Never ending brake issue

[4x4blaze]

Hey guys, I was wondering if anyone could help me find a solution to my trucks brake issues that I have been fighting ever since I bought it 3 years ago. (I have started a thread about this about a year or two ago, but never really got the answers I needed) It feels as if both front breaks are sticking which is causing the front hubs to get far too hot (Or at least I think) on relatively short city drives. I went on a late night drive tonight which was roughly 8 miles, hit probably 5 or so stop lights along the way, and when I got out and felt the hubs, they were hot. I was able to hold my hand on them for 3 seconds or so before feeling uncomfortable. I have had them hot enough that you couldn't even think about leaving your hand on them though. AND If I jack the front end up and try spinning the front tire as hard as I can with my shoe, it will typically only spin 3/4 of the ways around. Is this normal or should it spin multiple revolutions freely? I feel as if it has way too much resistance on it, but I am clueless on what this could be.

I have replaced virtually everything in the front end and brake system besides the hard lines. New calipers, rubber hoses, wheel bearings ( No, they are not too tight), rotor and hub, master cylinder, proportioning valve, and had even found out recently that the back brakes were never actually working. this truck had sat for quite a while before I bought it, so I'm figuring this had caused them to both seize up. So now it has two brand new wheel cylinders in the rear and therefore the rear brakes are working for the first time ever. But the front hubs still feel too hot after all of this.

I am getting extremely tired of spending money on parts that aren't fixing this problem. My next move would be to get new calipers since I have lifetime warranties on them, but i just don't see how both would be bad at the same time. I'm running out of ideas and patience. Maybe this is normal, but I don't see how it could be.

Any input would be appreciated!

Thanks!

 

[dyeager535]

Were you able to put your front brakes together without incident? I had some brake pads and the (stupid) multi-piece anti-squeak pads(?) made out of metal were too thick, and the pads were constantly in contact with the rotor. The tire would not spin freely at all. You could turn it by hand, but the pads were dragging. Removed one of the pieces of anti-squeak on each side, and that seemed to work. But I had to work hard to make them fit "wrong" the first time, and smack the caliper over the rotor.

3 revolutions sounds about right, but that is going to be arbitrary, and could be influenced by how tight the wheel bearings are.

I've had the fronts so hot it ruined the bearing grease, the grease was smoking and you couldn't touch the hub, but that was a ton of constant downhill, trailer, and inability to compression brake.

 

[diesel4me]

Check and see if there is any free play at the brake pedal before driving the truck,then after its been driven far enough to get the hubs to the temps you noted,see if it has changed..

A slight amount of free play is a must,about 1/8" or so all the time,otherwise the master cylinder piston will be applying some pressure to the brakes,(the fronts kick in first too)--I have seen vehicles have the brakes drag enough this way to eventually lock up the wheels,as the expanding brake fluid ends up applying more pressure..

Some trucks had an adjustable push rod on the power booster so you can adjust this,others do not,some also had a plastic spacer or a gasket between the master and booster--if this gets left off it'll move the master closer to the booster and reduce or eliminate the needed free play...

My front hubs feel too hot to touch after a few highway miles in summer,but I can put a hand on one without much discomfort if I go 5 or so miles under 50 mph,and didn't have to apply the brakes much or hard...usually too hot is defined by boiling wheel bearing grease or "burnt brake pad" smells...

 

[4x4blaze]

Thanks for replying guys! I was just about to soak this truck in kerosene and watch it burn with how frustrating this issue has been!

Anyways, yesterday I jacked the truck up in the front and tried to spin the wheel like I was talking about earlier. Still only spinning 3/4 of a revolution on the right, but about 3 on the left. And after driving it in some traffic, it started to push grease out of the hub again from getting so hot.So I came home and listened to both of your guys inputs!

I also pulled the right caliper off the rotor and put the tire back on to see how many revolutions it would spin just for kicks. With one hard kick, I could get the tire to spin roughly 6 times. after using a C clamp to open the caliper and sticking it back on, it would still spin about 6 times. but then after pushing on the brakes once, it was back to spinning only 3/4 of a revolution. So obviously the culprit is the stupid caliper not releasing that probably has only 4000 miles or so on it.

Were you able to put your front brakes together without incident?

Yes, after using a C clamp to push the piston back in, the caliper literally fell onto the rotor. Not tight at all. So therefore that eliminates that as being an issue. It appears that the caliper for whatever reason just will not release. But thankfully I purchased the lifetime warranty when I bought the last set of calipers literally 2 years ago.So I went up to the good ol parts store and got another new caliper swapped for free. Haven't got around to putting it on yet though.

