Home » Public Forums » GMCnet » Re: [GMCnet] My First Vapor Lock (Vacuum Booster Pumps)
| Re: [GMCnet] My First Vapor Lock (Vacuum Booster Pumps) [message #175426] |
Tue, 03 July 2012 12:55  |
Dave Mumert
Messages: 272
Registered: February 2004
Location: Olds, AB, Canada
Karma: 0
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Senior Member |
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Hi All
I was ignoring this thread, we don't get vapor lock often up here in the
Great White North.
When it comes to making a fail-safe vacuum source for the brake booster I
think you are both wrong.
One of the fundamental principles of fail-safe design is the elimination of
common sources of failure.
The original vacuum source has only three parts, the hose fitting on the
manifold, the hose and the vacuum port on the booster. All these have
proven to be very reliable, as a primary system they should not be modified
in any way.
Adding a vacuum pump in series with the original vacuum hose adds a number
of failure points that are common to both the primary system and the
secondary system which actually reduces reliability. I have to agree with
JB here, don't mess with the original vacuum feed. It has been reported
here that a failed vacuum booster pump not only caused a loss of vacuum to
the booster but also pumped air into the manifold killing the engine.
The little vacuum pump GM used was intended as a vacuum booster and was
plumbed to provide that function. I assume we are attempting to get a
redundant source of vacuum so plumbing the pump as GM did is probably not
the best way.
Adding a vacuum tank by teeing into the original vacuum hose also adds
multiple new failure points.
In my opinion the only way to get a redundant vacuum feed that is (almost)
as reliable as the factory system is to use a booster with dual vacuum
ports.
If you like a vacuum tank hook it to the extra vacuum port and connect it to
its own vacuum port on the manifold.
If you like the idea of a pump then connect it to the extra vacuum port and
let it exhaust to the atmosphere.
I personally like a vacuum pump. The engine will provide less vacuum than
the pump, so in theory you should get better brakes with the pump running.
I would also connect the pump to the brake light switch, through a relay of
course.
These are just my opinions, feel free to ignore them or critique them as you
see fit.
Dave Mumert
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| Re: [GMCnet] My First Vapor Lock (Vacuum Booster Pumps) [message #175498 is a reply to message #175426] |
Wed, 04 July 2012 08:54  |
 |
USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
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Senior Member |
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Dave,
If one installs a booster with a second vacuum port and check valve and
plumbs the aux pump to it they are only adding two components that could
fail and effect the factory system; the check valve and the seal around it.
Regards,
Rob M.
-----Original Message-----
From: Dave Mumert
Hi All
I was ignoring this thread, we don't get vapor lock often up here in the
Great White North.
When it comes to making a fail-safe vacuum source for the brake booster I
think you are both wrong.
One of the fundamental principles of fail-safe design is the elimination of
common sources of failure.
The original vacuum source has only three parts, the hose fitting on the
manifold, the hose and the vacuum port on the booster. All these have
proven to be very reliable, as a primary system they should not be modified
in any way.
Adding a vacuum pump in series with the original vacuum hose adds a number
of failure points that are common to both the primary system and the
secondary system which actually reduces reliability. I have to agree with
JB here, don't mess with the original vacuum feed. It has been reported
here that a failed vacuum booster pump not only caused a loss of vacuum to
the booster but also pumped air into the manifold killing the engine.
The little vacuum pump GM used was intended as a vacuum booster and was
plumbed to provide that function. I assume we are attempting to get a
redundant source of vacuum so plumbing the pump as GM did is probably not
the best way.
Adding a vacuum tank by teeing into the original vacuum hose also adds
multiple new failure points.
In my opinion the only way to get a redundant vacuum feed that is (almost)
as reliable as the factory system is to use a booster with dual vacuum
ports.
If you like a vacuum tank hook it to the extra vacuum port and connect it to
its own vacuum port on the manifold.
If you like the idea of a pump then connect it to the extra vacuum port and
let it exhaust to the atmosphere.
I personally like a vacuum pump. The engine will provide less vacuum than
the pump, so in theory you should get better brakes with the pump running.
I would also connect the pump to the brake light switch, through a relay of
course.
These are just my opinions, feel free to ignore them or critique them as you
see fit.
Dave Mumert
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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
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| Re: [GMCnet] My First Vapor Lock (Vacuum Booster Pumps) [message #175610 is a reply to message #175426] |
Thu, 05 July 2012 10:05 |
Richard Denney
Messages: 920
Registered: April 2010
Karma: 9
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Senior Member |
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On Tue, Jul 3, 2012 at 1:55 PM, Dave Mumert <gmcnet@mumert.com> wrote:
> One of the fundamental principles of fail-safe design is the elimination of
> common sources of failure.
