Does a vacuum diagram exist for our coaches? An actual service manual?
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1976 Palm Beach
Austin, TX
--
1976 Palm Beach
Austin, TX
Vacuum diagram
- Thread starter adam metzger
- Start date
http://www.gmcmhphotos.com/photos/search.php?searchid=286204
>
> Does a vacuum diagram exist for our coaches? An actual service manual?
>
> Does a vacuum diagram exist for our coaches? An actual service manual?
> Does a vacuum diagram exist for our coaches? An actual service manual?
Yes. Here's one that shows the engine.
http://www.gmcmhphotos.com/photos/misc-junk/p40243-vacuum-connections.html
There are also vacuum lines to the transmission modulator, the cruise control, and the dash heater/AC actuator "network".
Peruse your Maintenance Manual and see what you can find.
--
73 23' Sequoia 4 Sale
73 23' CanyonLands Parts Unit 4 Sale
Upper Alabama
"Highest price does not guarantee highest quality."
Yes. Here's one that shows the engine.
http://www.gmcmhphotos.com/photos/misc-junk/p40243-vacuum-connections.html
There are also vacuum lines to the transmission modulator, the cruise control, and the dash heater/AC actuator "network".
Peruse your Maintenance Manual and see what you can find.
--
73 23' Sequoia 4 Sale
73 23' CanyonLands Parts Unit 4 Sale
Upper Alabama
"Highest price does not guarantee highest quality."
Thanks. I did just that after posting last night. Was hoping for sort of a master map like a schematic, so I can visualize all the components.
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1976 Palm Beach
Austin, TX
--
1976 Palm Beach
Austin, TX
Here are a few
http://www.gmcmhphotos.com/photos/tvs-and-vacuum/p3341.html
> Thanks. I did just that after posting last night. Was hoping for sort of
> a master map like a schematic, so I can visualize all the components.
> --
> 1976 Palm Beach
> Austin, TX
>
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http://www.gmcmhphotos.com/photos/tvs-and-vacuum/p3341.html
> Thanks. I did just that after posting last night. Was hoping for sort of
> a master map like a schematic, so I can visualize all the components.
> --
> 1976 Palm Beach
> Austin, TX
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
Is it safe to assume that a toronado vacuum diagram wouldn't. E too far off from what I'm working with? I think I'm going to replace all
The vacuum lines so 1) I know they're good and b) It will help me find my way around the engine, and help me understand what is what.
--
1976 Palm Beach
Austin, TX
The vacuum lines so 1) I know they're good and b) It will help me find my way around the engine, and help me understand what is what.
--
1976 Palm Beach
Austin, TX
With all the engine swapping over the last 40 years, knowing exactly what
should be present in your specific coach becomes an interesting
undertaking. I guess you either can look at what you have today and work
backwards through time, or, start with what was supposed to be there as it
left from the factory and go from there. Then, there were GMC factory up
fitted coaches, and Gemini, Avion, Champion, Coachman, and other private up
fitters that added their special touches to the coaches. It really does
make a difference if it is a 49 states coach, or a California equipped one,
particularly on the 77 and 78 year model coaches equipped with the 403
engines. Lots of differences in emissions and vacuum hoses, charcoal
cannisters, air cleaners, etc.
Jim Hupy
Salem, Or
78 GMC ROYALE 403
> Is it safe to assume that a toronado vacuum diagram wouldn't. E too far
> off from what I'm working with? I think I'm going to replace all
> The vacuum lines so 1) I know they're good and b) It will help me find my
> way around the engine, and help me understand what is what.
> --
> 1976 Palm Beach
> Austin, TX
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
should be present in your specific coach becomes an interesting
undertaking. I guess you either can look at what you have today and work
backwards through time, or, start with what was supposed to be there as it
left from the factory and go from there. Then, there were GMC factory up
fitted coaches, and Gemini, Avion, Champion, Coachman, and other private up
fitters that added their special touches to the coaches. It really does
make a difference if it is a 49 states coach, or a California equipped one,
particularly on the 77 and 78 year model coaches equipped with the 403
engines. Lots of differences in emissions and vacuum hoses, charcoal
cannisters, air cleaners, etc.
