Home » Public Forums » GMCnet » [GMCnet] disk brake upgrade
| [GMCnet] disk brake upgrade [message #235135] |
Sun, 05 January 2014 09:59  |
glwgmc
Messages: 1014
Registered: June 2004
Karma: 10
|
Senior Member |
|
|
In all of these "bad" design choices keep in mind that the coaches were designed around bias ply tires which exhibit unique characteristics at speed which results in increased caster as speed increases. We now all run radial ply tires which do not, so we need to dial in more static caster to make up for that difference. When GM added the option for radial ply tires, bias ply tires were still also used on some coach versions so whatever they decided for static caster had to be a compromise. If they increased static caster for the radial ply tired coaches, it would increase the load on the steering components for the bias ply tired coaches. They apparently decided to leave the static caster spec at 2 degrees as that is where it stayed throughout the rest of production.
Rut wander became a real issue when in the 80s some suggested changing over to steel sidewall load range E radial ply tires run at 80 psi - supposedly for greater load carrying capacity in a condition when one front tire might carry higher than designed loads for a short period of time. With a fabric sidewall tires (load range D or E) set at the correct 55-65 PSI pressure for the loads our coach tires carry, rut wander even at lower caster angles speced for bias ply tires, is not too much of an issue if the rest of the front end components are tight.
Everything goes to hell in a hand bag when the front ride height is allowed to drop whether from age on the torsion bars, or because a PO thought it "looked better", or because the rear ride height adjusters are out of whack, or because a commercial alignment shop jacked up the front to make their adjustments and did not drive the coach to allow the front end to settle down to where it would be going down the road. Ride height low in front decreases whatever amount of caster we can get whether with the stock front end or with the one ton, and decreased caster will lead to the coach not wanting to drive straight no matter what else might be going on. Virtually all the coaches we measured coming into the GMCWS rally at Casa de Fruita, CA, a couple of years ago were ride height low in front - hence all came in with way too little caster for optimum cruise performance.
One final "interesting" note. This from the 1936 Cord publication, "Information for Salesmen" in the Questions and Answers section:
"Q - What is the width of the tread?
A - 56" front and 61" rear
Q - Why is the tread wider in the rear?
A - To allow more room in the body and to make the car wider and therefore safer, because it will not tip so easily"
Cord was a ground up design by Gordon Behrig as part of a design competition while he worked at GM. When he was hired to design a baby Duesenberg based on that design he was apparently under no constraints as to components from other vehicles that had to be used. He selected a wider rear track than front track for a front wheel drive car anyway. The car name was changed to Cord just before production commenced.
Jerry
Jerry Work
The Dovetail Joint
Fine furniture designed and hand crafted in the 1907 former Masonic Temple building in historic Kerby, OR
Visitors always welcome!
glwork@mac.com
http://jerrywork.com
=================
Message: 8
Date: Sat, 04 Jan 2014 16:51:25 -0600
From: Kerry Pinkerton <Pinkertonk@MCHSI.com>
Subject: Re: [GMCnet] disk brake upgrade
To: gmclist@temp.gmcnet.org
Message-ID: <3964a.52c8906c@gmc.mybirdfeeder.net>
Content-Type: text/plain; charset="ISO-8859-15"
snip+++++That said, I'd tend to think all of the items he mentioned are certainly not optimal. Imo, the front end, while it has indeed lasted for decades and works ok, is not a good design. The difference in track width was just cheaping out, same with the caster issues, all so they could use as much of the Toro clip as possible. Perhaps roads weren't as bad back then or perhaps a new coach didn't rut run like today.
I'd expect that by 1975, they knew about all these things that could be improved but didn't because they:
1- Didn't think the additional expenditures would increase revenue/profit
2- Bean counters (and I are one.. :) ) wouldn't let them spend the money.
Not slamming our coaches at all so I hope no one gets their knickers in a twist. I love my coach...and I love to try and make it better.