Gene is right. The existing system only works when the engine is
providing vacuum, and there are too many situations where that does
not happen, following by the need to be able to move and control the
vehicle using gravity and brakes only. One cannot assess the
reliability of the system without considering the reliability of the
source of the vacuum in the first place.
The strategy here is not to provide fail-safe reliability of that
source, which cannot be guaranteed, but rather to provide a redundant
source when needed. This may require reducing the reliability of the
existing arrangement slightly, though, as you say, it only reduces the
reliability of the high-reliability components, while addressing the
critical issue of the low-reliability component--the engine.
My own approach provides two redundancies. And both are separated from
the engine by the same type of check valve used with the booster. That
check valve has to fail before a failed pump diaphragm can cause a
loss of engine vacuum. I don't see much loss of reliability there. I'm
more concerned about the hose from there to the intake manifold, which
is subject to rodent nibbling. I used stainless steel braided hose to
prevent that problem.
The pump is not going to provide the reliability of a tank, but in
return for that, it provides a test of its operation every time I turn
on the coach. That minimizes the probability of a failure at a time of
need--most failures of backup systems occur when there is no need and
people don't notice it because they dont' test it. This systems gets
tested routinely by its nature. I did not plumb mine in series,
however, so that a failed pump would not inhibit the other redundancy.
And that other redundancy is a steel tank, made for this purpose with
the appropriate fittings for same check valve used in boosters. It is
at least as reliable as the booster fittings. But even if it fails,
there is still the storage in the booster.
I've only had two situations in nine years of ownership where I needed
to control the vehicle using the brakes in the absence of the primary
vacuum source of the engine. One (fuel starvation on an uphill) was
the result of poor maintenance, but not the sort of maintenance
problem can't still sneak up on a conscientious owner. The other was
caused by lousy gasoline, and not in an owner's control.
Rick "pretty cautious when arguing engineering principles with Dave!" Denney
--
'73 230 "Jaws"
Northern Virginia
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| Re: [GMCnet] My First Vapor Lock (Vacuum Booster Pumps) [message #175710 is a reply to message #175610] |
Thu, 05 July 2012 21:44 |
mickeysss
Messages: 1476
Registered: January 2012
Karma: 0
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Senior Member |
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being a bird in the coal mine here - i like this system with the steel hoses and both systems and separated. this seems really good.
I read it but i cannot picture it in my minds eye. I want a parts list to buy and where to buy it and a map how to put it together
if possible. If anyone is close to anaheim and wants to do it for me with this system i am very willing to pay good for it, or
take the plans and do it myself. Thanks to everyone for the great participation in viewing this problem. It is a highly needed view
for all of us. Can someone put this list of best parts and how they go together best on the band wagon for us all. I will donate for this
is priceless information. I did not know that when the engine is toping off the vacuum is low as well. This vacuum system is very
critical to the gmc systematic operation. The last thing i want to do is be killed by a mouse when I live at disneyland next door and make a living
from a people visiting a mouse.
Please help me get this right
i see the pictures of just the extra pump - i do not see where the one way valves go, or how to have a separate inlet to the booster or the second
booster. I get the idea and what is this steel hose line made by of from. thanks again for pushing this through the keys at us all.
thank you mickey
On Jul 5, 2012, at 8:05 AM, Richard Denney wrote:
> On Tue, Jul 3, 2012 at 1:55 PM, Dave Mumert <gmcnet@mumert.com> wrote:
>> One of the fundamental principles of fail-safe design is the elimination of
>> common sources of failure.
>
> Gene is right. The existing system only works when the engine is
> providing vacuum, and there are too many situations where that does
> not happen, following by the need to be able to move and control the
> vehicle using gravity and brakes only. One cannot assess the
> reliability of the system without considering the reliability of the
> source of the vacuum in the first place.
>
> The strategy here is not to provide fail-safe reliability of that
> source, which cannot be guaranteed, but rather to provide a redundant
> source when needed. This may require reducing the reliability of the
> existing arrangement slightly, though, as you say, it only reduces the
> reliability of the high-reliability components, while addressing the
> critical issue of the low-reliability component--the engine.
>
> My own approach provides two redundancies. And both are separated from
> the engine by the same type of check valve used with the booster. That
> check valve has to fail before a failed pump diaphragm can cause a
> loss of engine vacuum. I don't see much loss of reliability there. I'm
> more concerned about the hose from there to the intake manifold, which
> is subject to rodent nibbling. I used stainless steel braided hose to
> prevent that problem.
>
> The pump is not going to provide the reliability of a tank, but in
> return for that, it provides a test of its operation every time I turn
> on the coach. That minimizes the probability of a failure at a time of
> need--most failures of backup systems occur when there is no need and
> people don't notice it because they dont' test it. This systems gets
> tested routinely by its nature. I did not plumb mine in series,
> however, so that a failed pump would not inhibit the other redundancy.