A slight amount of free play is a must,about 1/8" or so all the time,otherwise the master cylinder piston will be applying some pressure to the brakes,(the fronts kick in first too)

After reading your comment, I went out to the truck and almost unbolted the master cylinder from the booster completely. Therefore, I knew there wouldn't be any pressure at all pushing in on the master cylinder. Spun the tire, an still only spinning 3/4's of a turn. I was hoping you were right because that seems like it would be a relatively easy fix! And I also looked at the rod on my booster, and it doesn't look like it is adjustable either. But as you have read as stated above, it appears the caliper is just sticking(even though they don't even have 5k on them). if I open it with a C clamp, it spins nice and free. But as soon as I hit the brakes once, it goes back to sticking

And, do the front brakes kick in first? I was always under the assumption that the rear brakes were fed 30 psi first, and then after that, opened the proportioning valve allowing the front brakes to get fluid? I'm by no means a wizard with brakes though........... Obviously.....

 

[JoshHefnerX]

What front axle is this? Have you made sure the caliper is able to slide on the pins or the mount?

 

[diesel4me]

I've had more rubber hoses fail internally and act as check valves,than stuck calipers,but with today's high quality rebuilt and new parts,it is entirely possible the caliper is the culprit...that could apply to new hoses too--easy way to see if the hose is making the brakes drag is to pump the pedal several times,then spin the wheel and feel how much drag there is--then open the bleeder screw--if its the hose,the wheel will spin freely...if not,its the caliper sticking or not releasing..

Far as I know the front brakes get pressure slightly before the rears,but I could be wrong...I have read drum brakes need a master cylinder with a check valve for the rear drums so there wont be excessive pedal travel to pump the fluid back there on the first pump,they want it to be "instant"...but the proportioning valve may be set so the rear brakes application is delayed slightly,and with less pressure than the front discs..
In my experience most panic stops I have made lock the front brakes up first,unless I have an empty bed,then the rears may skid first..

 

[4x4blaze]

What front axle is this? Have you made sure the caliper is able to slide on the pins or the mount?

Yes, the caliper was/is literally brand new. Everything in that aspect was working fine. Just for whatever reason it isn't releasing. & this is a corporate 10 bolt on a 1987 K5 that's mostly stock with lower miles. (118k)

 

[4x4blaze]

Welp.... Today I put the new caliper on the right side today and cruised around the city tonight. When I put it on, I spun the tire and counted the revolutions. It was roughly 3/4's of a turn before with the old caliper, and now about 1 and a half with the new caliper on the right. So a bit better. But the other side (left) is at about 3 revolutions.

Tonight after I cruised it around town, I pulled into a gas station to check on them after a fair amount of braking. When I jumped out and felt the left, I was surprised! I would consider the temperature as warm. The hub felt great and is exactly where I would like it to run at. But then I walked around the truck and felt the right.... And it was hot.... Much much hotter than the other side (and remember, this is the side with the brand new caliper) and felt like it could burn you....

What is the deal here?! Everything is new! I cannot believe something like this is giving me such a hard time. Its absolutely baffling. I could take the rubber hoses and wipe them off and they would look brand new. I honestly just cannot see one failing.

& I have never heard of this happening before throughout all of the things I have read, but is it possible for a steel hard line to rust inside and act as a check valve? My father has been tossing around this idea for a little while now, but I'm skeptical. Seems like a pain in the bass for something that may not help me. & i really don't have much confidence after replacing almost the entire brake system and continuously striking out... I JUST WANT TO DRIVE THIS THING!

easy way to see if the hose is making the brakes drag is to pump the pedal several times,then spin the wheel and feel how much drag there is--then open the bleeder screw--if its the hose,the wheel will spin freely...if not,its the caliper sticking or not releasing..

Today I gave this method a shot.. (Thanks for sharing it with me btw) I pumped the brakes up and spun the right tire. It spun 3/4's of a turn. Opened up the bleeder screw and it very slowly oozed up into my bleeder tool very slowly but stopped after it climbed about 3 inches up the tube. I then snugged the screw and spun the tire. Same exact result, 3/4's of a turn. And now with the new caliper, it is still getting red hot.... I'm beyond frustrated...
& remember, it spun freely w/o the caliper on it about 6 times... Im lost.

But thanks for the replies everyone! Much appreciated with this stupid issue.