That said, If I can come across an extra set of bogies, I'm going to do two trailing arms on the Art Deco Car Hauler....and a 1 ton front end. With a blank slate chassis and no interior limitations, adding in the additional forward bogie mount and only using the trailing arms will be pretty straight forward++++snip.
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Jerry & Sharon Work
78 Royale
Kerby, OR
|
|
|
|
|
|
| Re: [GMCnet] disk brake upgrade [message #235223 is a reply to message #235206] |
Mon, 06 January 2014 08:41  |
Jim Bounds
Messages: 842
Registered: January 2004
Karma: 0
|
Senior Member |
|
|
I'm sure a selection of guys are going to roll back in their seats and go, "here we go again", I must tell you I have no troubles with rebuilding a brake system complete using drums in the back. The key is doing "everything". Don't try and diagnose a problem with your brakes, they are way too important a safety device to "guess" at problems especially on a 35+ year old machine. It's not the design of the system that has troubles-- it's a part in that system. My guess is if you still have an original combination valve it's clogged. Hey and don;t try and "rebuild" a throw away part, just get a new one and put it in! Now, I'm not telling you to just do that, there is NO 35+ year old part that should be in a critical system like your brakes. Come on man, you should not have that as a death wish! Any part of the brake system you have not replaced just get the parts and do it all. I will tell you when that is done, you will have good brakes
using the drum original system. You don;t need 80mm front calipers, bigger wheel cylinders or any of that. Bone stock I can slide 6 wheels going down the road!
If you wanna have a pile of that stuff go for it but you can get usable brakes with a complete original brake system restored to it's correct work. Like I said, there are differing views on this and yes, there have been improvements on brakes in the last 30 years --- but-- GM did not put out a defective, non useable system in the first place and any changes you do you your DOT approved safety device brake system and YOU will be backing the liability yourself if something goes terribly wrong. I am NOT an engineer so I will defer to the guy that did the original data. It works and if you don;t want to change things, you do not have to.
Oh crap, guess I just opened the flood doors, I have my water wings on...
Jim Bounds
------------------------
On Monday, January 6, 2014 7:16 AM, gmccoop <gmccoop@yahoo.com> wrote:
Have tried to trace down some recent spews abot brake boosters and vacuum resevours. There are several really dumb statements I really feel needs cleaning up.
1. Senarized brake boosters do not leak. If a booster goes bad yes but they do not leak as part of their nnormal operation. I have had a few fail hut it would be incorrect to say they leak, who would say something like that?
2. I have run on my coach for years and installed a PVC constrhcted vaccum brake resevour system on man tv coaches. They give you reliably 5-6 hits on your brakes to allow you to pull oover under power safely. It woorks perfect. To be honest, I cannot see why anyone would put the highest failure rate electrical components ( relays and motors) to make up a safety device! Since when are high maintenance devices more reliable than a tank and 1 check valve.
I feel there are misinformed people running ammuck here. Whats going on?
Jim Bounds
Have tried to trace down some recent spews abot brake boosters and vacuum resevours. There are several really dumb statements I really feel needs cleaning up.
1. Senarized brake boosters do not leak. If a booster goes bad yes but they do not leak as part of their nnormal operation. I have had a few fail hut it would be incorrect to say they leak, who would say something like that?
2. I have run on my coach for years and installed a PVC constrhcted vaccum brake resevour system on man tv coaches. They give you reliably 5-6 hits on your brakes to allow you to pull oover under power safely. It woorks perfect. To be honest, I cannot see why anyone would put the highest failure rate electrical components ( relays and motors) to make up a safety device! Since when are high maintenance devices more reliable than a tank and 1 check valve.
I feel there are misinformed people running ammuck here. Whats going on?