> And that other redundancy is a steel tank, made for this purpose with
> the appropriate fittings for same check valve used in boosters. It is
> at least as reliable as the booster fittings. But even if it fails,
> there is still the storage in the booster.
>
> I've only had two situations in nine years of ownership where I needed
> to control the vehicle using the brakes in the absence of the primary
> vacuum source of the engine. One (fuel starvation on an uphill) was
> the result of poor maintenance, but not the sort of maintenance
> problem can't still sneak up on a conscientious owner. The other was
> caused by lousy gasoline, and not in an owner's control.
>
> Rick "pretty cautious when arguing engineering principles with Dave!" Denney
>
> --
> '73 230 "Jaws"
> Northern Virginia
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
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| Re: [GMCnet] My First Vapor Lock (Vacuum Booster Pumps) [message #175717 is a reply to message #175710] |
Thu, 05 July 2012 23:25 |
Dave Mumert
Messages: 272
Registered: February 2004
Location: Olds, AB, Canada
Karma: 0
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Senior Member |
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Hi Mickey
Here is a photo of a dual port booster.
http://www.gmccoop.com/images/Brake-booster-new.jpg
This one is from Jim Bounds.
On the upper left is the vacuum port which is also a check valve that holds
vacuum in the booster. On the lower right is a rubber plug that is sealing
up the hole where a second vacuum port would go. The original GMC booster
has only a single port.
To get a redundant vacuum source you would install the second vacuum port
and connect it directly to a vacuum pump. You can control the vacuum pump
with a vacuum switch that regulates the vacuum level or you could control
the pump using the brake light switch.
If you use the brake light to control the pump you would have it running
whenever you used the brakes. It is a simple, too simple for some, solution
with very few extra parts. The advantage is the simplicity plus the
reassurance it is working because you here it every time you use the brakes.
The disadvantage is you here it every time you use the brakes and the pump
will wear out sooner.
Using a vacuum switch is a bit more complicated mainly in the plumbing. If
the vacuum switch is set too low you may not hear the pump operating on a
regular basis, that is not a good thing for a backup system, the operation
needs to be confirmed frequently.
I didn't mention vacuum tanks, I consider them to be a reserve vacuum
source not a redundant vacuum source. I have been on many two lane mountain
roads where it would take far more than 5-6 brake application to get to a
safe pullout area. I don't think I have the strength to man handle the
steering and brakes at the same time in a calm situation let alone on a
curvy mountain rode with a dead engine.
Dave Mumert
> -----Original Message-----
> From: gmclist-bounces@temp.gmcnet.org [mailto:gmclist-
> bounces@temp.gmcnet.org] On Behalf Of Mickey Space Ship Shuttle
> Sent: Thursday, July 05, 2012 8:44 PM
> To: gmclist@temp.gmcnet.org
> Subject: Re: [GMCnet] My First Vapor Lock (Vacuum Booster Pumps)
>
>
> being a bird in the coal mine here - i like this system with the steel
hoses and
> both systems and separated. this seems really good.
>
> I read it but i cannot picture it in my minds eye. I want a parts list to
buy and
> where to buy it and a map how to put it together
>
> if possible. If anyone is close to anaheim and wants to do it for me with
this
> system i am very willing to pay good for it, or
>
> take the plans and do it myself. Thanks to everyone for the great
> participation in viewing this problem. It is a highly needed view
>
> for all of us. Can someone put this list of best parts and how they go
together
> best on the band wagon for us all. I will donate for this
>
> is priceless information. I did not know that when the engine is toping
off the
> vacuum is low as well. This vacuum system is very
>
> critical to the gmc systematic operation. The last thing i want to do is
be killed
> by a mouse when I live at disneyland next door and make a living
>
> from a people visiting a mouse.
>
> Please help me get this right
>
> i see the pictures of just the extra pump - i do not see where the one way
> valves go, or how to have a separate inlet to the booster or the second
>
> booster. I get the idea and what is this steel hose line made by of from.
> thanks again for pushing this through the keys at us all.
>
> thank you mickey
>
>
>
>
> On Jul 5, 2012, at 8:05 AM, Richard Denney wrote:
>
> > On Tue, Jul 3, 2012 at 1:55 PM, Dave Mumert <gmcnet@mumert.com>
> wrote:
> >> One of the fundamental principles of fail-safe design is the
> >> elimination of common sources of failure.
> >
> > Gene is right. The existing system only works when the engine is
> > providing vacuum, and there are too many situations where that does
> > not happen, following by the need to be able to move and control the
> > vehicle using gravity and brakes only. One cannot assess the
> > reliability of the system without considering the reliability of the
> > source of the vacuum in the first place.
