Home » Public Forums » GMCnet » Brakes (Brake/Wheel Temps too High)
| Brakes [message #310045] |
Mon, 07 November 2016 15:00  |
Nicholls
Messages: 36
Registered: January 2008
Location: Pensacola, FL
Karma: 0
|
Member |
|
|
Started to a rally in July, got about 20 miles and stopped to check wheel temps. Three of four rear drums were above 350d. There was no issue with front discs. I have never before seen over 150d. I returned home and rears seemed to be adjusted to tight (don't know how or why). I am pretty anal about checking and no prior indications have been noted.
I pulled one, RRF, and it seemed to be opening and closing as it should. I backed off all adjusters until just barely a scrape could be heard. I did a test run today, 11/7,. Initial readings were ok. On returning home, I checked them again and got the following readings: LF -500d, RF - 500d, RRF - 200d, RRR - 113d, LRF - 260d, and LRR - 200. Current mileage is 96836.
History:
Mar. 2016 at the Dothan GMC rally, I found out that my master cylinder to booster plate had been flattened out. Removed it and replaced with the correct one with a bend in it. Pedal was higher.
Sept. 2013 at 88400 miles, I replaced the master cylinder, the boogie flex lines, and installed 80 mm calipers and new hoses.
Sept. 2012 at 85285 miles, I rebuilt rear drum brakes with shoes, cylinders and spring sets.
I would appreciate any ideas on what is going on.
John Nicholls,
78 Royale w/455
Pensacola, FL
|
|
|
|
| Re: [GMCnet] Brakes [message #310046 is a reply to message #310045] |
Mon, 07 November 2016 15:23  |
emerystora
Messages: 4442
Registered: January 2004
Karma: 13
|
Senior Member |
|
|
I would suggest that you check the pin that goes from the booster to the master cylinder. If it is too long (no clearance at the end) then it could be closing the port that allows the brake fluid to return to the master cylinder when releasing the brake pedal.
This could cause constant pressure on the rear wheel cylinders that could cause drag and overheating.
If you find this is not the problem then you should probably replace the master cylinder.
Emery Stora
77 Kingsley
Frederick, CO
> On Nov 7, 2016, at 2:00 PM, John Nicholls wrote:
>
> Started to a rally in July, got about 20 miles and stopped to check wheel temps. Three of four rear drums were above 350d. There was no issue with
> front discs. I have never before seen over 150d. I returned home and rears seemed to be adjusted to tight (don't know how or why). I am pretty anal
> about checking and no prior indications have been noted.
>
> I pulled one, RRF, and it seemed to be opening and closing as it should. I backed off all adjusters until just barely a scrape could be heard. I did
> a test run today, 11/7,. Initial readings were ok. On returning home, I checked them again and got the following readings: LF -500d, RF - 500d, RRF
> - 200d, RRR - 113d, LRF - 260d, and LRR - 200. Current mileage is 96836.
>
> History:
> Mar. 2016 at the Dothan GMC rally, I found out that my master cylinder to booster plate had been flattened out. Removed it and replaced with the
> correct one with a bend in it. Pedal was higher.
> Sept. 2013 at 88400 miles, I replaced the master cylinder, the boogie flex lines, and installed 80 mm calipers and new hoses.
> Sept. 2012 at 85285 miles, I rebuilt rear drum brakes with shoes, cylinders and spring sets.
>
> I would appreciate any ideas on what is going on.
> --
> John Nicholls,
> 78 Royale w/455
> Pensacola, FL
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
|
|
|
|
| Re: [GMCnet] Brakes [message #310048 is a reply to message #310046] |
Mon, 07 November 2016 16:08 |
Dolph Santorine
Messages: 1236
Registered: April 2011
Location: Wheeling, WV
Karma: -41
|
Senior Member |
|
|
John
It's fairly easy to check
Put the rear up on jack stands so you can spin the tires.
See how they spin.
Start it. Engage brakes a few times and see if they spin.
You can remove the MC to get to the pin without breaching the hydraulics. Just remove the bolts.
