Home » Public Forums » GMCnet » 80mm brake question
| 80mm brake question [message #115587] |
Fri, 18 February 2011 19:34  |
thorndike
Messages: 406
Registered: January 2011
Location: Conifer, Colorado
Karma: 0
|
Senior Member |
|
|
I have been going through the records of my new (to me) GMC and have not found evidence of the brakes being upgraded to the 80mm discs.
I hate to show my ignorance, but I am unsure how to tell if they have been upgraded. Does the 80mm refer to the radius of the disc? or length of the pad?, etc?
I promise, as I get smarter, the dumb questions will diminish..only to be replaced by equally dumb, but smarter sounding questions.
Robert Peesel
1976 Royale 26'
Side Dry Bath
Conifer, Colorado
|
|
|
|
|
|
| Re: 80mm brake question [message #115594 is a reply to message #115591] |
Fri, 18 February 2011 19:48  |
thorndike
Messages: 406
Registered: January 2011
Location: Conifer, Colorado
Karma: 0
|
Senior Member |
|
|
Yeah, I went from 80mm to 8cm and THOUGHT 8 inches. Which is why I thought about the radius of the disc.
So now I am even more confused.
Robert Peesel
1976 Royale 26'
Side Dry Bath
Conifer, Colorado
|
|
|
|
| Re: [GMCnet] 80mm brake question [message #115595 is a reply to message #115587] |
Fri, 18 February 2011 19:45 |
 |
USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
|
Senior Member |
|
|
Robert,
The 80mm refers to the OD of the caliper piston.
You can tell if your GMC has 80mm calipers by looking at the hose fittings
that connect to the calipers.
Here's a picture of 80mm calipers:
http://www.appliedgmc.com/prod.itml/icOid/949
Here's a picture of the lines that connect to them:
http://www.appliedgmc.com/prod.itml/icOid/951
Here's a picture of the standard caliper hoses:
http://www.appliedgmc.com/prod.itml/icOid/831
Note the "banjo" fitting on the end of the 80mm hoses vs. the straight
fitting on the end of the standard caliper hoses.
Regards,
Rob M.
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of Robert Peesel
Sent: Saturday, February 19, 2011 12:35 PM
To: gmclist@temp.gmcnet.org
Subject: [GMCnet] 80mm brake question
I have been going through the records of my new (to me) GMC and have not
found evidence of the brakes being upgraded to the 80mm discs.
I hate to show my ignorance, but I am unsure how to tell if they have been
upgraded. Does the 80mm refer to the radius of the disc? or length of the
pad?, etc?
I promise, as I get smarter, the dumb questions will diminish..only to be
replaced by equally dumb, but smarter sounding questions.
--
Robert Peesel
1976 Royale 26'
Side Dry Bath
Sterling, Va
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List 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: 80mm brake question [message #115596 is a reply to message #115587] |
Fri, 18 February 2011 19:53 |
Craig Lechowicz
Messages: 541
Registered: October 2006
Location: Waterford, MI
Karma: 0
|
Senior Member |
|
|
Robert,
80 mm. refers to the diameter of the piston that applies the pad to the rotor. The stock calipers are referred to as 70 mm. but someone on this site mentioned they are really 75mm. Probably the quickest way to tell them apart is by the hoses. The original hose has the rubber part essentially going right into the metal block that goes into the caliper. The 80 mm. calipers have maybe a 3" or so curved steel line between the end of the rubber and the part that goes on the caliper. May not be a very good description, but if you search the photo site, you can probably find some pictures.
Both calipers take the same pads.
Craig Lechowicz
'77 Kingsley, Waterford, MI
|
|
|
|
|
|
| Re: 80mm brake question [message #115598 is a reply to message #115587] |
Fri, 18 February 2011 19:55 |
C Boyd
Messages: 2629
Registered: April 2006
Karma: 18
|
Senior Member |
|
|
| thorndike wrote on Fri, 18 February 2011 20:34 |
I have been going through the records of my new (to me) GMC and have not found evidence of the brakes being upgraded to the 80mm discs.
