so the brakes stop the vehicle, but when the pedal is released, there is trapped pressure not letting the caliper return all the way like it normally should.

 

Thanks Timmah!,

I have the truck up on jackstands now and have started checking all the rubber brake lines to the front wheels and from the master cylinder to some kind of junction box on the passenger side fender well. Brake lines exiting that same box go to both front wheels. Could that be a brake line pressure modulator? The truck does drive very well and the brakes do work but that drag is noticeable. Any chance it might be the master cylinder modulator? And do you know what that electrical plug is for that attaches to the side of the master cylinder?

 

I think that box on the passenger side is the ABS modulator no? what year is your truck?

 

Don't just check the rubber lines. A metal line could have be bent or flatened also.

 

I know a little about the brake system in these rigs but not a lot. I just remember a long time mechanic telling me a bad or crimped line could cause the symptoms you're experiencing.

Are your calipers very rusty? Maybe they just got a little corroded over time and you just never noticed it. I'm thinking that maybe the caliper pistons are hanging up a bit due to corrosion and that's why they aren't retracting like they should. Also, did you grease the brake pad pins with caliper grease when the new pads and rotors were installed?

If none of my ideas work, hopefully somebody with more knowledge than me can point you in the right direction to figure out the cause of the problem.

 

Might just be coincidence and you have a caliper that has seized and stuck. It would be tough for a line to hold that much pressure, disc brakes are designed to hold pressure in the lines to keep the pads against the rotor but I would think the line would need to be totally kinked to hold enough pressure to make it hard to turn

 

He says both sides though. I'd check the lines. The elec. connec. is for the light to tell you that fluid is low.

 

Ahh missed that, both calipers freezing at the same time would be odd

 

What about the rears? Maybe its a master cylinder or pedal issue not releasing all the way

 

Thank you everyone! I truly do appreciate your thoughts and suggestions.

The truck is a 2004 Tacoma, access cab, 4 WD, V6 engine, 131,000 miles. The rear drums are free. Rear brake shoes are like new and the drums are smooth with no wear. No issues there. I carefully checked all the front brake lines for kinks, dents or crimps and have not found anything. Every single line and nut is new except for the short rubber brake lines attacked to the calipers. The calipers are several years old but have not been an issue until now. The rotors and pads are only 3-4 months old. The caliper pins were not greased when reinserted. Today I will remove the calipers, clean and grease those pins. The calipers are not frozen in position and are free to move side to side. It's like there is light pressure preventing them from fully retracting. They do not pull to one side or the other during normal driving. I am going to try and open the bleeder screws to see if the fluid is under pressure and if that frees them up. I will post whatever it is I find, or don't find. I am also going to check for the clearance on the rod that goes from the pedal to the master cylinder.

 

Different vehicle but my Master cylinder and booster were causing the front brakes to hold. I changed them both and everything worked fine.

 

yes the booster and/or check valve can act strange sometimes. You would think all it can do is make brakes 'hard' as in 'not power brakes'.