Jim Bounds
-------- Original message --------
From: Bob de Kruyff <NEXT2POOL@AOL.COM>
Date: 01/04/2014 8:08 PM (GMT-05:00)
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] disk brake upgrade
""I think you misread or misunderstood what Keith wrote. He was referring to in his experience in engineering, there were some amazingly bad designs out there....not specifically referring to the GMC. At least that is how I read it.::
The bad designs out here are the arm chair wannabee engineers that feel compelled to modify our coaches. A great example is the sensitized booster that leaks vacuum--how wonderfull is that?
--
Bob de Kruyff
78 Eleganza
Chandler, AZ
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
""I think you misread or misunderstood what Keith wrote. He was referring to in his experience in engineering, there were some amazingly bad designs out there....not specifically referring to the GMC. At least that is how I read it.::
The bad designs out here are the arm chair wannabee engineers that feel compelled to modify our coaches. A great example is the sensitized booster that leaks vacuum--how wonderfull is that?
--
Bob de Kruyff
78 Eleganza
Chandler, AZ
_______________________________________________
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
|
|
|
|
| Re: [GMCnet] disk brake upgrade [message #235230 is a reply to message #235223] |
Mon, 06 January 2014 09:26 |
Les
Messages: 29
Registered: March 2009
Location: Meredith NH
Karma: 0
|
Junior Member |
|
|
Hi Jim
I agree with you up to a point, i have ALL original shoes, pads, cyl's, etc, and i was able to lock,em up years ago, i have what a would consider good brakes NOT great breaks, i can stop fine, but can not drag the rears, every thing has been replaced within the last 5 years, except the booster, hell, you did most of it, i've owned this coach over 28 years, the old asbestos shoes and pads were far superior to this new stuff, i wonder if the engineers at GMC would have done something different if they had to deal with it, years ago ARCH was working on this problem, i believe he had pads imported,( yellow stuff, green stuff ) do you know if these are available ?
Les Simpson
76 Glenbrook
Meredith, NH
> Date: Mon, 6 Jan 2014 06:41:39 -0800
> From: gmccoop@yahoo.com
> To: gmclist@temp.gmcnet.org
> Subject: Re: [GMCnet] disk brake upgrade
>
> I'm sure a selection of guys are going to roll back in their seats and go, "here we go again", I must tell you I have no troubles with rebuilding a brake system complete using drums in the back. The key is doing "everything". Don't try and diagnose a problem with your brakes, they are way too important a safety device to "guess" at problems especially on a 35+ year old machine. It's not the design of the system that has troubles-- it's a part in that system. My guess is if you still have an original combination valve it's clogged. Hey and don;t try and "rebuild" a throw away part, just get a new one and put it in! Now, I'm not telling you to just do that, there is NO 35+ year old part that should be in a critical system like your brakes. Come on man, you should not have that as a death wish! Any part of the brake system you have not replaced just get the parts and do it all. I will tell you when that is done, you will have good brakes
> using the drum original system. You don;t need 80mm front calipers, bigger wheel cylinders or any of that. Bone stock I can slide 6 wheels going down the road!
>
> If you wanna have a pile of that stuff go for it but you can get usable brakes with a complete original brake system restored to it's correct work. Like I said, there are differing views on this and yes, there have been improvements on brakes in the last 30 years --- but-- GM did not put out a defective, non useable system in the first place and any changes you do you your DOT approved safety device brake system and YOU will be backing the liability yourself if something goes terribly wrong. I am NOT an engineer so I will defer to the guy that did the original data. It works and if you don;t want to change things, you do not have to.
>
> Oh crap, guess I just opened the flood doors, I have my water wings on...
>
> Jim Bounds
> ------------------------
>
>
>
> On Monday, January 6, 2014 7:16 AM, gmccoop <gmccoop@yahoo.com> wrote:
>
> Have tried to trace down some recent spews abot brake boosters and vacuum resevours. There are several really dumb statements I really feel needs cleaning up.
>
> 1. Senarized brake boosters do not leak. If a booster goes bad yes but they do not leak as part of their nnormal operation. I have had a few fail hut it would be incorrect to say they leak, who would say something like that?
