Excessive brake pad drag?

[Gunnibronco]

I'm trying to figure out if my front brakes are dragging too much. I have some rear bias issues and I want to make sure it's not a problem with the front brakes before changing to a smaller rear caliper. Someone suggested my front pads might be glazed causing reduced effectiveness/rear bias.

1996 F350 brakes- new calipers (not rebuilt), pads, rotors - All Raybestos
Seems like a "tight spot" when spinning the hubs after installing calipers. Hubs spin fine before calipers are installed. Both sides are the same.

400 miles and the pads look like this. Fairly smooth and slight shinyness. Not as bad as images when you Google "glazed pads", but I'm not sure.

PXL_20231110_034438364.jpg

PXL_20231110_034459540.jpg

Disassembled everything. Resurfaced the rotors with Scotchbrite/Roloc disk on die grinder. Sanded shiny surface off pads (I know that's kind of ghetto). Reassembled, everything is fine but drag is still the same as original install.

Drove the truck and bedded brakes with consecutive hard braking from about 50mph to 10mph. Drove home for 10+ minutes, mostly highway, a few mellow stop signs and pulled into my driveway. I took a quick temp measurement on the rotors. Front= 170*, Rear =80*, ambient temp is about 45*. (Rear brake bias is the same as before dissassembly/reasssembly).

Put the front end on jackstands, spun wheels by hand. I only get about 3/4 rotation at best spinning. Remove wheels and tires, there is drag throughout the rotation with a tight spot at one point. Both sides are the same. Opened caliper bleeders to relieve any possible pressure from MC and drag remained the same.

Is this normal? I feel like there is more drag than I expected.

[Kinder]

Are the calipers getting hung up on the mounting points somewhere? I’ve never greased the contacts points, but might be worth a try. Fairly sure any rotor I’ve used has a high spot, nature of the part.

[Gunnibronco]

Thanks, I managed to find my mystery drag.

Over the last week I've disassembled, greased and reassembled everything several times. I even removed my bolt on wheel spacers, and changed one new brake caliper hanger for an old one from the axle I cannibalized for the knuckles. I even disconnected my MC from the h-booster, opened bleeders and brake lines at multiple spots on the front system.

Every time, both calipers acted the same. There was a "normal" amount of drag until I applied the brakes with the motor & hydroboost running (drag was even fine if I applied the brakes without the h-boost assist). After pumping the brakes with the h-booster assist there was an excessive amount of drag to the point where I could barely turn the rotors by hand. If I installed a wheel and tire, I could turn the tire but it would not continue to spin after I stopped spinning the wheel.

I posted on a FB page for offroading and someone mentioned they had a burr on a brake pad plate that hung up their brakes. I was completely out of ideas and although I didn't see a burr, I decided to file the surface where the brake pad rides on the caliper hanger anyways. Under the coating on the pad backing plate, I saw how the metal was distorted probably when pressed/cut by a dull punch. I filed all the surfaces on the pad backing plate until the distortion was removed and reinstalled them. Now the pads slide more easily in the hanger and they are obviously retracting with the caliper pistons. Before, they were binding up and not returning to position and slightly dragging on the rotors. I'm not sure if the "burr" from manufacturing was a problem, or if the clearances were just too tight between my new caliper hangers and new pads. Before filing, my pads did slide by hand, and weren't obviously stuck or binding when installing them, so I'm very happy someone mentioned this and that I decided to clean them up before I started throwing new parts at the truck. I would never had guessed they were causing a problem.

I had noticed it took a little more gas pedal to get moving from a stop and my gas mileage had dropped since installing my new axles. I wrote both off as part of the new axle swap. But now the truck is easier to get moving, and it rolls more easily on inclines/stop signs/etc. I also tested my caliper temps after a similar drive and the fronts are running 50*-60* cooler.

