| RH Front Brake overheat [message #60062] |
Wed, 14 October 2009 10:35  |
Jon payne
Messages: 495
Registered: May 2008
Karma: 1
|
Senior Member |
|
|
Hi everyone,
Yesterday I was took the GMC out of the barn and drove it to the house to finish up some interior work. The barn is about 9 miles from the house and about half way home I started to smell what seemed to be brake burning smell. When I got it to the house and backed in the drive my brake light came on and the pedal went to the floor.
I jump out and saw smoke coming from the RH wheel. No doubt I have a locked up caliper. Crap! It got hot enough to soften up/melt the Alcoa look-a-like plastic wheel cover. So as a result I will be replacing both calipers and the front brake lines (and the melted wheel cover).
I am concerned about the bearings in the hub. This summer I sent both hubs to Dave Lenzi and he did his magic on them (so I got the grease fitting installed as well). Anyway do you think the high heat generated from the dragging brake could have caused any damage to the bearings? I'm thinking not do to the relative short drive and the fact it is packed with Mobile 1. My thought is to flush out the grease via the zerk fitting and see if the grease has been discolored. If it is still nice and red then I presume the bearings are okay.
Any thoughts/comments would be appreciated!
Jon
Jon Payne
76 Palm Beach
Westfield,IN
|
|
|
|
| Re: [GMCnet] RH Front Brake overheat [message #60065 is a reply to message #60062] |
Wed, 14 October 2009 10:49  |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
|
Senior Member |
|
|
Look at both ends of the knuckle and see how the seals are holding the grease.
On Wed, Oct 14, 2009 at 8:35 AM, Jon Payne <embrep@sbcglobal.net> wrote:
>
>
> Hi everyone,
>
> Yesterday I was took the GMC out of the barn and drove it to the house to finish up some interior work. The barn is about 9 miles from the house and about half way home I started to smell what seemed to be brake burning smell. When I got it to the house and backed in the drive my brake light came on and the pedal went to the floor.
>
> I jump out and saw smoke coming from the RH wheel. No doubt I have a locked up caliper. Crap! It got hot enough to soften up/melt the Alcoa look-a-like plastic wheel cover. So as a result I will be replacing both calipers and the front brake lines (and the melted wheel cover).
>
> I am concerned about the bearings in the hub. This summer I sent both hubs to Dave Lenzi and he did his magic on them (so I got the grease fitting installed as well). Anyway do you think the high heat generated from the dragging brake could have caused any damage to the bearings? I'm thinking not do to the relative short drive and the fact it is packed with Mobile 1. My thought is to flush out the grease via the zerk fitting and see if the grease has been discolored. If it is still nice and red then I presume the bearings are okay.
>
> Any thoughts/comments would be appreciated!
>
>
> Jon
> --
> Jon Payne/
> 76 Palm Beach/
> Westfield,IN
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
|
|
|
|
| Re: [GMCnet] RH Front Brake overheat [message #60066 is a reply to message #60062] |
Wed, 14 October 2009 11:07 |
Tin Gerbil
Messages: 236
Registered: October 2006
Location: Vancouver Island, B.C.
Karma: 0
|
Senior Member |
|
|
Jon;
Look carefully at the boots on the upper and lower ball joints. If they
are distorted from the heat, the bearing seal may be damaged. You have
to weigh the cost of a breakdown on the road vs the cost of taking the
knuckle off and pulling the bearings now.
Gordon
Jon Payne wrote:
>
> Hi everyone,
>
> Yesterday I was took the GMC out of the barn and drove it to the
> house to finish up some interior work. The barn is about 9 miles from
> the house and about half way home I started to smell what seemed to
> be brake burning smell. When I got it to the house and backed in the
> drive my brake light came on and the pedal went to the floor.
>
> I jump out and saw smoke coming from the RH wheel. No doubt I have a
> locked up caliper. Crap! It got hot enough to soften up/melt the
> Alcoa look-a-like plastic wheel cover. So as a result I will be
> replacing both calipers and the front brake lines (and the melted
> wheel cover).