Jim Hupy
Salem, Or
78 GMC ROYALE 403
> Is it safe to assume that a toronado vacuum diagram wouldn't. E too far
> off from what I'm working with? I think I'm going to replace all
> The vacuum lines so 1) I know they're good and b) It will help me find my
> way around the engine, and help me understand what is what.
> --
> 1976 Palm Beach
> Austin, TX
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
From memory, lets see if I can list all of the devices that run on vacuum and their hoses.
1. Power brakes
a. large hose between intake manifold and power brake booster
2. Transmission modulator
a. hose from front of carb to steel line mounted on pass side front of intake manifold
b. hose from steel line on lower rear of engine to transmission modulator
3. Heater control
a. hose from rear intake manifold vacuum port to heater vacuum, reservoir under
driver's side hood.
b. hose from vac reservoir to heater control under the dash.
4. Cruise control
a. hose from brake pedal disconnect switch to the Cruise Control
b. hose from 2 CC ports to rear intake manifold vacuum port
c. hose from CC to throttle bellows
5. Distributor
a. hose from distributor to TVS
b. hose from TVS to highest port on front of carb
c. hose from TVS to front manifold vacuum port.
6. Fuel canister
a. I forget exactly where this one goes. I believe it goes to a lower port on the
front of the carb.
I did not list all of the vacuum hoses from the heater control to the various doors in the heater/AC system. I do not think you wan to mess with
those.
If anyone one sees any errors or omissions please correct the above list.
This ought to get you started.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
1. Power brakes
a. large hose between intake manifold and power brake booster
2. Transmission modulator
a. hose from front of carb to steel line mounted on pass side front of intake manifold
b. hose from steel line on lower rear of engine to transmission modulator
3. Heater control
a. hose from rear intake manifold vacuum port to heater vacuum, reservoir under
driver's side hood.
b. hose from vac reservoir to heater control under the dash.
4. Cruise control
a. hose from brake pedal disconnect switch to the Cruise Control
b. hose from 2 CC ports to rear intake manifold vacuum port
c. hose from CC to throttle bellows
5. Distributor
a. hose from distributor to TVS
b. hose from TVS to highest port on front of carb
c. hose from TVS to front manifold vacuum port.
6. Fuel canister
a. I forget exactly where this one goes. I believe it goes to a lower port on the
front of the carb.
I did not list all of the vacuum hoses from the heater control to the various doors in the heater/AC system. I do not think you wan to mess with
those.
If anyone one sees any errors or omissions please correct the above list.
This ought to get you started.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
I think you have to include PCV as that is s big planned vacuum leak of sorts by design.
--
John Lebetski
Woodstock, IL
77 Eleganza II
Source America First
--
John Lebetski
Woodstock, IL
77 Eleganza II
Source America First
Thanks John.
I made several changes and additions to the original posting including your suggestion.
The updated posting is here:
http://gmc.mybirdfeeder.net/GMCforum/index.php?t=tree&goto=311226&rid=12
> I think you have to include PCV as that is s big planned vacuum leak of sorts by design.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
I made several changes and additions to the original posting including your suggestion.
The updated posting is here:
http://gmc.mybirdfeeder.net/GMCforum/index.php?t=tree&goto=311226&rid=12
> I think you have to include PCV as that is s big planned vacuum leak of sorts by design.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
> I think you have to include PCV as that is s big planned vacuum leak of sorts by design.
I wouldn't have thought so, since the PCV vents into the breather (BEFORE the throttle butterflies vs AFTER).
--
73 23' Sequoia 4 Sale
73 23' CanyonLands Parts Unit 4 Sale
Upper Alabama
"Highest price does not guarantee highest quality."
I wouldn't have thought so, since the PCV vents into the breather (BEFORE the throttle butterflies vs AFTER).
