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[GMCnet] Booster Replacement [message #326072] Thu, 16 November 2017 11:12 Go to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
G'day,

I am going to be replacing the booster in the Kingsley with one of Dave Lenzi's sensitized boosters. I vaguely remember reading
something about it being a PITA on a coach that does not have the PowerLevel system as the access to the nuts on the cockpit side of
the firewall are impossible to reach. I also remember someone noting that they cut a BIG hole in the lower part of the dashboard to
make the access easier. Can anyone provide any info about where to cut the hole, how big to make the hole, and the tool used to cut
the hole. A photo would be most helpful.

Regards,
Rob M.
The Pedantic Mechanic
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808
 



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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] Booster Replacement [message #326073 is a reply to message #326072] Thu, 16 November 2017 11:45 Go to previous messageGo to next message
powerjon is currently offline  powerjon   United States
Messages: 2446
Registered: January 2004
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Senior Member
Rob,
See the following:

http://www.gmcmhphotos.com/photos/bob-dunahugh/p60045-brake-booster-nuts-in-2777-and-2778-gmcs.html

http://www.gmcmhphotos.com/photos/bob-dunahugh/p60044-brake-booster-nuts-in-2777-and-2778-gmcs.html

JR

> On Nov 16, 2017, at 12:12 PM, Rob Mueller wrote:
>
> G'day,
>
> I am going to be replacing the booster in the Kingsley with one of Dave Lenzi's sensitized boosters. I vaguely remember reading
> something about it being a PITA on a coach that does not have the PowerLevel system as the access to the nuts on the cockpit side of
> the firewall are impossible to reach. I also remember someone noting that they cut a BIG hole in the lower part of the dashboard to
> make the access easier. Can anyone provide any info about where to cut the hole, how big to make the hole, and the tool used to cut
> the hole. A photo would be most helpful.
>
> Regards,
> Rob M.
> The Pedantic Mechanic
> Sydney, Australia
> AUS '75 Avion - The Blue Streak TZE365V100428
> USA '75 Avion - Double Trouble TZE365V100426
> USA '77 Kingsley - TZE 267V100808
>
>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org


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J.R. Wright
GMC GreatLaker
GMC Eastern States
GMCMI
78 30' Buskirk Stretch
75 Avion Under Reconstruction
Michigan
Re: [GMCnet] Booster Replacement [message #326074 is a reply to message #326073] Thu, 16 November 2017 12:18 Go to previous messageGo to next message
k2gkk is currently offline  k2gkk   United States
Messages: 4452
Registered: November 2009
Karma: -8
Senior Member
That is pretty much the same method my neighbor mechanic used to install my Lenzi brake booster a few weeks ago.

D C "Mac" Macdonald
Amateur Radio K2GKK
Since 30 November '53
USAF and FAA, Retired
Member GMCMI & Classics
Oklahoma City, OK
"The Money Pit"
TZE166V101966
'76 ex-Palm Beach
k2gkk + hotmail dot com


________________________________
From: Gmclist on behalf of John Wright
Sent: Thursday, November 16, 2017 11:45
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] Booster Replacement

Rob,
See the following:

https://nam03.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.gmcmhphotos.com%2Fphotos%2Fbob-dunahugh%2Fp60045-brake-booster-nuts-in-2777-and-2 778-gmcs.html&data=02%7C01%7Ck2gkk%40hotmail.com%7C8d791e367b734d9ae74208d52d19f97c%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C63646451193406839 2&sdata=2%2BVyz1XaNuXPvhGu4tSyvzh8wtiz%2BP0J7GehTDYr6OE%3D&reserved=0

https://nam03.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.gmcmhphotos.com%2Fphotos%2Fbob-dunahugh%2Fp60044-brake-booster-nuts-in-2777-and-2 778-gmcs.html&data=02%7C01%7Ck2gkk%40hotmail.com%7C8d791e367b734d9ae74208d52d19f97c%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C63646451193406839 2&sdata=o50wyu3kRzakU8d8gWq6kauJYFcXo4iW3txVxxf2nSU%3D&reserved=0

JR

> On Nov 16, 2017, at 12:12 PM, Rob Mueller wrote:
>
> G'day,
>
> I am going to be replacing the booster in the Kingsley with one of Dave Lenzi's sensitized boosters. I vaguely remember reading
> something about it being a PITA on a coach that does not have the PowerLevel system as the access to the nuts on the cockpit side of
> the firewall are impossible to reach. I also remember someone noting that they cut a BIG hole in the lower part of the dashboard to
> make the access easier. Can anyone provide any info about where to cut the hole, how big to make the hole, and the tool used to cut
> the hole. A photo would be most helpful.
>
> Regards,
> Rob M.
> The Pedantic Mechanic
> Sydney, Australia
> AUS '75 Avion - The Blue Streak TZE365V100428
> USA '75 Avion - Double Trouble TZE365V100426
> USA '77 Kingsley - TZE 267V100808
>
>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> https://nam03.safelinks.protection.outlook.com/?url=http%3A%2F%2Flist.gmcnet.org%2Fmailman%2Flistinfo%2Fgmclist_list.gmcnet.org&data=02%7C01%7Ck2g kk%40hotmail.com%7C8d791e367b734d9ae74208d52d19f97c%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636464511934068392&sdata=ktAJElWB2Jfoh26fDR17XZFD Rsuz%2F7wAArBbtVby%2BCg%3D&reserved=0