You can then clay off the pin for the right length
JWIWD.
Dolph Santorine
DE N8JPC
Wheeling, West Virginia
1977 ex-Palm Beach TZE167V100820
1-ton, Sullybuilt Bags, Reaction Arms, 3.70 LSD, Manny Transmission, EV-6010,
> On Nov 7, 2016, at 4:23 PM, Emery Stora wrote:
>
> I would suggest that you check the pin that goes from the booster to the master cylinder. If it is too long (no clearance at the end) then it could be closing the port that allows the brake fluid to return to the master cylinder when releasing the brake pedal.
> This could cause constant pressure on the rear wheel cylinders that could cause drag and overheating.
>
> If you find this is not the problem then you should probably replace the master cylinder.
>
> Emery Stora
> 77 Kingsley
> Frederick, CO
>
>> On Nov 7, 2016, at 2:00 PM, John Nicholls wrote:
>>
>> Started to a rally in July, got about 20 miles and stopped to check wheel temps. Three of four rear drums were above 350d. There was no issue with
>> front discs. I have never before seen over 150d. I returned home and rears seemed to be adjusted to tight (don't know how or why). I am pretty anal
>> about checking and no prior indications have been noted.
>>
>> I pulled one, RRF, and it seemed to be opening and closing as it should. I backed off all adjusters until just barely a scrape could be heard. I did
>> a test run today, 11/7,. Initial readings were ok. On returning home, I checked them again and got the following readings: LF -500d, RF - 500d, RRF
>> - 200d, RRR - 113d, LRF - 260d, and LRR - 200. Current mileage is 96836.
>>
>> History:
>> Mar. 2016 at the Dothan GMC rally, I found out that my master cylinder to booster plate had been flattened out. Removed it and replaced with the
>> correct one with a bend in it. Pedal was higher.
>> Sept. 2013 at 88400 miles, I replaced the master cylinder, the boogie flex lines, and installed 80 mm calipers and new hoses.
>> Sept. 2012 at 85285 miles, I rebuilt rear drum brakes with shoes, cylinders and spring sets.
>>
>> I would appreciate any ideas on what is going on.
>> --
>> John Nicholls,
>> 78 Royale w/455
>> Pensacola, FL
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
|
|
|
|
| Re: Brakes [message #310061 is a reply to message #310045] |
Mon, 07 November 2016 20:25 |
 |
Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
|
Senior Member |
|
|
John,
I too frequently check bearing and brake temperatures.
You say the first check was OK, but give no data. Engineers hate that. We want all the data, even if you think it doesn't matter. It would matter in this case because if the master cylinder is not a real OE (with 1/2 thick ears), then there is a lot that can be wrong. Having it not release is one. It may have taken the first stop to build the pressure in the system.
If you want to see if the pressure is releasing, that is easy but messy. With the coach cold, crack the lines loose at the master cylinder. They might seep, but should not drip. Start the engine, lean on the brakes a good time or two and shut down. By the time you get back up front, there should be no line pressure in the front brakes (the rear of the master cylinder) and maybe very little in the rear.
One of the things that does cause brake problems with the drum rear is that the self adjusters are never exercised. They can work. You have to make them work by stopping hard in reverse (and rearranging everything in the cabinets). Many people never stop hard enough in reverse to make this happen.
Matt
Nicholls wrote on Mon, 07 November 2016 16:00Started to a rally in July, got about 20 miles and stopped to check wheel temps. Three of four rear drums were above 350d. There was no issue with front discs. I have never before seen over 150d. I returned home and rears seemed to be adjusted to tight (don't know how or why). I am pretty anal about checking and no prior indications have been noted.
I pulled one, RRF, and it seemed to be opening and closing as it should. I backed off all adjusters until just barely a scrape could be heard. I did a test run today, 11/7,. Initial readings were ok. On returning home, I checked them again and got the following readings: LF -500d, RF - 500d, RRF - 200d, RRR - 113d, LRF - 260d, and LRR - 200. Current mileage is 96836.