>
> 2. I have run on my coach for years and installed a PVC constrhcted vaccum brake resevour system on man tv coaches. They give you reliably 5-6 hits on your brakes to allow you to pull oover under power safely. It woorks perfect. To be honest, I cannot see why anyone would put the highest failure rate electrical components ( relays and motors) to make up a safety device! Since when are high maintenance devices more reliable than a tank and 1 check valve.
>
> I feel there are misinformed people running ammuck here. Whats going on?
>
> Jim Bounds
> Have tried to trace down some recent spews abot brake boosters and vacuum resevours. There are several really dumb statements I really feel needs cleaning up.
>
> 1. Senarized brake boosters do not leak. If a booster goes bad yes but they do not leak as part of their nnormal operation. I have had a few fail hut it would be incorrect to say they leak, who would say something like that?
>
> 2. I have run on my coach for years and installed a PVC constrhcted vaccum brake resevour system on man tv coaches. They give you reliably 5-6 hits on your brakes to allow you to pull oover under power safely. It woorks perfect. To be honest, I cannot see why anyone would put the highest failure rate electrical components ( relays and motors) to make up a safety device! Since when are high maintenance devices more reliable than a tank and 1 check valve.
>
> I feel there are misinformed people running ammuck here. Whats going on?
>
> Jim Bounds
>
>
> -------- Original message --------
> From: Bob de Kruyff <NEXT2POOL@AOL.COM>
> Date: 01/04/2014 8:08 PM (GMT-05:00)
> To: gmclist@temp.gmcnet.org
> Subject: Re: [GMCnet] disk brake upgrade
>
>
>
>
>
> ""I think you misread or misunderstood what Keith wrote. He was referring to in his experience in engineering, there were some amazingly bad designs out there....not specifically referring to the GMC. At least that is how I read it.::
>
> The bad designs out here are the arm chair wannabee engineers that feel compelled to modify our coaches. A great example is the sensitized booster that leaks vacuum--how wonderfull is that?
> --
> Bob de Kruyff
> 78 Eleganza
> Chandler, AZ
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
>
>
> ""I think you misread or misunderstood what Keith wrote. He was referring to in his experience in engineering, there were some amazingly bad designs out there....not specifically referring to the GMC. At least that is how I read it.::
>
> The bad designs out here are the arm chair wannabee engineers that feel compelled to modify our coaches. A great example is the sensitized booster that leaks vacuum--how wonderfull is that?
> --
> Bob de Kruyff
> 78 Eleganza
> Chandler, AZ
> _______________________________________________
> 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
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Les & Sue Simpson
Meredith, NH
1976 X-Glenbrook
2000 Heritage Softail
|
|
|
|
| Re: [GMCnet] disk brake upgrade [message #235294 is a reply to message #235135] |
Mon, 06 January 2014 17:12 |
Jim Bounds
Messages: 842
Registered: January 2004
Karma: 0
|
Senior Member |
|
|
Yea, Arch was the one who brought in the yellow pads to the community. Â Yea I know the early shoes were better but I will tell you I can skid 6 wheels with a fresh rebuild. Â Did you change the combo valve.
Here's the thing, folks find their brakes are not good and figure its a bad system.  You shoould first give the system a chance and totally renew the system before you say you need more.  I just feel before you  do that, you are not being fair.
There has to dialog from both sides before you have input and make an informed decision. Â That is only right,Â
Jim Bounds
-------- Original message --------
From: Lester Simpson <lesfromnh@live.com>
Date: 01/06/2014 10:26 AM (GMT-05:00)
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] disk brake upgrade
Hi Jim
  I agree with you up to a point, i have ALL original shoes, pads, cyl's, etc, and i was able to lock,em up years ago, i have what a would consider good brakes NOT great breaks, i can stop fine, but can not drag the rears, every thing has been replaced within the last 5 years, except the booster, hell, you did most of it, i've owned this coach over 28 years, the old asbestos shoes and pads were far superior to this new stuff, i wonder if the engineers at GMC would have done something different if they had to deal with it, years ago ARCH was working on this problem, i believe he had pads imported,( yellow stuff, green stuff ) do you know if these are available ?