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Re: [GMCnet] Booster Replacement [message #326080 is a reply to message #326072] Thu, 16 November 2017 14:21 Go to previous messageGo to next message
RF_Burns is currently offline  RF_Burns   Canada
Messages: 2276
Registered: June 2008
Location: S. Ontario, Canada
Karma: 3
Senior Member
The top nut on the passenger side requires the use of a wide range of cuss words, especially getting the washers back in place and the nut started on the threads.

Anyone know if the bracket on the master cylinder is even required? I've never seen one on any other vehicle.


Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.
1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that
Re: [GMCnet] Booster Replacement [message #326081 is a reply to message #326072] Thu, 16 November 2017 14:36 Go to previous messageGo to next message
Scott Nutter is currently offline  Scott Nutter   United States
Messages: 781
Registered: January 2015
Location: Houston/San Diego
Karma: 4
Senior Member
Rob,
I put one of Daves in 6 months ago.
I can come by and help you if you would like.
Scott.


Scott Nutter 1978 Royale Center Kitchen, Patterson 455, switch pitch tranny, 3.21 final drive, Quad bags, Dave Lenzi super duty mid axle disc brakes, tankless water heater, everything Lenzi. Alex Ferrera installed MSD Atomic EFI Houston, Texas
Re: [GMCnet] Booster Replacement [message #326082 is a reply to message #326072] Thu, 16 November 2017 15:14 Go to previous messageGo to next message
lqqkatjon is currently offline  lqqkatjon   United States
Messages: 2324
Registered: October 2010
Location: St. Cloud, MN
Karma: 5
Senior Member
Some dashes can be flexed, and the correct small hands can get those nuts without cutting.

A thin ratchet wrench is needed. I use a craftsman ratchet wrench.



Jon Roche 75 palm beach EBL EFI, manny headers, Micro Level, rebuilt most of coach now. St. Cloud, MN http://lqqkatjon.blogspot.com/
Re: [GMCnet] Booster Replacement [message #326083 is a reply to message #326082] Thu, 16 November 2017 15:42 Go to previous messageGo to next message
Ken Burton is currently offline  Ken Burton   United States
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
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Senior Member
lqqkatjon wrote on Thu, 16 November 2017 15:14
Some dashes can be flexed, and the correct small hands can get those nuts without cutting.

A thin ratchet wrench is needed. I use a craftsman ratchet wrench.


I replaced mine quite a few years ado WITHOUT cutting a hole. It was a lot of fun getting in there with just about every small wrench I own but it is possible. I am NOT PowerLevel. Mine is Electro level I


Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
Re: [GMCnet] Booster Replacement [message #326084 is a reply to message #326080] Thu, 16 November 2017 15:45 Go to previous messageGo to next message
emerystora is currently offline  emerystora   United States
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Senior Member
Yes, you definitely need the brace. Otherwise you eventually will stress crack the metal where the booster is mounted.

Emery Stora

> On Nov 16, 2017, at 1:21 PM, Bruce Hislop wrote:
>
> The top nut on the passenger side requires the use of a wide range of cuss words, especially getting the washers back in place and the nut started on
> the threads.
>
> Anyone know if the bracket on the master cylinder is even required? I've never seen one on any other vehicle.
> --
> Bruce Hislop
> ON Canada
> 77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.
> Hubler 1 ton front end
> http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
> My Staff says I never listen to them, or something like that
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

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Re: [GMCnet] Booster Replacement [message #326086 is a reply to message #326083] Thu, 16 November 2017 19:11 Go to previous messageGo to next message
Rollerg is currently offline  Rollerg   United States
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Registered: November 2014
Location: Marysville, MI
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Senior Member
I know that I had success using a racheting box end wrench and a lot of patience.
I was able to get at from the side and flexing the dash .
Dave’s sensitized booster has been a big plus for our coach. Especially with mountain driving ing the west.