I hate to show my ignorance, but I am unsure how to tell if they have been upgraded. Does the 80mm refer to the radius of the disc? or length of the pad?, etc?
I promise, as I get smarter, the dumb questions will diminish..only to be replaced by equally dumb, but smarter sounding questions.
|
just to look the difference is the fitting on the brake hose. The Caddy 80mm has a banjo looking fitting with a center bolt and the stock GMC has a threaded brake line fitting. I believe the 80mm is the contact area of the puck on the brake pad.
C. Boyd
76 Crestmont
East Tennessee
|
|
|
|
| Re: 80mm brake question [message #115599 is a reply to message #115596] |
Fri, 18 February 2011 19:55 |
Craig Lechowicz
Messages: 541
Registered: October 2006
Location: Waterford, MI
Karma: 0
|
Senior Member |
|
|
Rob,
Great minds think alike! You get bonus points for finding photo references. With the strong Ozzie dollar, the bonus points aren't worth much, though!
Craig Lechowicz
'77 Kingsley, Waterford, MI
|
|
|
|
|
|
|
|
| Re: 80mm brake question [message #115609 is a reply to message #115587] |
Fri, 18 February 2011 20:49 |
Craig Lechowicz
Messages: 541
Registered: October 2006
Location: Waterford, MI
Karma: 0
|
Senior Member |
|
|
Harry,
What an embarrassment that is! I'm in my 50's and I remember in grade school (1960's) they told us, the metric system was just around the corner. Then, when I worked for GM, all GM cars in 1980 were going to metric. Well, that was only for things designed new in or after 1980, and then only if they remembered to switch. Things like starters, alternators and other components didn't change for years. I'll bet you can still find a worm drive hose clamp on a 2011 vehicle that needs a 1/4" or 5/16" socket rather than a 7 or 10 mm. one. I guess it could still happen in my lifetime, but only if I start working out a lot more and eating a lot healthier. I forget the list, but I think we are only 1 of 3 countries that is non-metric. Mesopotamia may have been one of them. Please don't rub it in . . .
Craig Lechowicz
'77 Kingsley, Waterford, MI
|
|
|
|
| Re: [GMCnet] 80mm brake question [message #115610 is a reply to message #115596] |
Fri, 18 February 2011 20:54 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
|
Senior Member |
|
|
The 80mm uses Banjo fitting on the hose to the caliper.
On Fri, Feb 18, 2011 at 5:53 PM, Craig Lechowicz
<craig.lechowicz@sbcglobal.net> wrote:
>
>
> Robert,
> 80 mm. refers to the diameter of the piston that applies the pad to the rotor. The stock calipers are referred to as 70 mm. but someone on this site mentioned they are really 75mm. Probably the quickest way to tell them apart is by the hoses. The original hose has the rubber part essentially going right into the metal block that goes into the caliper. The 80 mm. calipers have maybe a 3" or so curved steel line between the end of the rubber and the part that goes on the caliper. May not be a very good description, but if you search the photo site, you can probably find some pictures.
>
> Both calipers take the same pads.
> --
> Craig Lechowicz
> '77 Kingsley, Waterford, MI
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List 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
Unsubscribe or Change List 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] 80mm brake question [message #115617 is a reply to message #115601] |
Fri, 18 February 2011 21:18 |
thorndike
Messages: 406
Registered: January 2011
Location: Conifer, Colorado
Karma: 0
|
Senior Member |
|
|
Thanks for the concern Tim,
I am only going to stick my head under to look. I am still looking for a location where I can jack this up for a few days to complete some longer jobs.
Bob
Robert Peesel
1976 Royale 26'
Side Dry Bath
Conifer, Colorado
|
|
|
|
| Re: 80mm brake question danger [message #115620 is a reply to message #115587] |
Fri, 18 February 2011 21:41 |
captjack
Messages: 271
Registered: February 2010
Location: Sebastopol, California
Karma: 1
|
Senior Member |
|
|
I second the thought about the dangers of crawling under the coach to look. It will be devastating to your pocketbook. First it's the calipers then, the steering gear looks like it's leaking and how come the air compressor is covered with gunk and aren't those cracks in the airbags so how about quadra-bags in the rear. It's happened to the best of us. Beware!