History:
Mar. 2016 at the Dothan GMC rally, I found out that my master cylinder to booster plate had been flattened out. Removed it and replaced with the correct one with a bend in it. Pedal was higher.
Sept. 2013 at 88400 miles, I replaced the master cylinder, the boogie flex lines, and installed 80 mm calipers and new hoses.
Sept. 2012 at 85285 miles, I rebuilt rear drum brakes with shoes, cylinders and spring sets.
I would appreciate any ideas on what is going on.
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
|
|
|
|
| Re: [GMCnet] Brakes [message #310063 is a reply to message #310045] |
Mon, 07 November 2016 21:10 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
|
Senior Member |
|
|
When was the last time you replaced the rear rubber hose and is your
parking brake cable loose?
On Mon, Nov 7, 2016 at 1:00 PM, John Nicholls wrote:
> Started to a rally in July, got about 20 miles and stopped to check wheel
> temps. Three of four rear drums were above 350d. There was no issue with
> front discs. I have never before seen over 150d. I returned home and rears
> seemed to be adjusted to tight (don't know how or why). I am pretty anal
> about checking and no prior indications have been noted.
>
> I pulled one, RRF, and it seemed to be opening and closing as it should. I
> backed off all adjusters until just barely a scrape could be heard. I did
> a test run today, 11/7,. Initial readings were ok. On returning home, I
> checked them again and got the following readings: LF -500d, RF - 500d, RRF
> - 200d, RRR - 113d, LRF - 260d, and LRR - 200. Current mileage is 96836.
>
> History:
> Mar. 2016 at the Dothan GMC rally, I found out that my master cylinder to
> booster plate had been flattened out. Removed it and replaced with the
> correct one with a bend in it. Pedal was higher.
> Sept. 2013 at 88400 miles, I replaced the master cylinder, the boogie flex
> lines, and installed 80 mm calipers and new hoses.
> Sept. 2012 at 85285 miles, I rebuilt rear drum brakes with shoes,
> cylinders and spring sets.
>
> I would appreciate any ideas on what is going on.
> --
> John Nicholls,
> 78 Royale w/455
> Pensacola, FL
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
|
|
|
|
| Re: Brakes [message #310149 is a reply to message #310045] |
Wed, 09 November 2016 09:44 |
Nicholls
Messages: 36
Registered: January 2008
Location: Pensacola, FL
Karma: 0
|
Member |
|
|
Gentlemen, I thank you for the input.
Since the last thing done was the bracket (mc to booster)and since it now appears to be affecting both front and rear, I will start with the pin. The mystifying part there is that the only trip since Dothan was to Bean Station (1000 miles) with no problems noted. I can't believe that I didn't check the temps. Guess I should start keeping records.
Dolph, please expand on the clay method or link me to it.
Matt, first readings were RRF 175, RRR 115, LRR ?, LRF 225. Dumb me didn't think the front was involved and didn't check.
JimK, I never use the parking brake for fear they won't release. Rear flex lines were replaced Sept. 2013.
John Nicholls,
78 Royale w/455
Pensacola, FL
|
|
|
|
|
|
| Re: [GMCnet] Brakes [message #310152 is a reply to message #310149] |
Wed, 09 November 2016 10:33 |
Dolph Santorine
Messages: 1236
Registered: April 2011
Location: Wheeling, WV
Karma: -41
|
Senior Member |
|
|
John:
Ken’s gizmo is brilliant, and worth the time.
If you know the clearance you want, you put a piece of clay in between the pin and the MC.
If it’s pressing, the pin displaces the clay completely.
You then take the length of the pin down in small increments until you have the clearance you want, and you’ll be able to measure the clay.
Here’s how it’s used on engine assembly:
http://www.enginelabs.com/engine-tech/engine-blueprinting-how-to-check-piston-to-valve-clearance/
The other gizmo is worth the time on the lathe.