> >
> > The strategy here is not to provide fail-safe reliability of that
> > source, which cannot be guaranteed, but rather to provide a redundant
> > source when needed. This may require reducing the reliability of the
> > existing arrangement slightly, though, as you say, it only reduces the
> > reliability of the high-reliability components, while addressing the
> > critical issue of the low-reliability component--the engine.
> >
> > My own approach provides two redundancies. And both are separated
> from
> > the engine by the same type of check valve used with the booster. That
> > check valve has to fail before a failed pump diaphragm can cause a
> > loss of engine vacuum. I don't see much loss of reliability there. I'm
> > more concerned about the hose from there to the intake manifold, which
> > is subject to rodent nibbling. I used stainless steel braided hose to
> > prevent that problem.
> >
> > The pump is not going to provide the reliability of a tank, but in
> > return for that, it provides a test of its operation every time I turn
> > on the coach. That minimizes the probability of a failure at a time of
> > need--most failures of backup systems occur when there is no need and
> > people don't notice it because they dont' test it. This systems gets
> > tested routinely by its nature. I did not plumb mine in series,
> > however, so that a failed pump would not inhibit the other redundancy.
> > And that other redundancy is a steel tank, made for this purpose with
> > the appropriate fittings for same check valve used in boosters. It is
> > at least as reliable as the booster fittings. But even if it fails,
> > there is still the storage in the booster.
> >
> > I've only had two situations in nine years of ownership where I needed
> > to control the vehicle using the brakes in the absence of the primary
> > vacuum source of the engine. One (fuel starvation on an uphill) was
> > the result of poor maintenance, but not the sort of maintenance
> > problem can't still sneak up on a conscientious owner. The other was
> > caused by lousy gasoline, and not in an owner's control.
> >
> > Rick "pretty cautious when arguing engineering principles with Dave!"
> > Denney
> >
> > --
> > '73 230 "Jaws"
> > Northern Virginia
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| Re: [GMCnet] My First Vapor Lock (Vacuum Booster Pumps) [message #175719 is a reply to message #175717] |
Fri, 06 July 2012 00:50 |
mickeysss
Messages: 1476
Registered: January 2012
Karma: 0
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Senior Member |
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Thank you, i just put a sensitive new booster on and have a new extra pump from jimK, with the bracket and plug on the way.
I think i have to go now with the two pump, one booster but maybe a the JimB tank made from tubes or something plan, along with it.
I could start all over with this but if i drive it more than i do now i may replace it all, but for now i do not know what i a doing but this is
really a great idea to have a double tank. But i just paid for the other one. I will go with two pumps first. Is it best to connect it to the stop light
or use the 5 second pressure switch, or take it off the yellow wire on the heater blower. I wish i could have been aware of all this before i
spent the money for this system. It takes a while to get this all right. It is buyer takes the dare. If i had the info with the double tank i would have
gone that route. Now i think for a while i will go with the pictures of two pumps, for i have that in hand now almost.
How do you wire this with two pumps and is this to the brake pedal for the second pump? or the yellow wire to the blower motor.
where do i put the one way valves. and i think i need four pieces of tubing, and two check valves or so. I will go to the blue page and check it out.
At minimum it seems a person that lives in hills needs two pumps.
Thank you dave.
On Jul 5, 2012, at 9:25 PM, Dave Mumert wrote:
> Hi Mickey
>
> Here is a photo of a dual port booster.
> http://www.gmccoop.com/images/Brake-booster-new.jpg
> This one is from Jim Bounds.
>
> On the upper left is the vacuum port which is also a check valve that holds
> vacuum in the booster. On the lower right is a rubber plug that is sealing
> up the hole where a second vacuum port would go. The original GMC booster
> has only a single port.
>
> To get a redundant vacuum source you would install the second vacuum port
> and connect it directly to a vacuum pump. You can control the vacuum pump
> with a vacuum switch that regulates the vacuum level or you could control
> the pump using the brake light switch.
>
> If you use the brake light to control the pump you would have it running
> whenever you used the brakes. It is a simple, too simple for some, solution
> with very few extra parts. The advantage is the simplicity plus the
> reassurance it is working because you here it every time you use the brakes.
> The disadvantage is you here it every time you use the brakes and the pump
> will wear out sooner.
>
> Using a vacuum switch is a bit more complicated mainly in the plumbing. If
> the vacuum switch is set too low you may not hear the pump operating on a
> regular basis, that is not a good thing for a backup system, the operation
> needs to be confirmed frequently.