Les Simpson
76 Glenbrook
Meredith, NH
> Date: Mon, 6 Jan 2014 06:41:39 -0800
> From: gmccoop@yahoo.com
> To: gmclist@temp.gmcnet.org
> Subject: Re: [GMCnet] disk brake upgrade
>
> I'm sure a selection of guys are going to roll back in their seats and go, "here we go again", I must tell you I have no troubles with rebuilding a brake system complete using drums in the back. The key is doing "everything". Don't try and diagnose a problem with your brakes, they are way too important a safety device to "guess" at problems especially on a 35+ year old machine. It's not the design of the system that has troubles-- it's a part in that system. My guess is if you still have an original combination valve it's clogged. Hey and don;t try and "rebuild" a throw away part, just get a new one and put it in! Now, I'm not telling you to just do that, there is NO 35+ year old part that should be in a critical system like your brakes. Come on man, you should not have that as a death wish! Any part of the brake system you have not replaced just get the parts and do it all. I will tell you when that is done, you will have good brakes
> using the drum original system. You don;t need 80mm front calipers, bigger wheel cylinders or any of that. Bone stock I can slide 6 wheels going down the road!
>Â
> If you wanna have a pile of that stuff go for it but you can get usable brakes with a complete original brake system restored to it's correct work. Like I said, there are differing views on this and yes, there have been improvements on brakes in the last 30 years --- but-- GM did not put out a defective, non useable system in the first place and any changes you do you your DOT approved safety device brake system and YOU will be backing the liability yourself if something goes terribly wrong. I am NOT an engineer so I will defer to the guy that did the original data. It works and if you don;t want to change things, you do not have to.
>Â
> Oh crap, guess I just opened the flood doors, I have my water wings on...
>Â
> Jim Bounds
> ------------------------
>
>
>
> On Monday, January 6, 2014 7:16 AM, gmccoop <gmccoop@yahoo.com> wrote:
>Â Â
> Have tried to trace down some recent spews abot brake boosters and vacuum resevours. There are several really dumb statements I really feel needs cleaning up.
>
> 1. Senarized brake boosters do not leak. If a booster goes bad yes but they do not leak as part of their nnormal operation. I have had a few fail hut it would be incorrect to say they leak, who would say something like that?
>
> 2. I have run on my coach for years and installed a PVC constrhcted vaccum brake resevour system on man tv coaches. They give you reliably 5-6 hits on your brakes to allow you to pull oover under power safely. It woorks perfect. To be honest, I cannot see why anyone would put the highest failure rate electrical components ( relays and motors) to make up a safety device! Since when are high maintenance devices more reliable than a tank and 1 check valve.
>
> I feel there are misinformed people running ammuck here. Whats going on?
>
> Jim Bounds
> Have tried to trace down some recent spews abot brake boosters and vacuum resevours. There are several really dumb statements I really feel needs cleaning up.
>
> 1. Senarized brake boosters do not leak. If a booster goes bad yes but they do not leak as part of their nnormal operation. I have had a few fail hut it would be incorrect to say they leak, who would say something like that?
>
> 2. I have run on my coach for years and installed a PVC constrhcted vaccum brake resevour system on man tv coaches. They give you reliably 5-6 hits on your brakes to allow you to pull oover under power safely. It woorks perfect. To be honest, I cannot see why anyone would put the highest failure rate electrical components ( relays and motors) to make up a safety device! Since when are high maintenance devices more reliable than a tank and 1 check valve.
>
> I feel there are misinformed people running ammuck here. Whats going on?
