Hello, sorry if this thread is not in the right forum, anyways I was looking to get some help with my front brakes dragging. I am driving a 2010 Mazda B4000, 4.0L, 4x4, with 145 000km on it. Both of my front brakes dragging causing lots of brake dust to accumulate on both wheels. When I'm driving I I do not feel really any pull from my brakes at all, it just when I'm driving at lower speeds around 15-60 km/h I can hear my brakes squeal. Also, when braking my pedal feels fairly firm and very spongy. When I am braking I do not feel like I have any issues coming to a stop, other than my brakes squealing. When my brakes are squealing while I am driving I tap the brakes and the noise goes away temporally. Back in November, this issue was happening with my brakes so I got both of my front calipers replaced since the guide pins were seized on them. Shortly after replacing the calipers, my brakes were continuing to drag and squeal. I was wondering if it could be from bad brake pads, clogged brake lines, a master cylinder, or possibly something else? I was wondering the ways I could possibly diagnose what is the faulty part or issue that is causing them to drag.

Thanks!

 

Welcome to the forum

Could be a couple of things

Power booster's atmosphere valve could be leaking
Inside the cab at the end of the brake pedal push rod, inside the booster, is the atmosphere valve
Power brakes work by putting a vacuum(negative pressure) in 1/2 the booster, when you press down on the brake pedal it pushes open the atmosphere valve, atmosphere pressure is 14.7psi at sea level, that pressure, along with the negative pressure, "assists" you in pressing down the brake pedal
If atmosphere valve is leaking its the same as you lightly pressing the brake pedal all the time

Easy way to test for this is to first drain the negative pressure from the booster, easy to do, engine OFF, press down brake pedal 3 or 4 times, should be easy to press 3 times then it should get hard to press........... reserve negative pressure is used up
If its hard to press after 1 press or right off the bat then booster is leaking

After booster is drained, open hood and take cap of master cylinder, then open up a bleeder on either front caliper, should have a slow flow/drip of brake fluid, that's gravity flow, there should be NO PRESSURE in a brake system if no one is pushing down the pedal
Shut bleeder
Start engine
Open bleeder again, should be the same slow flow, if you get a squirt then replace booster

Yes, the flexible brake lines at both front wheels can fail inside and act like a valve and hold pressure in the caliper so pads rub
BUT............both of these failing at the same time is an extreme long shot

Master could be holding pressure, after use, so hard to tell if its the booster or master if you get a squirt from caliper after pumping brake pedal with engine running
You can pump the brake engine off, and then open bleeder, if you get a squirt then it may just be the Master

Spongy brakes usually mean the calipers are really hot, or back brakes are not adjusted
Hold out the Parking brake release, and pump the parking brake pedal until it firms up, this adjusts the rear brakes, you can't over tighten them

If you have 4 wheel ABS it could also be an 4WABS issue

Squealing new brake pads can mean the pads you used were different material than the last pads, so the rotors will need to be "clean" of the old material which can take a month or two of driving
There are:
Semi-metalic
Ceramic
Organic

Each has its own benefits and drawbacks but when you mix them on a rotor it will make noise for awhile

 

Hello, thanks for the quick reply! I finally was able to run some of the tests today. I started off by doing the brake pedal press test and after 2 presses of the pedal it was very firm to press down and it didn't change much with more presses of the pedal. I also watched a video that talked about while pressing down the brake pedal while starting the engine, if it moves down a lot it could be a sign of a bad power booster. While doing this test my brake pedal moved down quite a lot. After draining the power booster with the engine off I opened up the bleeder valve which came out as a steady dribble. Performing this test while the engine was running also had the same steady dribble until I pressed on the brakes and it squirted. I don't believe it could be the 4 wheel ABS system since it hasn't given me any noticeable issues, but I am not too sure how to diagnose if it is the culprit. I have had these brake pads and rotors for the last almost 50 000km so they could be a problem even though they don't look too worn. I think with some of these tests that I might be the brake booster that I need to replace. If you have any more advice that would be great to hear! Thanks again!