>
> I didn't mention vacuum tanks, I consider them to be a reserve vacuum
> source not a redundant vacuum source. I have been on many two lane mountain
> roads where it would take far more than 5-6 brake application to get to a
> safe pullout area. I don't think I have the strength to man handle the
> steering and brakes at the same time in a calm situation let alone on a
> curvy mountain rode with a dead engine.
>
> Dave Mumert
>
>
>
>> -----Original Message-----
>> From: gmclist-bounces@temp.gmcnet.org [mailto:gmclist-
>> bounces@temp.gmcnet.org] On Behalf Of Mickey Space Ship Shuttle
>> Sent: Thursday, July 05, 2012 8:44 PM
>> To: gmclist@temp.gmcnet.org
>> Subject: Re: [GMCnet] My First Vapor Lock (Vacuum Booster Pumps)
>>
>>
>> being a bird in the coal mine here - i like this system with the steel
> hoses and
>> both systems and separated. this seems really good.
>>
>> I read it but i cannot picture it in my minds eye. I want a parts list to
> buy and
>> where to buy it and a map how to put it together
>>
>> if possible. If anyone is close to anaheim and wants to do it for me with
> this
>> system i am very willing to pay good for it, or
>>
>> take the plans and do it myself. Thanks to everyone for the great
>> participation in viewing this problem. It is a highly needed view
>>
>> for all of us. Can someone put this list of best parts and how they go
> together
>> best on the band wagon for us all. I will donate for this
>>
>> is priceless information. I did not know that when the engine is toping
> off the
>> vacuum is low as well. This vacuum system is very
>>
>> critical to the gmc systematic operation. The last thing i want to do is
> be killed
>> by a mouse when I live at disneyland next door and make a living
>>
>> from a people visiting a mouse.
>>
>> Please help me get this right
>>
>> i see the pictures of just the extra pump - i do not see where the one way
>> valves go, or how to have a separate inlet to the booster or the second
>>
>> booster. I get the idea and what is this steel hose line made by of from.
>> thanks again for pushing this through the keys at us all.
>>
>> thank you mickey
>>
>>
>>
>>
>> On Jul 5, 2012, at 8:05 AM, Richard Denney wrote:
>>
>>> On Tue, Jul 3, 2012 at 1:55 PM, Dave Mumert <gmcnet@mumert.com>
>> wrote:
>>>> One of the fundamental principles of fail-safe design is the
>>>> elimination of common sources of failure.
>>>
>>> Gene is right. The existing system only works when the engine is
>>> providing vacuum, and there are too many situations where that does
>>> not happen, following by the need to be able to move and control the
>>> vehicle using gravity and brakes only. One cannot assess the
>>> reliability of the system without considering the reliability of the
>>> source of the vacuum in the first place.
>>>
>>> The strategy here is not to provide fail-safe reliability of that
>>> source, which cannot be guaranteed, but rather to provide a redundant
>>> source when needed. This may require reducing the reliability of the
>>> existing arrangement slightly, though, as you say, it only reduces the
>>> reliability of the high-reliability components, while addressing the
>>> critical issue of the low-reliability component--the engine.
>>>
>>> My own approach provides two redundancies. And both are separated
>> from
>>> the engine by the same type of check valve used with the booster. That
>>> check valve has to fail before a failed pump diaphragm can cause a
>>> loss of engine vacuum. I don't see much loss of reliability there. I'm
>>> more concerned about the hose from there to the intake manifold, which
>>> is subject to rodent nibbling. I used stainless steel braided hose to
>>> prevent that problem.
>>>
>>> The pump is not going to provide the reliability of a tank, but in
>>> return for that, it provides a test of its operation every time I turn
>>> on the coach. That minimizes the probability of a failure at a time of
>>> need--most failures of backup systems occur when there is no need and
>>> people don't notice it because they dont' test it. This systems gets
>>> tested routinely by its nature. I did not plumb mine in series,
>>> however, so that a failed pump would not inhibit the other redundancy.
>>> And that other redundancy is a steel tank, made for this purpose with
>>> the appropriate fittings for same check valve used in boosters. It is
>>> at least as reliable as the booster fittings. But even if it fails,
>>> there is still the storage in the booster.
>>>
>>> I've only had two situations in nine years of ownership where I needed
>>> to control the vehicle using the brakes in the absence of the primary
>>> vacuum source of the engine. One (fuel starvation on an uphill) was
>>> the result of poor maintenance, but not the sort of maintenance
>>> problem can't still sneak up on a conscientious owner. The other was
>>> caused by lousy gasoline, and not in an owner's control.
>>>
>>> Rick "pretty cautious when arguing engineering principles with Dave!"
