Front Wheels Hot, Bearings?

[posulli88]

I rebuild my entire front axle about 1000 miles ago. I put bigger ebc brakes and calipers on as well as all new bearings, seals, and spindles. On trips longer then 25-30 ish miles I am realizing my front wheels are getting hot. I can hold my hand on it for a second or two but not much longer. The rear wheels are relatively cool to the touch.

Whats the best way to figure out if the bearings have an issue here and are causing the heat?

I have noticed if I lift off the gas the truck slows down more so then it should. So maybe it's more of a brake thing. I'll pull apart and re grease caliper pins.

[MysticRob]

Get a good infrared thermometer and point that puppy at stuff. I'd default to looking at the brakes first, as that's typically the heat generator.

[devildog80]

Agreed....sounds like front brakes not releasing all the way

[babywag]

Brakes get hot, kinda normal. Check actual temp, not unusual for them to be 3-400

[devildog80]

Or dragging.

Might have a sticky caliper, or bad brake hose?

Have seen the brake hoses from the frame to wheel breakdown inside, and fluid pushes crud down to the wheel every time brakes applied, but will not release pressure.

If both front brakes are dragging, proportioning valve or master cylinder would be suspect.

[posulli88]

I should have noted that when I rebuilt the axle. I replaced every brake like with new pre bent stainless lines, replaced the hoses, prop valve, and master cylinder. so the system should be clean. I did have issue with a couple master cylinders (leaking, bad seals) and 2 prop valves. Good call on the prop valve. Anyway to check its function?

Just raised both front wheels and they spin freely with the normal amount of very slight resistance.

[SJTD]

I would put the front axle on stands and see how the wheels feel.

Had a Dasher once. Replaced the master. All was well going to work but coming home it felt like the brakes were dragging. Got worse as I drove. Pulled over when it got really bad. Cause was the bleed port in the master was not uncovered so as the fluid heated up from driving the brakes dragged more, got hotter dragged worse...

I don't remember what the cause was, wrong master maybe but the immediate fix was to bleed the pressure off and take it easy going home. So maybe try that when they get hot. Crack a bleeder or line at the prop valve and see if you get a good squirt indicating built up pressure.

[sierrablue]

So if it's not the brakes dragging, it's entirely possible that the bearings are overheating--when you set the bearings, did you back it off the full quarter turn/to the point that the wheel spins very freely? I suppose you mentioned a very slight resistance so it's clearly been backed off. And it only needs like 50 lb-ft of torque to set it--did all of that go as it should've? And you packed the bearings well? With the front wheels off the ground, if you did fresh bearings and grease, you should be able to spin them and listen to it. If there's any feint popping or crunching, the grease has been getting too hot and things need checked on.

Do you run locking hubs? If so, any chance you left one locked and the other unlocked? Or if you have a Quadratrac that could heat up the front end more than normal.

What kind of driving have you been doing? Lots of stop-and-go or hard braking, or nice and easy with minimal stopping?

[posulli88]

Well I meant to respond to this instantly but I got logged out and couldn't remember my password, and the site wouldn't let me reset.

The front hubs are standard non locking hubs. I have done both highway driving and around city with similar results...

I opened up the hubs, checked the bearings, and checked brake friction when spinning wheel. Everything seemed normal, smooth, and properly adjusted. Went out for a longer drive and measured front wheel temps with a laser temp gauge. Was reading as high as 195F. So I guess this is ok? Its just heating up the Wheels?

I will say if I let off gas there is a noticeable loss in momentum...

[letank]

195 is a lot! something is dragging, are both sides the same temp?

How is your mileage?... not good with dragging brakes!

I have the habit of checking for wheel temp on long drive when refueling... and the hubs are barely warm to the touch!

On one of my bike with front dual disk brakes, one disk is way hotter than the other... I purged the brakes and it helped a lot. One time it was the rear brake, at night, the disk was glowing red... I had to pry the pad off with a screwdriver to keep driving and avoided using the rear brake, a purge solved the issue.

May be the brake fluid is expanding with heat when you use the brakes and for some reason, the cylinders or pads get stuck...


So purge again and release the pin at the proportioning valve before starting, some pins are push others are pull

[sierrablue]

Because it's non locking hubs and all of the bearings and such seem to check out, I wonder if there's something going on in the diff causing problems, or U joints or something seizing up, putting weird stress/heat on things. Is the axle vent plugged up, causing a buildup of heat in the axle?

How hard are you on the brakes when stopping? Not sure why you would be, but if you're putting yourself into the windshield every time, that can cause some excessive heat in the system.

The only other thing I can think, if the brakes and bearings allow it to spin freely, is if at some point the pads and/or rotors got hot once, and then became glazed over, and now they don't work properly. But I wouldn't expect that to cause excessive heat.

Assuming you don't have an O/D transmission, it's not going to glide well unless you pop it in N. How does it coast from about 55 mph, if you slip it into N?

Does it pull to one side or the other when driving, or does it pull under braking?

[posulli88]

Hoping to get to the front brakes this weekend and get them re bleed and see if that helps. Before I do that I want to confirm my brake set up is compatible. 3ish years ago when I did the entire brake system I upgraded the front brakes.I used the following parts, these are compatible correct?

_1985 CHEVROLET K20 PICKUP 5.7L 350cid V8 Calipers (JD7): I had to grind down the housing a little bit to fit the square banjo fitting in.

_EBC RK7012 Rotors from BJ's : https://www.bjsoffroad.com/EBC-RK-Se...ug_p_1877.html

_EBC Greenstuff 6000 pads : https://www.bjsoffroad.com/EBC-Green...ads_p_315.html

Those should all work together correct?