>
> Jim Bounds
>
>
> -------- Original message --------
> From: Bob de Kruyff <NEXT2POOL@AOL.COM>
> Date: 01/04/2014Â 8:08 PMÂ (GMT-05:00)
> To: gmclist@temp.gmcnet.org
> Subject: Re: [GMCnet] disk brake upgrade
>
>
>
>
>
> ""I think you misread or misunderstood what Keith wrote. He was referring to in his experience in engineering, there were some amazingly bad designs out there....not specifically referring to the GMC. At least that is how I read it.::
>
> The bad designs out here are the arm chair wannabee engineers that feel compelled to modify our coaches. A great example is the sensitized booster that leaks vacuum--how wonderfull is that?
> --
> Bob de Kruyff
> 78 Eleganza
> Chandler, AZ
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
>
>
> ""I think you misread or misunderstood what Keith wrote. He was referring to in his experience in engineering, there were some amazingly bad designs out there....not specifically referring to the GMC. At least that is how I read it.::
>
> The bad designs out here are the arm chair wannabee engineers that feel compelled to modify our coaches. A great example is the sensitized booster that leaks vacuum--how wonderfull is that?
> --
> Bob de Kruyff
> 78 Eleganza
> Chandler, AZ
> _______________________________________________
> 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
  Â
_______________________________________________
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
|
|
|
|
| Re: [GMCnet] disk brake upgrade [message #235307 is a reply to message #235294] |
Mon, 06 January 2014 20:24 |
Neil
Messages: 271
Registered: July 2007
Location: Los Angeles and Magalia, ...
Karma: 1
|
Senior Member |
|
|
On the subject of brakes, I just want to say that I have a stock system with the infamous yellow pads up front, lovingly maintained by Miguel and it all stops just fine. It stops even better with a big 20 foot trailer loaded to the gills and electric trailer brakes, and it stops just fine with a towd with a Unified Braking system.
Six wheel disc brakes and reaction arms may be infinitely better, but now that I have everything working, I have no complaints.
YMMV
Neil
76 Eleganza now sold
Los Angeles
|
|
|
|
| Re: [GMCnet] disk brake upgrade [message #235311 is a reply to message #235135] |
Mon, 06 January 2014 20:41 |
 |
SeanKidd
Messages: 747
Registered: June 2012
Location: Northern Neck Virginia
Karma: 4
|
Senior Member |
|
|
I agree, 6 wheel disc, 90mm up front, Jim K / rear kit with reaction arms and quad bag, only my MINI Cooper S stops better.
Sean and Stephanie
73 Ex-CanyonLands 26' #317 "Oliver"
Hubler 1-Ton, Quad-Bags, Rear Disc, Reaction Arms, P.Huber TBs, 3.70:1 LSD Honda 6500 inverter gen.
Colonial Travelers
|
|
|
|
| Re: [GMCnet] disk brake upgrade [message #235317 is a reply to message #235311] |
Mon, 06 January 2014 22:15 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
|
Senior Member |
|
|
Les, Why don't you go to our web site.
We have the most complete lineup of pads like the Yellow Pad by EBC. Our
prices are better than summits.
Our rear dice brakes are of Cad type so you'll stop belter than the others.
On Mon, Jan 6, 2014 at 6:41 PM, Sean Kidd <fiatkidd@yahoo.com> wrote:
>
>
> I agree, 6 wheel disc, 90mm up front, Jim K / rear kit with reaction arms
> and quad bag, only my MINI Cooper S stops better.
> --
> Sean and Stephanie
> 73 Ex-CanyonLands 26' #317 "Oliver"
> Hubler 1-Ton, Quad-Bags, Rear Disc, Reaction Arms,
> Fluorescent Mineral Capital of the World, New Jersey
> _______________________________________________
> 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] disk brake upgrade [message #235345 is a reply to message #235206] |
Tue, 07 January 2014 07:52 |
jhbridges
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
|
Senior Member |
|
|
1. True dat. If it leaks, it's busted.
2. Proper installation of a vacuum pump will decrease reliability by 1 check valve. The failure rate of these valves is very low. The return for this risk is reliable braking for as long as the battery holds out. This is a reasonable risk.reward ratio for installing the pump.