>>> Denney
>>>
>>> --
>>> '73 230 "Jaws"
>>> Northern Virginia
>
> _______________________________________________
> GMCnet mailing list
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> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
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| Re: [GMCnet] My First Vapor Lock (Vacuum Booster Pumps) [message #175732 is a reply to message #175719] |
Fri, 06 July 2012 08:13 |
powerjon
Messages: 2446
Registered: January 2004
Karma: 5
|
Senior Member |
|
|
To All,
I used a Hobbs pressure sw to control the vacuum pump. See the following pictures.
<http://www.gmcmhphotos.com/photos/g3145-vacuum-pump-vacuum-switch.html>
J.R. Wright
GMC GreatLaker
GMC Eastern States
GMCMI
78 Buskirk 30' Stretch
1975 Avion (Under Reconstruction)
Michigan
On Jul 6, 2012, at 1:50 AM, Mickey Space Ship Shuttle wrote:
> Thank you, i just put a sensitive new booster on and have a new extra pump from jimK, with the bracket and plug on the way.
>
> I think i have to go now with the two pump, one booster but maybe a the JimB tank made from tubes or something plan, along with it.
>
> I could start all over with this but if i drive it more than i do now i may replace it all, but for now i do not know what i a doing but this is
>
> really a great idea to have a double tank. But i just paid for the other one. I will go with two pumps first. Is it best to connect it to the stop light
>
> or use the 5 second pressure switch, or take it off the yellow wire on the heater blower. I wish i could have been aware of all this before i
>
> spent the money for this system. It takes a while to get this all right. It is buyer takes the dare. If i had the info with the double tank i would have
>
> gone that route. Now i think for a while i will go with the pictures of two pumps, for i have that in hand now almost.
>
> How do you wire this with two pumps and is this to the brake pedal for the second pump? or the yellow wire to the blower motor.
>
> where do i put the one way valves. and i think i need four pieces of tubing, and two check valves or so. I will go to the blue page and check it out.
>
> At minimum it seems a person that lives in hills needs two pumps.
>
> Thank you dave.
>
>
> On Jul 5, 2012, at 9:25 PM, Dave Mumert wrote:
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J.R. Wright
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GMC Eastern States
GMCMI
78 30' Buskirk Stretch
75 Avion Under Reconstruction
Michigan
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| Re: [GMCnet] My First Vapor Lock (Vacuum Booster Pumps) [message #175755 is a reply to message #175710] |
Fri, 06 July 2012 10:29 |
Richard Denney
Messages: 920
Registered: April 2010
Karma: 9
|
Senior Member |
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On Thu, Jul 5, 2012 at 10:44 PM, Mickey Space Ship Shuttle
<mickeysss@me.com> wrote:
>
> I read it but i cannot picture it in my minds eye.
I used this vacuum reservoir:
http://www.summitracing.com/parts/SUM-G1464/
It has the incoming check valve already installed, plus two other 3/8"
hose barbs. I ran Spectre 3/8" fuel line with stainless braid from
that check valve to the intake manifold fitting.
The vacuum pump is from a mid-80's GM sedan, and I bought it from
anothe member of GMCnet many years ago. Any good vacuum pump will
work. The GM pump is designed to be plumbed in series (intake to pump
to booster), I ran a 3/8" fuel hose from one of those 3/8" hose barbs
through an inline filter to the input of the pump. That particular
pump has a built-in vacuum switch and check valve. I just left the
output open to the air. The filter helps prevent a backfire or some
other intake-manifold mishap from blowing out the diaphragm on the
pump. I wired the pump directly to the 12-volt positive terminal on
the coach, through a 30-amp inline fuse holder and 10-gauge wire.
Here's the filter:
http://www.amazon.com/1978-1984-Corvette-Booster-Vacuum-Filter/dp/B001P5ZU2M
I then ran 3/8" fuel hose from the remaining barb on the tank to the
brake booster, though its regular check valve mounted on the booster.
I mounted the pump and the tank on a piece of 2" aluminum flat bar
that I then bolted to the underside of the floor adjacent to the
pedals and steering column area. They hang down into the open space
behind the left headlight.
So, vacuum hose goes from intake manifold to reserve tank check valve.
And from vacuum pump input to inline filter to hose barb on reserve
tank. And from reserve tank to brake booster.
The only thing I'm not too happy about is the hose. I think it can
collapse under sufficient vacuum, and c. I know that many say that
fuel hose works fine for vacuum hose, but I plan to replace it all
with thick-wall vacuum hose (11/32" ID). Dayco 80094 is a part number
for a 50-foot roll of it at Summit. I'll put convoluted wire conduit
over it to give the rodents something extra to chew on.