>
> I am concerned about the bearings in the hub. This summer I sent both
> hubs to Dave Lenzi and he did his magic on them (so I got the grease
> fitting installed as well). Anyway do you think the high heat
> generated from the dragging brake could have caused any damage to the
> bearings? I'm thinking not do to the relative short drive and the
> fact it is packed with Mobile 1. My thought is to flush out the
> grease via the zerk fitting and see if the grease has been
> discolored. If it is still nice and red then I presume the bearings
> are okay.
>
> Any thoughts/comments would be appreciated!
>
>
> Jon
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Gordon
'74 Canyon Lands "Tin Gerbil"
Vancouver Island, B.C.
|
|
|
|
| Re: [GMCnet] RH Front Brake overheat [message #60069 is a reply to message #60066] |
Wed, 14 October 2009 11:26 |
Jon payne
Messages: 495
Registered: May 2008
Karma: 1
|
Senior Member |
|
|
Thanks for input. My first reaction when I saw how hot the brakes got , enough to soften the wheel cover, was to pull the hub off and send it back to Dave L for inspection/re-lube. I did send him an email asking for his advise as well.
Thanks again,
Jon
Jon Payne
76 Palm Beach
Westfield,IN
|
|
|
|
| Re: [GMCnet] RH Front Brake overheat [message #60075 is a reply to message #60069] |
Wed, 14 October 2009 12:00 |
Ron
Messages: 250
Registered: February 2004
Location: Conifer, Colorado
Karma: 0
|
Senior Member |
|
|
Jon..
Saw Dave at the Pueblo rally.. He is on an extended trip through the southwest.. He said about 4 weeks.. Don't know if he has internet access while on the road..
Just didn't want you to think he was ignoring you..
Ron
now a P.O.
Conifer, CO
|
|
|
|
| Re: [GMCnet] RH Front Brake overheat [message #60077 is a reply to message #60066] |
Wed, 14 October 2009 12:17 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
|
Senior Member |
|
|
I would grease the bearings before moving the coach again. It is not that difficult and will not take that long.
You will be surprised at how little, if any, old red Mobil 1 grease will come out of them. They do nto hold much grease in the first place.
I had a problem with Mobil 1 turning from grease consistency to oil and running out of the bearings. I suggest you use an Extreme Pressure Moly fortified synthetic grease.
Valvoline Syn-Power is a good one. It is available at AutoZone. The moly will give you another layer of lubrication / protection if the grease ever get too hot again. Also due to the difference in color you will be able to see when all of the old grease is replaced with new. I talked to Dave Lenzi about using the Valvoline SynPower and he had no problems with it.
http://www.valvoline.com/pdf/SynPower_Grease.pdf
http://www.valvoline.com/products/brands/synpower/grease/63
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
|
|
|
|
| Re: [GMCnet] RH Front Brake overheat [message #60081 is a reply to message #60077] |
Wed, 14 October 2009 12:37 |
Jon payne
Messages: 495
Registered: May 2008
Karma: 1
|
Senior Member |
|
|
Thanks again all. I guess for now I will relube as Ken suggested and then wait until I hear back from Dave. I can't keep the MH at the house very long so I guess I will relube, replace the calipers and hoses and back to the barn.
I'll be taking off the wheel later today and if I find anything significant I will let you guys know.
Jon
Jon Payne
76 Palm Beach
Westfield,IN
|
|
|
|
| Re: RH Front Brake overheat [message #60091 is a reply to message #60062] |
Wed, 14 October 2009 15:57 |
Jon payne
Messages: 495
Registered: May 2008
Karma: 1
|
Senior Member |
|
|
Here is an update. I just took a look at the bearing seals for damage. First the ball joint dust boots are not damaged from the heat however looking at the bearing grease seal it appears that the grease liquefied and dripped passed the seal (click on below link for picture). As you will see in the picture the grease liquefied after I parked the MH in the driveway.
I'm thinking I really should remove the hub and send it to Dave L. Any thoughts as to the condition of the bearings? The bearings have less than 300 miles on them. I am hoping I can re-grease via the zerk fitting, get it back to the barn and deal with it next spring.
http://www.gmcmhphotos.com/photos/showphoto.php?photo=31162&nocache=1
Comments appreciated.
