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Vacuum pump question

Yahoo Message Number: 8283
This is a 1998 Allure. There is a vacuum pump in the front driver's side compartment underneat the driver. The pump runs continuously and is quite loud. I disconnected the air line and confirmed that what ever it is connected to will hold a vacuum. Then I turned on the pump and, with the hose still disconnected plugged the intake end where it goes.

I would expect the pump to build up to a certain pressure and then shut off. Instead, it does draw some vacuum but does not shut off even when the suction inlet is plugged. Appears to me this pump is bad. Is this a reasonable assumption? Is there any aftermarket place I could get this pump?

Thanks.

Dan & Ann

1998 Allure #30180

Re: Vacuum pump question

Reply #1 –
Yahoo Message Number: 8284
Hi Dan,

The vacuum servo motors and the dash A/C controls are from Specific Climate Systems, Fort Worth Texas, 817 293 5313. They may be able to tell you the source for the vacuum pump/pressure switch. Be sure the two hoses on the pump are connected properly in addition to the hose feeding the control head dash selector. If one of those hoses is disconnected, the vacuum pump runs continuously. Otherwise suck it up and buy it from CCI. CCI did not document the plumbing in the coach manual.
Fred Kovol

2000 Allure 30593

Re: Vacuum pump question

Reply #2 –
Yahoo Message Number: 8285
Fred, the vacuum pump is a Gast Model MOA V111-JH. It has only one hose attached to it. As noted previously, I disconnected that hose and sucked on it real hard to see if it would pass air, but it seems to be tight. Then, with that hose still off, I plugged up the intake nipple of the Gast pump and plugged it in to see if it would shut down under pressure. It did not, just keeps running. Seems to develop a pretty healthy suction but runs continuously.

Dan

Quote from: fredkovol

Hi Dan,

The vacuum servo motors and the dash A/C controls are from

Specific

Quote
Climate Systems, Fort Worth Texas, 817 293 5313. They may be able

to

Quote
tell you the source for the vacuum pump/pressure switch. Be sure

the

Quote
two hoses on the pump are connected properly in addition to the

hose

Quote
feeding the control head dash selector. If one of those hoses is > disconnected, the vacuum pump runs continuously. Otherwise suck it

up

Quote
and buy it from CCI. CCI did not document the plumbing in the

coach

Quote
manual.
Fred Kovol

2000 Allure 30593

> This is a 1998 Allure. There is a vacuum pump in the front

driver's

Quote
side compartment underneat the driver. The pump runs

continuously

Quote
and is quite loud. I disconnected the air line and confirmed

that

Quote
what ever it is connected to will hold a vacuum. Then I turned

on

Quote
the pump and, with the hose still disconnected plugged the

intake

Quote
end where it goes.
>

> I would expect the pump to build up to a certain pressure and

then

Quote
shut off. Instead, it does draw some vacuum but does not shut

off

Quote
even when the suction inlet is plugged. Appears to me this pump

is

Re: Vacuum pump question

Reply #3 –
Yahoo Message Number: 8286
I am watching this thread with interest. I have the same problem with my vacuum pump. What I did as an interim fix is to put an on/off switch on the dash. I use the dash heat/ac so little before plunking down lots of money for a new pump I did this. I did not investigate the cost but read somewhere it is quite expensive. I would be very interested in how you resolve this problem.

" There is a vacuum pump in the front driver's side compartment underneath the driver. The pump runs continuously and is quite loud. "

Sincerely

George W Becker

gwb36@... 1999 Country Coach Intrigue #10700

Re: Vacuum pump question

Reply #4 –
Yahoo Message Number: 8287
I may be able to have the pump repaired by Gast. I'll find out about this on Monday and will post what I find out here.

Dan & Ann

1998 Allure #30180

Quote from: George Becker
> I am watching this thread with interest. I have the same problem

with my

Quote
vacuum pump. What I did as an interim fix is to put an on/off
switch on the

Quote
dash. I use the dash heat/ac so little before plunking down lots

of money

Quote
for a new pump I did this. I did not investigate the cost but read

somewhere

Quote
it is quite expensive. I would be very interested in how you

resolve this

Re: Vacuum pump question

Reply #5 –
Yahoo Message Number: 8314
I have no idea as to the design of this system. Or, never had this problem. But sitting here reading this thread, I wonder if everyone has considered another possibility. That is, the cut-off switch is not built into the pump. If it is not, the trace the wiring back from the pump and see if it passes through a vacuum cut-off switch.
The problem may not even be related to the pump. Not sure if the schematics show enough detail on this system. I do not have my books handy. Let us know what is found.

Jim Hughes

2000 Allure #30511

Quote from: mainecoons0
This is a 1998 Allure. There is a vacuum pump in the front

driver's

Re: Vacuum pump question

Reply #6 –
Yahoo Message Number: 8315
If you go to the Gast site and pull up the service manual for this pump, the parts breakout does not show any kind of switch in this pump. So if there is a switch, it is located somewhere else. Now why it isn't located at or near the pump like the pressure switch for the other air pump in that compartment is beyond me.