Rick "on flaky dialup-speed mobile connection and can't upload pictures" Denney
--
'73 230 "Jaws"
Northern Virginia
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| Re: [GMCnet] My First Vapor Lock (Vacuum Booster Pumps) [message #175764 is a reply to message #175732] |
Fri, 06 July 2012 11:21 |
|
|
Yiu
On Jul 6, 2012 8:13 AM, "John Wright" <powerjon@chartermi.net> wrote:
> To All,
> I used a Hobbs pressure sw to control the vacuum pump. See the following
> pictures.
>
> <http://www.gmcmhphotos.com/photos/g3145-vacuum-pump-vacuum-switch.html>
>
> J.R. Wright
> GMC GreatLaker
> GMC Eastern States
> GMCMI
> 78 Buskirk 30' Stretch
> 1975 Avion (Under Reconstruction)
> Michigan
>
> On Jul 6, 2012, at 1:50 AM, Mickey Space Ship Shuttle wrote:
>
> > Thank you, i just put a sensitive new booster on and have a new extra
> pump from jimK, with the bracket and plug on the way.
> >
> > I think i have to go now with the two pump, one booster but maybe a the
> JimB tank made from tubes or something plan, along with it.
> >
> > I could start all over with this but if i drive it more than i do now i
> may replace it all, but for now i do not know what i a doing but this is
> >
> > really a great idea to have a double tank. But i just paid for the other
> one. I will go with two pumps first. Is it best to connect it to the stop
> light
> >
> > or use the 5 second pressure switch, or take it off the yellow wire on
> the heater blower. I wish i could have been aware of all this before i
> >
> > spent the money for this system. It takes a while to get this all right.
> It is buyer takes the dare. If i had the info with the double tank i would
> have
> >
> > gone that route. Now i think for a while i will go with the pictures of
> two pumps, for i have that in hand now almost.
> >
> > How do you wire this with two pumps and is this to the brake pedal for
> the second pump? or the yellow wire to the blower motor.
> >
> > where do i put the one way valves. and i think i need four pieces of
> tubing, and two check valves or so. I will go to the blue page and check it
> out.
> >
> > At minimum it seems a person that lives in hills needs two pumps.
> >
> > Thank you dave.
> >
> >
> > On Jul 5, 2012, at 9:25 PM, Dave Mumert wrote:
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
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bdub
bdub.net
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| Re: [GMCnet] My First Vapor Lock (Vacuum Booster Pumps) [message #175783 is a reply to message #175755] |
Fri, 06 July 2012 13:19 |
mickeysss
Messages: 1476
Registered: January 2012
Karma: 0
|
Senior Member |
|
|
i am printing these all out to go over later thank you.
faithfully, mickey
On Jul 6, 2012, at 8:29 AM, Richard Denney wrote:
> On Thu, Jul 5, 2012 at 10:44 PM, Mickey Space Ship Shuttle
> <mickeysss@me.com> wrote:
>>
>> I read it but i cannot picture it in my minds eye.
>
> I used this vacuum reservoir:
>
> http://www.summitracing.com/parts/SUM-G1464/
>
> It has the incoming check valve already installed, plus two other 3/8"
> hose barbs. I ran Spectre 3/8" fuel line with stainless braid from
> that check valve to the intake manifold fitting.
>
> The vacuum pump is from a mid-80's GM sedan, and I bought it from
> anothe member of GMCnet many years ago. Any good vacuum pump will
> work. The GM pump is designed to be plumbed in series (intake to pump
> to booster), I ran a 3/8" fuel hose from one of those 3/8" hose barbs
> through an inline filter to the input of the pump. That particular
> pump has a built-in vacuum switch and check valve. I just left the
> output open to the air. The filter helps prevent a backfire or some
> other intake-manifold mishap from blowing out the diaphragm on the
> pump. I wired the pump directly to the 12-volt positive terminal on
> the coach, through a 30-amp inline fuse holder and 10-gauge wire.
>
> Here's the filter:
>
> http://www.amazon.com/1978-1984-Corvette-Booster-Vacuum-Filter/dp/B001P5ZU2M
>
> I then ran 3/8" fuel hose from the remaining barb on the tank to the
> brake booster, though its regular check valve mounted on the booster.
>
> I mounted the pump and the tank on a piece of 2" aluminum flat bar
> that I then bolted to the underside of the floor adjacent to the
> pedals and steering column area. They hang down into the open space
> behind the left headlight.
>
> So, vacuum hose goes from intake manifold to reserve tank check valve.
> And from vacuum pump input to inline filter to hose barb on reserve
> tank. And from reserve tank to brake booster.
>
> The only thing I'm not too happy about is the hose. I think it can
> collapse under sufficient vacuum, and c. I know that many say that
> fuel hose works fine for vacuum hose, but I plan to replace it all
> with thick-wall vacuum hose (11/32" ID). Dayco 80094 is a part number
> for a 50-foot roll of it at Summit. I'll put convoluted wire conduit
> over it to give the rodents something extra to chew on.