Jon
Jon Payne
76 Palm Beach
Westfield,IN
|
|
|
|
| Re: [GMCnet] RH Front Brake overheat [message #60093 is a reply to message #60091] |
Wed, 14 October 2009 16:33 |
Rick Denney
Messages: 430
Registered: January 2004
Karma: 0
|
Senior Member |
|
|
Jon Payne writes...
> I'm thinking I really should remove the hub and send it to Dave L.
> Any thoughts as to the condition of the bearings? The bearings have
> less than 300 miles on them. I am hoping I can re-grease via the
> zerk fitting, get it back to the barn and deal with it next spring.
> http://www.gmcmhphotos.com/photos/showphoto.php?photo=31162&nocache=1
I might remove the hub just to check the seal, but you can inspect the
face seal where it rubs against the stub-axle base and if it is still
soft and undistorted, I wouldn't worry about it.
Mobil 1 grease has a tendency to separate like this even without the
overheat, so I would not really worry about it. But I would change the
grease for the Valvoline SynPower that Ken recommended. The moly
fortification will add considerable protection against temperature
extremes.
I seriously doubt you damaged the bearings from brake heat. The heat
required to do that would have discolored the metal on the rotor. The
worst possible damage would be to cook out the oil and then run it
unlubricated, but I don't think you ran enough miles to do that.
I would just inspect that rear seal, inject all new grease using
SynPower, and keep an eye on it. If the seal doesn't leak, then it's
okay.
Rick "who loves Mobil 1 oil but not the grease" Denney
'73 230 Ex-Glacier "Jaws"
Northern Virginia
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
'73 Glacier 230 "Jaws"
|
|
|
|
|
|
| Re: [GMCnet] RH Front Brake overheat [message #60098 is a reply to message #60062] |
Wed, 14 October 2009 17:25 |
 |
USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
|
Senior Member |
|
|
Jon,
I've interspersed some questions / comments in CAPS in your messages below:
Regards,
Rob Mueller
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
'75 Avion - USA - The Parts Coach TZE 365V100324
-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of Jon Payne
Sent: Thursday, October 15, 2009 2:35 AM
To: gmclist@temp.gmcnet.org
Subject: [GMCnet] RH Front Brake overheat
Hi everyone,
Yesterday I was took the GMC out of the barn and drove it to the house to
finish up some interior work. The barn is about 9 miles from the house and
about half way home I started to smell what seemed to be brake burning
smell.
WHEN YOU NOTICED THE SMELL COULD YOU FEEL ANTHING IN THE STEERING, I.E. DID
THE COACH PULL TO THE RIGHT?
When I got it to the house and backed in the drive my brake light came on
and the pedal went to the floor.
THE HEAT BOILED ALL THE FLUID OUT OF THE CALIPER; HOW'S THAT FOR
DEMONSTRATING AN ACUTE GRASP ON THE OBVIOUS! ;-)
I jump out and saw smoke coming from the RH wheel.
HOW LONG DID THE SMOKE PERSIST?
No doubt I have a locked up caliper. Crap! It got hot enough to soften
up/melt the Alcoa look-a-like plastic wheel cover.
COULD YOU POST SOME PICTURES OF THE PLASTIC WHEEL COVER? IS THE DEFORMATION
CLOSE TO THE CENTER OF THE WHEEL COVER OR OUT NEAR THE DISK?
So as a result I will be replacing both calipers and the front brake lines
(and the melted wheel cover).
GOOD IDEA! WHILE YOU'RE AT IT YOU MIGHT WANT TO CONSIDER REPLACING THE
RUBBER LINES WITH BRAIDED STAINLESS STEEL,
I am concerned about the bearings in the hub. This summer I sent both hubs
to Dave Lenzi and he did his magic on them (so I got the grease fitting
installed as well). Anyway do you think the high heat generated from the
dragging brake could have caused any damage to the bearings? I'm thinking
not do to the relative short drive and the fact it is packed with Mobile 1.
My thought is to flush out the grease via the zerk fitting and see if the
grease has been discolored. If it is still nice and red then I presume the
bearings are okay.
I AGREE WITH YOU. DOES MOBIL 1 DISCOLOR WITH HEAT?
Any thoughts/comments would be appreciated!