 

[diesel4me]

The bleeder should flow a good amount of fluid out right away,not "ooze" out--I dont put anything on the bleeder screw when I do this,just let it vent to the open air...
The sluggish action of the fluid suggests to me one of the rubber hoses might be defective--new doesn't always mean "good"...todays parts quality sucks,even on critical things like brake parts...I have had brand new wheel cylinders that were seizing up enough to make the rear shoes smoke--yeah,they were only 9.99 at Autozone,and "lifetime gauranteed" ,but they were still DEFECTIVE !..

Its rare for a steel line to rust internally enough to create this problem,without it bursting from weakness--but anything is possible--dents or kinked areas at bends can block fluid flow,more so on the "release" than when the brakes are applied..

It could be the caliper too,I cannot tell from your reply if you replaced the one you suspected of sticking,or not..

Another thing to check is the wheel bearings & adjustment,but you say with the caliper off,the rotor spins freely..however,weight of the truck or tire & rim can "tilt" the rotor against the brake pads if the bearings are loose..

 

[aandpman]

I've been fighting with similar issues for quite a while now. I've gone thru multiple calipers/pads/rotors/bearings and most recently a master cylinder trying to solve it. Most of the time, it still comes down to this:

Those darn caliper Pin Bushings. I've had rebuilt calipers that you could physically SEE the pin bushing holes out of round (like the end of the ear was struck and the hole had become deformed).
I can put on a NEW caliper, and within a couple of weeks, the metal pin bushings will not slide freely thru the rubber grommets. I'd have to hammer them out. ...and YES I'd been lubing them with brake caliper grease.
I've even noticed that I can lube and install the bushings in new rubbers, push on them and they be good, then if I wait 10 minutes, they are hard to push thru. Right now I'm using the blue caliper grease. I'm looking to switch to SylGlide when I can find some. Apparently, according to some brake blogs, ANY caliper grease but SylGlide will start to swell up that rubber and make the pin bushings stick.

Finally, one day I put new rubbers in and reamed them out with a small barrel sander on my dremmel tool (it just fits perfectly). I've almost had to go TOO loose. Afterward, I lube them with caliper grease, and lube the sliding contact points on the backing plate. I've gotten to where I will now test mount them without the pads, just to see if they slide easily.

If those calipers can't slide, then when you have a rotor that is showing any runout at all, you will get that annoying vibration on the front end from pad slap....and yes, that will cause heat buildup and prevent free rotation when you're jacked up. So far I have to pull them down about once every 1.5 to 2 months and check and lube those pin bushings. If not, the K5 will gradually start giving me that stupid shimmy/bounce/pull/roughness/vibration on the front.

NOW IF I COULD JUST FIGURE OUT HOW TO MAKE THE REAR DRUMS STOP OVER-TIGHTENING AND DRAGGING.... But that's another story altogether....

I need a placard on my dash that says "It's the BRAKES stupid, It's ALWAYS the brakes" ....when I start coming up with all these ideas while I'm driving why my front is vibrating again....

 

[diesel4me]

You can remove the piece on the rear brakes that contacts the star wheel to self adjust the brakes,and just manually adjust them once in a while..I usually have too anyway even with the self adjusting parts all intact and "working",they never seem to "adjust" for me,even if I do multiple panic stops in reverse to activate them..

It would pay to be sure the star wheel adjusters were not swapped side to side somewhere along the line,that can make them tighten up the brakes every time you apply them going forward..also the E-brakes are responsible for a lot of dragging rear brakes complaints too,the "return" springs are not that beefy on even new cables that operate smoothly..I avoid using my e-brake as much as possible to avoid that..

I cant say I have had much trouble with the caliper pins sticking..
I use never-seize when I have to remove a caliper bolt on the threads and the shank,and the bushings...wire brush them clean on a bench grinder wire wheel first...

 

[JoshHefnerX]

I've had a few that were rusted or worn to the point that they didn't slide freely.

 

[Blue85]

Any chance a hardline to the sticking brake is kinked or dented? The MC creates tons of pressure and can apply through a restriction, but the return of the pads does not provide much force (I think this is the effect that gets called "check valve"). Since opening the bleeder screw doesn't free the wheel up much, it seems like residual pressure isn't the problem, but it can take several revolutions to get the pads retracted back.

If it never frees up with the bleeder open, it has to be a mechanical issue with the piston in the bore or the slide pins. Any chance your backing plate is bent or not mounted quite straight? If one of the slider bolts isn't exactly perpendicular to the backing plate, it will drag inside the caliper. When you push the piston back in with a C-clamp, is it really easy? If you assemble the caliper to the backing plate with no pads, can you slide it side to side easily?

EDIT: Oh yeah, there could also be a problem with the wheel bearings. If the bearing is loose, the weight of the tire (on jack) or truck (off jack) will side load the rotor into the pad.