2nd Gen Non-Engine/Transmission Hot hubs after replacing front brake componants

[GAmes]

The front disks on a '97 2WD are one piece with the hubs. Last weekend I replaced both hub/rotors, both calipers, new Timpken bearings/races and the pads, then flushed/bled the system back to front with synthetic DOT 3 fluid. After a 10 mile test drive everything seemed to be good, no heat and even braking. I did not do a bed-in procedure that I just researched from issue 50. Tues day I pulled a friend's 3000 pound boat about 150 miles to a lake, but did not check the hubs for heat when we were there. On the return trip yesterday I remarked to him that he might want to get his trailer brakes checked out because they didn't seem to be working well. After dropping him & the boat at his house I drove home, about 6 miles. Roughly 20 minutes later I thought about the brakes and did a touch test on the hubs. They were pretty warm, a lot warmer than they ought to be but not blistering hot. So my question. Did I make a mistake by switching to synthetic DOT 3 since I didn't change the master cylinder (it is the original)? Both hubs are equally hot so I'm ruling out the bearings because they were packed and installed the same way I do the job every 50k miles. I'm going to go out and do the bed-in procedure this morning to see if that makes a difference.

 

[GAmes]

I did the bed in procedure, then drove about 8 miles to cool the disks. When I got home I jacked each tire off the ground and there is definite friction when rotating the wheels. Hubs are pretty warm, 110 degrees according to my IR gun. Will the MC cause this?

 

[BMelhuish]

I do not think that the master cylinder will cause this problem. There are several sources of your issue. Your brake pads are dragging and causing the rotor to heat up. Your wheel bearings are not properly installed or lubed. I honestly don't know what would be considered too hot.

 

[GAmes]

Well because it was the easiest thing to check I pulled the dust caps and backed the hub retaining nuts about 1/4 flat. They were finger tight during installation, but I needed a wrench to loosen them. As soon as the clear RTV sets up that glues the caps on (no longer available from the dealer and I can't find another source) I'll take it for a drive. Anybody have a set part #3634741 gathering dust? Too hot to me is anything much higher than ambient temp. When I'm on the road I check them every now and then and the hub is never hot.

 

[GAmes]

Using my wife's minivan to check rotor temps it appears my pads aren't the cause of the heat. I'm going to pull the hubs and check the bearings in the morning. I'm still wondering about the synthetic DOT 3 though.

 

[NIsaacs]

If you know your grease cap size, this link might help. Note all the sizes on the left of the page.

http://r.search.yahoo.com/_ylt=A0SO8zKYcV5VyxoArIhXNyoA;_ylu=X3oDMTE3Ym1yMTlxBGNvbG8DZ3ExBHBvcwMzBHZ0aWQDVklQNTc4XzEEc2VjA292LXRvcA--/RV=2/RE=1432281624/RO=10/RU=http%3a%2f%2f10403.r.msn.com%2f%3fld%3dd3kcHAXsF1a6asneDfffU2aTVUCUwuPp0LbbYCnZiym1rdCOqLFUw_n6i3zVvzS3Mas0wLc3IEK1TXz6CP8S-QWrIdQER2dpoRFX2emUrKM765zq3rDfNs_dXRUfDWJ0k7ew1wr5GlgGvsnEW2h-DOHVsjFddURqzn82P6-nEDeGaTdiiJ%26u%3dhttp%253a%252f%252fwww.etrailer.com%252fdept-pg-Grease_Caps.aspx/RK=0/RS=jZ5DZ4ynQvNJkuZQBqbMdh6FfDs-?p=dust+caps+for+wheel+bearings

Nick

 

[GAmes]

Thanks Nick. For some reason my searches came up empty.

 

[BMelhuish]

As far as checking against your wife's minivan, you may be comparing apples and oranges. Somewhere I remember that there is a torque rating on the front wheel bearings. You torque it to that value and back off 1/4 turn. I don't think I've ever done it that way though. We just snugged them up firmly to seat the bearings and backed it off about a 1/4 turn. Someone here should have a manual to tell you.

What type of grease did you use to repack the bearings? Is the synthentic compatible with regular stuff? I really don't see that as the issue.

 

[GAmes]

Comparing disk temps is all I can go by. The retaining nut is finger tight (tapered bearings), the grease is the same Valvoline high temp that I have used for the last million miles. I've had a factory service manual since the truck had 100 miles on it. The synthetic brake fluid bottle (Prestone) states it is compatible with all DOT 3 fluids. I removed the calipers today and the hubs spin freely. I pulled them anyway to inspect the bearings. All I can determine is the new calipers are slightly tighter than the old ones.

 

[BMelhuish]

I not certain that you need to worry about this. Look in your manual as to how to set the front bearings and the torque. Do it that way and run it awhile. I think you'll find that it isn't causing much of an issue. As an aside I'm fairly certain that "finger tight" is not sufficient. Either do it the old fashioned way or by the manual. The axle nut is recessed enough that you'll need a socket of an appropriate size to do the job.

 

[GAmes]

Thanks, but tightening the nut to about 50 lbs of TQ and rotating the hub to seat the bearings, then backing the nut off and tighten finger tight IS the old fashioned way.

 

[BMelhuish]

I'm not arguing with you except we never used a torque wrench-depending on your age of course. However, I never used my fingers. I just backed up a 1/4 turn, checked it, and put in the key. If that was finger tight, I truly don't know.

 

[B.G. Smith]

Don't see the brake fluid causing the brakes to heat up. Heavy wheel bearin grease or t0o much grease will cause heat. There will always be a little resistance to rotating the tire with disc brakes, will probably be less as the pads smooth out. bg

 

[GAmes]

I hope so BG. I drove 55 miles, picked up a 31 ft TT and came home. The hubs were a lot hotter than normal. I do the remove/inspect/repack/reinstall every 50k. I've never had this happen before. I'm going to put 10-15k miles on it in the next few weeks. If it isn't normal by then, I guess I'll change the MC.

 

[JR]

Hey Gary, what brake rotors have you found to work the best on your truck? I'm about to do bearings and rotors. They're a PIA on the 4wd and I dont want to do this again anytime soon.

 

[GAmes]

Believe it or not, I got about 700k out of a set of AutoZone hub/rotors. About halfway through I replaced the pads, I use their semi-metallic. This time I caught a sale at NAPA and bought theirs, and another set of AZ pads.

I guess BG was right, after 1100 miles and some driving in the rain every thing is cool as it should be.

 

[mwilson]

You were hyper-sensitive to the issue, I do the same thing after I have scattered parts all over the driveway and put it all back together.

I figured given the miles that you and that truck have traveled and all the related repairs that you have successfully performed the chances were good it was assembled correctly.
It was just a little tight.

Glad it is all good.

Mike.

 

[AH64ID]

After a couple of wheel bearing issues last year I was VERY sensitive to temp and road noise/feel... but after a while the cooled down quite a bit so they must run a little warmer when new which is understandable.