JimiJams

So, I was trying to extract some bolts today (seems no one has luck without a welder) and got sidetracked, which led me to notice that my front brakes drag a lot. I've noticed this in the past but never really gave it much thought. Neither of my front wheels will spin freely, I need to use a bit force just to turn them. The truck wasn't in 4wd either.

Also, in the past when I've changed the pads I remember the pistons being a little difficult to push back in. I've had a spongy brake feel as well for a few years now. Actually it's more of brake pedal travel issue, I'm not sure how spongy they really are. I've flushed the brake system probably 6 times over the years and even replace the MC, but to no avail.

My question is, with this much brake drag should I just replace the calipers? Or do you think the trouble I've been having with the brake pedal feel over the last few years might be related to my dragging brakes?

wyoming9

iTrader: (1)

Do your brakes smell hot every time you get out of the truck??

Ever replaced the rubber brake hoses when they get old they tend to blow up like a balloon ??

Just how much drag are you talking about??

It takes every bit of strength you have to turn the front wheel off the ground??

One side or both the same??

JimiJams

The brakes never smell, and I've never seen smoke or anything like that. The rubber hoses I don't think have ever been replaced. I've checked them before trying to figure out what was causing the bad brake pedal feel, but they were alright. I'll check them today again and have someone push the pedal while I'm checking.

It doesn't take every bit of strength, but takes a little effort and both sides are affected; takes the same amount of force to turn each wheel. It's hard to explain how much strength exactly it takes, but what I can say is the wheels will not spin freely at all. Once I take my hand off they're done moving, just doesn't seem right. I'd imagine it's killing my fuel economy a bit.

When reading of others with similar issues, I saw mention of the MC or broken down brake hoses being the culprit. But I think those people were experiencing intermittent lockup issues, where the brakes would start smoking.

I was assuming my brake drag wasn't normal, and wondering whether I should just replace the calipers or maybe look elsewhere for a root cause first.

DailyDrive

Just how much strength do you think you have in your hands?

I'll give you a hint, your legs have many times more strength than your arms. And you'll barely be able to get up to 25 mph on a bicycle using your legs. And you are moving only your body. Think how much energy it takes to move a 4000lb 4Runner 25mph. Now think how much energy to move it at 70mph.

Your MPG might be affected by 0.01% at most.

Just take an infrared thermometer after driving and measure the temperature. They won't be hot at all. If they were dragging enough to create heat, you would not be able to turn them with weak hand muscles. It's just basic physics.

wyoming9

iTrader: (1)

If they are not burning they most likely are normal .

If you feel you need new calipers by all means go for it.

Most likely won`t be different but you might feel better.

JimiJams

DailyDrive,
That's true, I suppose intuition got the best of me on that one. But, I'd still like to know what could be causing it. The less friction, the better; even if it is just a .01% reduction in efficiency.

wyoming9,
I might just get new slider pins and throw them on and see what happens. The old ones are rusted as hell. Maybe the anti squeal compound is acting like a filler between the pistons and pads and keeping them pressed against the rotor. I just replaced the pads a couple years ago so there's still a lot of pad left. Once it wears down a little, maybe the drag will stop.

wyoming9

iTrader: (1)

Well with your torque wrench measure what it takes to turn the front wheel

Should be around 18 Foot pounds or so

There should always be some friction on the front pads when every thing is working correct

DailyDrive

Not if you think about it from a financial perspective. Spending $100 to save 1 cent is a dubious proposition.

JimiJams

Well, when things aren't working properly I like to find out what's causing it right away, otherwise they have a tendency to get worse. You're talking immediate consequences; yeah, my fuel economy may not be affected much at all right now. But who knows what could happen down the road, if there is actually something amiss here. I was more interested in the cause of the drag in this thread, not the fuel economy or financial details.

DailyDrive

You can pull up the rubber boot around the caliper piston and spray some WD40 in there. If there is sticking, it sounds very minor, this this will probably resolve it.