Now that this is done and I'm confident my front brakes are good, I can concentrate on my rear bias which still remains. I had some hope this would help balance the fronts and rears, but it hasn't. So now I will be swapping the rear JD7 calipers (3" piston) for Eldo calipers (2.5" piston). I'm pretty sure this is going to make my pedal feel firmer with even less travel to get full braking. I have a smaller master cylinder ready to swap in if this is the case. I like a firm pedal, but I'm right at the point of having no ability to "feather" the brakes and think the smaller rear caliper will only exacerbate this to the brakes either being on or off, no in between. Unfortunately, I need to order new hoses from Crown Performance for the Eldo calipers. They are 7/16" banjo bolts, and the JD7 are 3/8 or 10mm. I had my lines made with the banjo fittings built in and can't just swap the fittings at the calipers. So it's going to take a few weeks to get new hoses made and shipped.

[BOBS 2 68S]

Burrs on the pads. Going to file that one away for the next time I do any disk brake work.
Thank for the info.

[Gunnibronco]

Burrs on the pads. Going to file that one away for the next time I do any disk brake work.
Thank for the info.

Yep that was a new one for me too. I never would have thought the pad fit was the problem. Even after disassembling and reassembling and inspecting it all several times there was no sign that was causing the problems.

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[Jesus_man]

Strange one! Mine are too loose and no spring clips, so they bounce once the get a little heat in them.

Glad you got it sorted.

[Gunnibronco]

Strange one! Mine are too loose and no spring clips, so they bounce once the get a little heat in them.

Glad you got it sorted.

Me too, I wasn't even looking at the front end until someone mentioned poor front brake performance contributing to my bias issues. So it wasn't even on my radar. I kind of forgot about how much drag the front seemed to have when I assembled it. I never smelled the front brakes overheating so it probably wasn't a huge issue. I wonder if the pads would have worn in and loosened up over time.

If anything I'll probably realize better MPGs. It didn't seem to change much otherwise.

[Jesus_man]

The basis of all my vehicle mods are "improved MPG"!! Or that is what I tell my better half!

[ZOSO]

now i need to tear apart my bronco. The fronts have always dragged really bad. everything is all new minus the caliper mounts. So i'll check the pads and file away if i need to.

[Gunnibronco]

now i need to tear apart my bronco. The fronts have always dragged really bad. everything is all new minus the caliper mounts. So i'll check the pads and file away if i need to.

Looking at how the EB brakes work, I'd take a look at how the caliper slides on the hanger and the spring. That could cause things to hang up a lot like mine.

I really was at a point where I was going to put it together and run it. I wondered if everything was normal and I was worried about nothing. But it was a world of difference when I clearanced the pads.

I kind of wonder if I've damaged the pads or rotors by overheating them. But I'd think if damage was occurring you would smell something. I've driven about 500 miles including a fair amount of highway miles to & from trails.

The pads had a shiny top layer, nothing terrible like if you Google "glazed brake pads". I've sanded those off with 80g on a flat surface.

The rotors have a different "color" than the rears like they have been warm. I've dressed them with a roloc/scotchbrite on a die grinder, but they still are darker than the rears.

I'm going to put some miles on it before I make any more changes, front or rear.

[Jesus_man]

I'll bet you are good Chad. As you say, if there was a real issue, you would have smelled them best case, or saw smoke bellowing out of the fender.

[Gunnibronco]

I'll bet you are good Chad. As you say, if there was a real issue, you would have smelled them best case, or saw smoke bellowing out of the fender.

I'm thinking you are right. Our trips to and from Blue Lakes and the Super Cel in Carson would have left us smelling something if there was a real problem. We had 3 Bronco noses on site and no one mentioned anything. LOL. I also drove to Loon Lake for the Rubicon, stopping for gas in Strawberry after a long down hill at highway speed and didn't smell anything.

[ZOSO]

It takes a lot of heat. I wouldnt hesitate to run em. Mine are the chevy stuff so they slide on the bolts.