I'll note that, while normally moving parts sghow the higher failure rate than non-moving, among electronic stuff the highest failure over the last five to seven years has been electolytic capacitors. The reason for this is involved, I'll 'splain it if anyone is interested.
--johnny
'76 23' transmode norris
'76 palm beach
From: gmccoop <gmccoop@yahoo.com>
To: gmclist@temp.gmcnet.org
Sent: Monday, January 6, 2014 7:16 AM
Subject: Re: [GMCnet] disk brake upgrade
Have tried to trace down some recent spews abot brake boosters and vacuum resevours. There are several really dumb statements I really feel needs cleaning up.
1. Senarized brake boosters do not leak. If a booster goes bad yes but they do not leak as part of their nnormal operation. I have had a few fail hut it would be incorrect to say they leak, who would say something like that?
2. I have run on my coach for years and installed a PVC constrhcted vaccum brake resevour system on man tv coaches. They give you reliably 5-6 hits on your brakes to allow you to pull oover under power safely. It woorks perfect. To be honest, I cannot see why anyone would put the highest failure rate electrical components ( relays and motors) to make up a safety device! Since when are high maintenance devices more reliable than a tank and 1 check valve.
I feel there are misinformed people running ammuck here. Whats going on?
Jim Bounds
-------- Original message --------
From: Bob de Kruyff <NEXT2POOL@AOL.COM>
Date: 01/04/2014 8:08 PM (GMT-05:00)
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] disk brake upgrade
""I think you misread or misunderstood what Keith wrote. He was referring to in his experience in engineering, there were some amazingly bad designs out there....not specifically referring to the GMC. At least that is how I read it.::
The bad designs out here are the arm chair wannabee engineers that feel compelled to modify our coaches. A great example is the sensitized booster that leaks vacuum--how wonderfull is that?
--
Bob de Kruyff
78 Eleganza
Chandler, AZ
_______________________________________________
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
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
|
|
|
|
|
|
| Re: [GMCnet] disk brake upgrade [message #235371 is a reply to message #235353] |
Tue, 07 January 2014 12:22 |
jhbridges
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
|
Senior Member |
|
|
Also not as great as electrolytics currently. Plus, they're fixable. My Collins designed transmitters' design first saw daylight in 1968. I have to clean (not replace) the occasional relay on the order of about one a year - I run 6 of them currently. I expect this to change, the Elves in Dallas told me there's a redesign of that part of the radio coming, because P&B no longer manufacture that particular relay.
Now, as to the new style AC relays which split the coil and stick a diode in, all bets are off. They >will;< fail fairly often. The copper slugged ones won't. But, diodes are way cheaper than copper these days. I'll stick to DC relays where I can.
--johnny
From: Larry <weidnerl@wwt.net>
To: gmclist@temp.gmcnet.org
Sent: Tuesday, January 7, 2014 9:54 AM
Subject: Re: [GMCnet] disk brake upgrade
Johnny Bridges wrote on Tue, 07 January 2014 07:52
> 1. True dat. If it leaks, it's busted.
> 2. Proper installation of a vacuum pump will decrease reliability by 1 check valve. The failure rate of these valves is very low. The return for this risk is reliable braking for as long as the battery holds out. This is a reasonable risk.reward ratio for installing the pump.
>
> I'll note that, while normally moving parts sghow the higher failure rate than non-moving, among electronic stuff the highest failure over the last five to seven years has been electolytic capacitors. The reason for this is involved, I'll 'splain it if anyone is interested.
>
> --johnny
> '76 23' transmode norris
> '76 palm beach
How about failure rate of relays?
--
Larry :)
78 Royale w/500 Caddy
Menomonie, WI.
_______________________________________________
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
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
|
|
|
|
Goto Forum:
Current Time: Sat Oct 05 13:20:55 CDT 2024
Total time taken to generate the page: 0.00778 seconds
|
GMCforum
Search
Help
Register
Login
Home