>
> Rick "on flaky dialup-speed mobile connection and can't upload pictures" Denney
>
> --
> '73 230 "Jaws"
> Northern Virginia
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
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| Re: [GMCnet] My First Vapor Lock (Vacuum Booster Pumps) [message #175792 is a reply to message #175755] |
Fri, 06 July 2012 15:08 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
|
Senior Member |
|
|
Rick,
The math just doesn't argue in favor of your reservoir choice:
For simplicity, I'm just using external dimensions:
Summit: 3.14*(5/2)*(5/2)*6.75=132.5 ci for $34.95.
Home Made PVC: 3.14*(4/2)*(4/2)*30=376.8 ci for maybe $15, including 30"
of 4" OD Sched. 40 PVC, 2 end caps, a junk yard brake booster check valve,
and a brass pipe thread to 3/8" hose barb nipple. Plus a little Shoe Goo
or other heavy bodied sealer and some PVC cement.
The tube's even easier to mount: Just TyWrap it inside the #1 cross
member. It should give about 3 more full boost stops. By extension, your
Summit reservoir should give only one more.
For my personal one, I added a small nipple for the HVAC vacuum, and a
second 3/8" one for the electric boost pump (which has an internal check
valve).
Ken H.
On Fri, Jul 6, 2012 at 11:29 AM, Richard Denney wrote:
>
> I used this vacuum reservoir:
>
> http://www.summitracing.com/parts/SUM-G1464/
>
> It has the incoming check valve already installed, plus two other 3/8"
> hose barbs. I ran Spectre 3/8" fuel line with stainless braid from
> that check valve to the intake manifold fitting.
> ...
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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| Re: [GMCnet] My First Vapor Lock (Vacuum Booster Pumps) [message #175795 is a reply to message #175793] |
Fri, 06 July 2012 15:46 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
|
Senior Member |
|
|
Rick,
I haven't really thought through the pump vs reservoir implications. I
just installed a Cad suspension compressor as the vacuum pump, considering
it more reliable than the old Delco pumps at this stage of their life (I've
got a bunch of them with ruptured diaphragms). With the booster
+ reservoir giving me a total of 4-5 boosted stops, I should have time to
manually turn on that pump so it can begin to maintain &/or restore the
reservoir. If I were (as I should) to install a vacuum switch, I'd want to
set it to come on very early so it wouldn't have much catching up to do. I
do have (have had for many years) a good quality, adjustable, vacuum
switch. Maybe some day I'll find a round tuit to go with it.
Ken H.
On Fri, Jul 6, 2012 at 4:27 PM, Richard Denney wrote:
>
> No argument. It's small. But it's also easy for people with too little
> time. I would not use that reservoir without the pump--it's worth
> maybe another pump or two of the brake pedal on top of what the
> booster stores.
>
> The bigger the combiined reservoir and booster, though, the bigger the
> vacuum pump needs to be to draw them down as fast as my panicky right
> foot might empty them. Has anyone tested how long it takes to pump
> them down? (I have not.)
>
> But I was asked what I used, and that's what I used.
>
> Rick "not sure if there's an optimal relationship between reservoir
> and pump size" Denney
>
>
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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| Re: [GMCnet] My First Vapor Lock (Vacuum Booster Pumps) [message #175847 is a reply to message #175732] |
Sat, 07 July 2012 05:52 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
|
Senior Member |
|
|
I fail to understand this idea of wiring the pump to the brake lights. By the time you step on the brakes with no vacuum available it is too late.
Wire the pump to a vacuum switch and the pump will come on anytime the vacuum level is low.
My GM pump came with a built in vacuum switch.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: [GMCnet] My First Vapor Lock (Vacuum Booster Pumps) [message #175848 is a reply to message #175847] |
Sat, 07 July 2012 06:15 |
Mr ERFisher
Messages: 7117
Registered: August 2005
Karma: 2
|
Senior Member |
|
|
>
> I fail to understand this idea of wiring the pump to the brake lights. By
> the time you step on the brakes with no vacuum available it is too late.
>
> I agree,
this is a real waste of time and dangerous (brake lights are the first to
blow a fuse;>)
we have far too much to do when driving a GMC.
lets DON'T remember to:
- read gauges ----------------------(use digi-panel with alarm)
- turn on electric gas pumps -(run all the time)
- turn on vac boosters ----------(automatic with JC4)
- computer display----------------(save for the shop)
- read the air bag pressure-----(set on travel)
LIFE IS SHORT
this is the only switch I want on my GMC ;>)
(the run button :>)
http://goo.gl/3tkac
GENE
--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html
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