Dolph
DE N8JPC
Wheeling, West Virginia
1977 26’ ex-PalmBeach
1-Ton, Sullybilt Bags, Reaction Arms, 3.70 LSD, Manny Transmission, EV-6010
“The Aluminum and Fiberglass Mistress"
> On Nov 9, 2016, at 10:44 AM, John Nicholls wrote:
>
> Gentlemen, I thank you for the input.
> Since the last thing done was the bracket (mc to booster)and since it now appears to be affecting both front and rear, I will start with the pin. The
> mystifying part there is that the only trip since Dothan was to Bean Station (1000 miles) with no problems noted. I can't believe that I didn't check
> the temps. Guess I should start keeping records.
>
> Dolph, please expand on the clay method or link me to it.
> Matt, first readings were RRF 175, RRR 115, LRR ?, LRF 225. Dumb me didn't think the front was involved and didn't check.
> JimK, I never use the parking brake for fear they won't release. Rear flex lines were replaced Sept. 2013.
> --
> John Nicholls,
> 78 Royale w/455
> Pensacola, FL
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
|
|
|
|
| Re: Brakes [message #310161 is a reply to message #310045] |
Wed, 09 November 2016 15:30 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
|
Senior Member |
|
|
Your symptoms match what mine were when the pin was too long.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
|
|
|
|
| Re: Brakes [message #310164 is a reply to message #310045] |
Wed, 09 November 2016 17:34 |
C Boyd
Messages: 2629
Registered: April 2006
Karma: 18
|
Senior Member |
|
|
John, have you changed your email address?
C. Boyd
76 Crestmont
East Tennessee
|
|
|
|
| Re: Brakes [message #310166 is a reply to message #310149] |
Wed, 09 November 2016 18:24 |
|
Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
|
Senior Member |
|
|
Nicholls wrote on Wed, 09 November 2016 10:44Gentlemen, I thank you for the input.
<snip>
Matt, first readings were RRF 175, RRR 115, LRR ?, LRF 225. Dumb me didn't think the front was involved and didn't check.
John,
I have had reaction arms on the rear for enough years to forget the spread front/back before that, but the the side to side was never 50°. Maybe 30°, and the spread at the other pair was similar.
Go for it guy, when you get the brakes pulling right, they are good.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
|
|
|
|
|
|
| Re: [GMCnet] Brakes [message #310168 is a reply to message #310167] |
Wed, 09 November 2016 19:08 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
|
Senior Member |
|
|
ljdavick wrote on Wed, 09 November 2016 18:57My first thought is just what Jim K said - the rubber brake lines. Am I late to the thread - has this been fixed already?
Larry Davick
A Mystery Machine
1976(ish) Palm Beach
Fremont, CA
Howell EFI + EBL + Electronic Distributor
He stated that the rears were already replaced.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
|
|
|
|
|
|
| Re: Brakes [message #310213 is a reply to message #310188] |
Thu, 10 November 2016 16:34 |
C Boyd
Messages: 2629
Registered: April 2006
Karma: 18
|
Senior Member |
|
|
Somehow the 1 got dropped in my address book? Got er changed..
Nicholls wrote on Thu, 10 November 2016 10:07No sir, it is johnrita1@cox.net
C. Boyd
76 Crestmont
East Tennessee
|
|
|
|
| Re: Brakes [message #310446 is a reply to message #310045] |
Wed, 16 November 2016 20:36 |
Nicholls
Messages: 36
Registered: January 2008
Location: Pensacola, FL
Karma: 0
|
Member |
|
|
Progress Report
The pin is not too long. On to master cylinder replacement. Is there any way that the combination/proportioning valve could be involved with this problem?
FYI - The capture nut holding the upper bracket bolt spun. Believe it or not one can get vice grips behind the radio and grip it in order to get the bolt out. Takes two people. Fred made it happen.
John Nicholls,
78 Royale w/455
Pensacola, FL
|
|
|
|
Goto Forum:
Current Time: Fri Oct 04 03:30:33 CDT 2024
Total time taken to generate the page: 0.00938 seconds
|
GMCforum
Search
Help
Register
Login
Home