Jon
--
Jon Payne/
76 Palm Beach/
Westfield,IN
-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of Jon Payne
Sent: Thursday, October 15, 2009 7:57 AM
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] RH Front Brake overheat
Here is an update. I just took a look at the bearing seals for damage. First
the ball joint dust boots are not damaged from the heat however looking at
the bearing grease seal it appears that the grease liquefied and dripped
passed the seal (click on below link for picture). As you will see in the
picture the grease liquefied after I parked the MH in the driveway.
I'm thinking I really should remove the hub and send it to Dave L. Any
thoughts as to the condition of the bearings? The bearings have less than
300 miles on them. I am hoping I can re-grease via the zerk fitting, get it
back to the barn and deal with it next spring.
http://www.gmcmhphotos.com/photos/showphoto.php?photo=31162&nocache=1
I LOOKED AT THESE PICTURES AND OTHER THAN THE TRACES OF LIQUIFIED MOBIL 1 I
DON'T SEE ANYTHING THAT INDICATES THE AREA WAS EXPOSED TO HIGH TEMPERATURES.
IT MAY NOT BE AN INDICATOR OF ANYTHING BUT THE PAINT IS INTACT AND NOT
BLISTERED.
Comments appreciated.
HAVING SAID ALL THIS YOU STILL MIGHT WANT TO PULL THE HUB AND KNUCKLE OFF
FOR PEACE OF MIND AND DISASSEMBLE THEM FAR ENOUGH TO INSPECT THE BEARINGS.
ARE THERE ANY GMC OWNERS NEAR BY THAT COULD HELP YOU?
Jon
--
Jon Payne/
76 Palm Beach/
Westfield, IN
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
|
|
|
|
| Re: [GMCnet] RH Front Brake overheat [message #60101 is a reply to message #60098] |
Wed, 14 October 2009 18:28 |
Jon payne
Messages: 495
Registered: May 2008
Karma: 1
|
Senior Member |
|
|
Hi Rob,
Thanks for your comments. See below answers to your questions:
Q: WHEN YOU NOTICED THE SMELL COULD YOU FEEL ANTHING IN THE
STEERING, I.E. DID THE COACH PULL TO THE RIGHT?
A: I never noticed any pulling to right of left while driving or
braking.
Q: HOW LONG DID THE SMOKE PERSIST?
A: Not really sure, probably around 10 minutes or so. Maybe less.
Q: COULD YOU POST SOME PICTURES OF THE PLASTIC WHEEL COVER? IS THE
DEFORMATION CLOSE TO THE CENTER OF THE WHEEL COVER OR OUT NEAR
THE DISK?
A: I just posted some pics of the rotors and wheel cover (click on
the link below). As you will see the deformation of the wheel
cover was near the rotor.
http://www.gmcmhphotos.com/photos/showphoto.php?photo=31180
Jon Payne
76 Palm Beach
Westfield,IN
|
|
|
|
|
|
|
|
|
|
| Re: RH Front Brake overheat [message #60115 is a reply to message #60091] |
Wed, 14 October 2009 20:38 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
|
Senior Member |
|
|
It would be interesting to look at the other side and see if you also see the oily leakage. Mobil 1 tend to do that and maybe the oil you are seeing is not from an overheat condition at all.
Ken H. and Rick Denny pretty much said everything I had to say so I'll just second their recommendations.
Dump the Mobil One and go with the moly fortified synthetic grease from Valvoline.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
|
|
|
|
| Re: RH Front Brake overheat [message #60124 is a reply to message #60115] |
Wed, 14 October 2009 21:17 |
Jon payne
Messages: 495
Registered: May 2008
Karma: 1
|
Senior Member |
|
|
Thanks everyone for your comments and suggestions!!
FYI... I did check the other side and there was no grease leaking. Dry as bone. I will post some more pics as I tear into it if there is anything interesting to share.
My best regards to all!
Jon
Jon Payne
76 Palm Beach
Westfield,IN
|
|
|
|
| Re: [GMCnet] RH Front Brake overheat [message #60134 is a reply to message #60101] |
Wed, 14 October 2009 21:57 |
|
USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
|
Senior Member |
|
|
Jon,
I'd guess that the hub caps deformed from the heat coming through the holes
in the wheels. The shape of the deformation seems to support that SWAG!