Jack Christensen - K6ROW,
'76 Glenbrook/Clasco - "The Silver Bullet",
Sebastopol, CA
|
|
|
|
| Re: [GMCnet] 80mm brake question [message #115621 is a reply to message #115587] |
Fri, 18 February 2011 21:41 |
powerjon
Messages: 2446
Registered: January 2004
Karma: 5
|
Senior Member |
|
|
Robert,
Here is how to do it.
http://www.gmcmotorhome.com/commodore/front_brake/index.html
JR Wright
On Feb 18, 2011, at 6:34 PM, Robert Peesel wrote:
>
>
> I have been going through the records of my new (to me) GMC and have not found evidence of the brakes being upgraded to the 80mm discs.
>
> I hate to show my ignorance, but I am unsure how to tell if they have been upgraded. Does the 80mm refer to the radius of the disc? or length of the pad?, etc?
>
> I promise, as I get smarter, the dumb questions will diminish..only to be replaced by equally dumb, but smarter sounding questions.
> --
> Robert Peesel
>
> 1976 Royale 26'
>
> Side Dry Bath
>
> Sterling, Va
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
J.R. Wright
GMC GreatLaker
GMC Eastern States
GMCMI
78 30' Buskirk Stretch
75 Avion Under Reconstruction
Michigan
|
|
|
|
| Re: [GMCnet] 80mm brake question [message #115624 is a reply to message #115617] |
Fri, 18 February 2011 21:48 |
Tim Conway
Messages: 412
Registered: September 2005
Location: Long Island, New York
Karma: 0
|
Senior Member |
|
|
On Feb 18, 2011, at 10:18 PM, Robert Peesel wrote:
> Thanks for the concern Tim,
>
> I am only going to stick my head under to look.
You're very welcome Bob. I've read here that when an airbag fails,
the coach drops so fast, you have no chance to get out first. The
odds of it failing at the time your head is under there may be slim,
but not worth any chance. People win the lottery with odds of a
million to one, things happen.
There are old threads out there like http://gmc.mybirdfeeder.net/
GMCforum/index.php?rid=0&t=msg&th=11263
and
http://gmc.mybirdfeeder.net/GMCforum/index.php?
t=msg&rid=0&th=13033&goto=93446
Tim Conway
LI NY 78 PB
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
|
|
|
|
|
|
| Re: [GMCnet] 80mm brake question [message #115666 is a reply to message #115601] |
Sat, 19 February 2011 08:14 |
 |
mike miller
Messages: 3576
Registered: February 2004
Location: Hillsboro, Oregon
Karma: 0
|
Senior Member |
|
|
| Tim Conway wrote on Fri, 18 February 2011 18:02 |
On Feb 18, 2011, at 8:54 PM, Robert Peesel wrote:
> I will crawl under the coach this weekend to see what I have.
Be careful, Robert. I've read much here regarding the danger of being
under a coach and how to be safe. I'm sure great advice will come up
here soon. Maybe you already are aware of it, but can't be too careful.
|
Sliding under the nose of the coach isn't much problem. It would take a torsion bar to snap or something to have an issue there. BUT I would just stay in front of the front tires.
Currently all my coach's boggie frames are resting on blocks. I can look under them all I please.... just to wet and cold.
Mike Miller -- Hillsboro, OR -- on the Black list
(#2)`78 23' Birchaven Rear Bath -- (#3)`77 23' Birchaven Side Bath
More Sidekicks than GMC's and a late model Malibu called 'Boo'
http://m000035.blogspot.com
|
|
|
|
Goto Forum:
Current Time: Mon Nov 18 16:44:32 CST 2024
Total time taken to generate the page: 0.01800 seconds
|
GMCforum
Search
Help
Register
Login
Home