--
73 23' Sequoia 4 Sale
73 23' CanyonLands Parts Unit 4 Sale
Upper Alabama
"Highest price does not guarantee highest quality."
I updated this thread again: Click below.
> Thanks John.
> I made several changes and additions to the original posting including your suggestion.
>
>
> The updated posting is here:
> http://gmc.mybirdfeeder.net/GMCforum/index.php?t=tree&goto=311226&rid=12
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
> Thanks John.
> I made several changes and additions to the original posting including your suggestion.
>
>
> The updated posting is here:
> http://gmc.mybirdfeeder.net/GMCforum/index.php?t=tree&goto=311226&rid=12
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
No the breather vents from LH valve cover to air cleaner. PCV vents crankase to manifold vacuum through the metered PCV valve. At times of high
demand and low vacuum, the flow can or does reverse. Hence the filter separator on the left valve cover is very important to keep dirt out of engine
AND oil from getting to the air cleaner during high demand.
--
John Lebetski
Woodstock, IL
77 Eleganza II
Source America First
demand and low vacuum, the flow can or does reverse. Hence the filter separator on the left valve cover is very important to keep dirt out of engine
AND oil from getting to the air cleaner during high demand.
--
John Lebetski
Woodstock, IL
77 Eleganza II
Source America First
Ken Burton item 5 there is also a pladtic T involved in the mix. And on the carb there should be a 1" piece to feed the choke pull off This often
splits at the carb and leaks unnoticed.
--
John Lebetski
Woodstock, IL
77 Eleganza II
Source America First
splits at the carb and leaks unnoticed.
--
John Lebetski
Woodstock, IL
77 Eleganza II
Source America First
Ken, you're awesome. This is super helpful.
I'm toying with the idea of using this to create an actual diagram, for
prosperity.
--
1976 Palm Beach
Austin, TX
I'm toying with the idea of using this to create an actual diagram, for
prosperity.
--
1976 Palm Beach
Austin, TX
Feel free to use it as you please. There are already some pictures in the maintenance manual that also might help you. I was just trying to document
everything that I could remember.
Obviously I forgot a few and others added to the list.
The biggest problem I had is I have modified a few things from OEM and I did not want to list those mods in the list as OEM.
I had an engine fire 7 or 8 years ago and as a result I had to replace all of the hoses. My approach was to do each function one at a time. As an
example, I needed to run the hose to the trans modulator. So I determined where it should connect and installed it. Then I needed to run the advance
for the distributor. So I figured out where it went and installed it. Next the heater controls followed by the brake booster, cruise control, etc.,
etc,. I did not use a hose chart, I just did each function one at a time.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
everything that I could remember.
Obviously I forgot a few and others added to the list.
The biggest problem I had is I have modified a few things from OEM and I did not want to list those mods in the list as OEM.
I had an engine fire 7 or 8 years ago and as a result I had to replace all of the hoses. My approach was to do each function one at a time. As an
example, I needed to run the hose to the trans modulator. So I determined where it should connect and installed it. Then I needed to run the advance
for the distributor. So I figured out where it went and installed it. Next the heater controls followed by the brake booster, cruise control, etc.,
etc,. I did not use a hose chart, I just did each function one at a time.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
Ken here is the short feed to the choke pulloff. Thanks. There is also the email emissions throttle "stop, kicker, dashpot, idle speed modulator"
stuff on the drivers side of the carb on some (California?) though this is long gone on most.
--
John Lebetski
Woodstock, IL
77 Eleganza II
Source America First
stuff on the drivers side of the carb on some (California?) though this is long gone on most.
--
John Lebetski
Woodstock, IL
77 Eleganza II
Source America First
Sorry tried to get picture under 1K by emailing to myself but not working as file too big.
--
John Lebetski
Woodstock, IL
77 Eleganza II
Source America First
--
John Lebetski
Woodstock, IL
77 Eleganza II
Source America First