The picture of the RH disk (31180) shows discoloration of the flange that
the bolts go through to attach the disk to the hub. It appears to be darkest
around the empty hole at the 12:00 position. It sure looks like heat
discoloration. Note that the area closest to the disk appears to be a blue /
black (got hotter) where as the area closest to the hub is brownish
(cooler).
The picture of the LH disk (31179) shows some discoloration around the bolt
at the 1:00 position, however, from there down to the bolt at the 4:00
position the metal is bright shiny silver.
The flange is the area that the heat would have been transferred from the
disk to the hub/bearing.
1) how hot did it get to result in the discoloration?
2) how much of that heat got transferred into the bearings?
I did a Google search to try and find out how much heat it takes to
discolour cast iron but couldn't come up with anything. Maybe someone else
will have better luck!
Regards,
Rob Mueller
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
'75 Avion - USA - The Parts Coach TZE 365V100324
-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of Jon Payne
Sent: Thursday, October 15, 2009 10:29 AM
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] RH Front Brake overheat
Hi Rob,
Thanks for your comments. See below answers to your questions:
Q: WHEN YOU NOTICED THE SMELL COULD YOU FEEL ANTHING IN THE
STEERING, I.E. DID THE COACH PULL TO THE RIGHT?
A: I never noticed any pulling to right of left while driving or
braking.
Q: HOW LONG DID THE SMOKE PERSIST?
A: Not really sure, probably around 10 minutes or so. Maybe less.
Q: COULD YOU POST SOME PICTURES OF THE PLASTIC WHEEL COVER? IS THE
DEFORMATION CLOSE TO THE CENTER OF THE WHEEL COVER OR OUT NEAR
THE DISK?
A: I just posted some pics of the rotors and wheel cover (click on
the link below). As you will see the deformation of the wheel
cover was near the rotor.
http://www.gmcmhphotos.com/photos/showphoto.php?photo=31180
--
Jon Payne/
76 Palm Beach/
Westfield,IN
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
|
|
|
|
| Re: RH Front Brake overheat [message #60149 is a reply to message #60124] |
Thu, 15 October 2009 00:47 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
|
Senior Member |
|
|
| Jon Payne wrote on Wed, 14 October 2009 21:17 |
Thanks everyone for your comments and suggestions!!
FYI... I did check the other side and there was no grease leaking. Dry as bone. I will post some more pics as I tear into it if there is anything interesting to share.
My best regards to all!
Jon
|
Oh well. It was just a thought.
I would grease it, drive it, and watch it over the next few thousand miles.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
|
|
|
|
| Re: [GMCnet] RH Front Brake overheat [message #60179 is a reply to message #60101] |
Thu, 15 October 2009 09:39 |
Rick Denney
Messages: 430
Registered: January 2004
Karma: 0
|
Senior Member |
|
|
Jon Payne writes...
> A: I just posted some pics of the rotors and wheel cover (click on
> the link below). As you will see the deformation of the wheel
> cover was near the rotor.
> http://www.gmcmhphotos.com/photos/showphoto.php?photo=31180
Okay, those pictures help a lot. No, I don't think the bearings will
be any problem at all. I'm with Rob that the deformation of the wheel
cover was caused by heated air and radiation from the overheated
brake, not by conduction through the metal parts. I think I interpret
the pictures differently than Rob. The discoloration around the hole
in the rotor seems to me more a matter of where surface rust has grown
versus where it hasn't. I don't really see heat damage. In any case,
the heat would have discolored the pad area first (the sources of the
heat), and then extended into the center of the rotor, not the other
way around. I agree with others that the likely culprit was an old
brake hose that has collapsed internally and become a check velve. But
you said you were replacing those already, so I didn't mention it
specially. I do agree that the stainless-braid hoses hold pressure
better and are more durable. Make sure to fully bleed the brake system
so that you replace all the fluid, not just fill up the new caliper.
Rick "sticking with his earlier comments" Denney
'73 230 Ex-Glacier "Jaws"
Northern Virginia
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
'73 Glacier 230 "Jaws"
|
|
|
|
GMCforum
Search
Help
Register
Login
Home