Gary Coaster / Reno, NV
1977 GMC Eleganza ll
GMC RV Day Night Shade Sales
GMCShades@gmail.com
www.GMCMotorhomemarketplace.com/GMC_Shades/

> On Nov 16, 2017, at 1:42 PM, Ken Burton wrote:
>
> lqqkatjon wrote on Thu, 16 November 2017 15:14
>> Some dashes can be flexed, and the correct small hands can get those nuts without cutting.
>>
>> A thin ratchet wrench is needed. I use a craftsman ratchet wrench.
>
> I replaced mine quite a few years ado WITHOUT cutting a hole. It was a lot of fun getting in there with just about every small wrench I own but it is
> possible. I am NOT PowerLevel. Mine is Electro level I
> --
> Ken Burton - N9KB
> 76 Palm Beach
> Hebron, Indiana
>
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Re: [GMCnet] Booster Replacement [message #326088 is a reply to message #326086] Thu, 16 November 2017 19:25 Go to previous messageGo to next message
Ken Henderson is currently offline  Ken Henderson   United States
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
Senior Member
I haven't had to do that job on a 77+, but, I'd guess that if that
ratcheting box end were one of those with the "broken back", it would make
the task a lot easier -- you can get into 'most anywhere with those.

Ken H.


On Thu, Nov 16, 2017 at 8:11 PM, Gary wrote:

> I know that I had success using a racheting box end wrench and a lot of
> patience.
> I was able to get at from the side and flexing the dash .
> Dave’s sensitized booster has been a big plus for our coach. Especially
> with mountain driving in the west.
>
​...​
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
Re: [GMCnet] Booster Replacement [message #326089 is a reply to message #326088] Thu, 16 November 2017 19:47 Go to previous messageGo to next message
James Hupy is currently offline  James Hupy   United States
Messages: 6806
Registered: May 2010
Karma: -62
Senior Member
Early coaches with the air knobs in the dash, can be accessed by removing
that panel. Later coaches with the rocker switches to the left side of the
drivers left elbow can be accessed by removing the heater control assembly.
I usually drill a 2" hole in the lower dash with a hole saw in line with
the lower left nut, and reach in with a socket and long extension. Assembly
, I use sticky body sealant (dum dum) putty to stick the nut to the socket.
Jim Hupy

On Nov 16, 2017 5:26 PM, "Ken Henderson" wrote:

> I haven't had to do that job on a 77+, but, I'd guess that if that
> ratcheting box end were one of those with the "broken back", it would make
> the task a lot easier -- you can get into 'most anywhere with those.
>
> Ken H.
>
>
> On Thu, Nov 16, 2017 at 8:11 PM, Gary wrote:
>
>> I know that I had success using a racheting box end wrench and a lot of
>> patience.
>> I was able to get at from the side and flexing the dash .
>> Dave’s sensitized booster has been a big plus for our coach. Especially
>> with mountain driving in the west.
>>
> ​...​
> _______________________________________________
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> Unsubscribe or Change List Options:
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>
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Re: [GMCnet] Booster Replacement [message #326093 is a reply to message #326072] Thu, 16 November 2017 20:40 Go to previous messageGo to next message
Jerry Sitzlar is currently offline  Jerry Sitzlar   United States
Messages: 206
Registered: February 2013
Location: Lenoir City, TN
Karma: 4
Senior Member
Rob,

I replaced the booster on my 77 Eleganza this past summer. I did not make any cuts to the outside of the dash, only a very small cut underneath where it is not visible. It was easy peasy. Tomorrow I'll try to take pics.

Jerry


Jerry Sitzlar..... 77 Eleganza II, Twin bed, dry bath...... Lenoir City, TN (near Knoxville)
Re: [GMCnet] Booster Replacement [message #326138 is a reply to message #326093] Sat, 18 November 2017 08:25 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
G'day,

Thanks guys!

Regards,
Rob M.
The Pedantic Mechanic
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808



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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] Booster Replacement [message #326139 is a reply to message #326084] Sat, 18 November 2017 08:37 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Emery,

Spot on!

When the M/C in Double Trouble started "playing up" I had Helen push on the brakes with the engine running to see what was going on.


I watched the M/C to see where it was leaking and was surprised to see the booster moving when she pushed the pedal. The brace was
installed; however, the rivnuts in the dash had come out and someone used lag bolts to hold it to the bottom of the dash!

I got some steel rivnuts that look like Molly bolts from McMaster-Carr and installed them in the bottom of the dash. I used epoxy on
them to make sure they wouldn't turn when the bracket retaining bolts were installed.

That was back in 2008 and so far so good.

Regards,
Rob M.
The Pedantic Mechanic
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808



-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of Emery Stora
Sent: Thursday, November 16, 2017 3:46 PM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] Booster Replacement

Yes, you definitely need the brace. Otherwise you eventually will stress crack the metal where the booster is mounted.

Emery Stora



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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] Booster Replacement [message #326141 is a reply to message #326084] Sat, 18 November 2017 09:30 Go to previous message
RF_Burns is currently offline  RF_Burns   Canada
Messages: 2276
Registered: June 2008
Location: S. Ontario, Canada
Karma: 3
Senior Member
Emery,
Thanks for confirming my suspicions about the purpose of the booster bracket. I also added flat washers on the firewall mounting bolts to spread the load.


Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.
1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that
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