Dan

1998 Allure #30180

Quote from: Jim Hughes
I have no idea as to the design of this system. Or, never had

this

Quote
problem. But sitting here reading this thread, I wonder if

everyone

Quote
has considered another possibility. That is, the cut-off switch

is

Quote
not built into the pump. If it is not, the trace the wiring back > from the pump and see if it passes through a vacuum cut-off

switch.

Quote
The problem may not even be related to the pump. Not sure if the > schematics show enough detail on this system. I do not have my

books

Quote
handy. Let us know what is found.

Jim Hughes

2000 Allure #30511

[quote author=mainecoons0"

> This is a 1998 Allure. There is a vacuum pump in the front > driver's

> side compartment underneat the driver. The pump runs

continuously

Quote
and is quite loud. I disconnected the air line and confirmed

that

Quote
what ever it is connected to will hold a vacuum. Then I turned

on

Quote
the pump and, with the hose still disconnected plugged the

intake

Quote
end where it goes.
>

> I would expect the pump to build up to a certain pressure and

then

Quote
shut off. Instead, it does draw some vacuum but does not shut

off

Quote
even when the suction inlet is plugged. Appears to me this pump

is

Re: Vacuum pump question

Reply #7 –
Yahoo Message Number: 8322
George, I was able to find a repair kit, #GSTK309, from the local Gast Rep here in town. To find out who your local Gast Rep is, go to this site and click on your state. Most likely your diaphram was bad, that is all that was wrong with this pump. No need to pay $200 for a new one.
Dan

http://www.gastmfg.com/distribution.html
Quote from: George Becker
> I am watching this thread with interest. I have the same problem

with my

Quote
vacuum pump. What I did as an interim fix is to put an on/off
switch on the

Quote
dash. I use the dash heat/ac so little before plunking down lots

of money

Quote
for a new pump I did this. I did not investigate the cost but read

somewhere

Quote
it is quite expensive. I would be very interested in how you

resolve this

Re: Vacuum pump question

Reply #8 –
Yahoo Message Number: 8323
Quote from: mainecoons0
If you go to the Gast site and pull up the service manual for this > pump, the parts breakout does not show any kind of switch in this > pump. So if there is a switch, it is located somewhere else. Now > why it isn't located at or near the pump like the pressure switch > for the other air pump in that compartment is beyond me.

Dan

1998 Allure #30180

[quote author=Jim Hughes"

> I have no idea as to the design of this system. Or, never had > this

> problem. But sitting here reading this thread, I wonder if > everyone

> has considered another possibility. That is, the cut-off switch > is

> not built into the pump. If it is not, the trace the wiring

back

Quote
from the pump and see if it passes through a vacuum cut-off > switch.

> The problem may not even be related to the pump. Not sure if

the

Quote
schematics show enough detail on this system. I do not have my > books

> handy. Let us know what is found.
>

> Jim Hughes

> 2000 Allure #30511
>
>

[quote author=mainecoons0"
>]
> > This is a 1998 Allure. There is a vacuum pump in the front > > driver's

> > side compartment underneat the driver. The pump runs > continuously

> > and is quite loud. I disconnected the air line and confirmed > that

> > what ever it is connected to will hold a vacuum. Then I

turned

Quote
on

> > the pump and, with the hose still disconnected plugged the > intake

> > end where it goes.
> >

> > I would expect the pump to build up to a certain pressure and > then

> > shut off. Instead, it does draw some vacuum but does not shut > off

> > even when the suction inlet is plugged. Appears to me this

pump

Quote
is

> > bad. Is this a reasonable assumption? Is there any

aftermarket

Quote
> place I could get this pump? > > >

> > Thanks.
> >

> > Dan & Ann
> >
I had the same problem on my "98 intrigue my problem was a vacuum switch located behind the passenger side access panel to dash, open access panel and zip tied to a black plastic accumulator ball is plastic tubing w/a small metal pressure switch. lazy days could not find a replacement so they took it apart and cleaned it out. this valve switches the pump off. hope this helps.
Larry

Re: Vacuum pump question

Reply #9 –
Yahoo Message Number: 8332
Yep, I have the same switch, but it is located under the dash access cover. If you remove the two screws on either side of the dash, just above the lip, the whole padded top of the dash comes off and there the switch is. Mine is bad also, won't shut off properly.

These vacuum pumps are built like tanks, if you're having a problem it is most likely this switch.
Dan

Allure #30180

Quote from: lprichard34668
>

[quote author=mainecoons0"

> If you go to the Gast site and pull up the service manual for

this

Quote
pump, the parts breakout does not show any kind of switch in

this

Quote
pump. So if there is a switch, it is located somewhere else.

Now

Quote
why it isn't located at or near the pump like the pressure

switch

Quote
for the other air pump in that compartment is beyond me.
>
> Dan

> 1998 Allure #30180
>
>

[quote author=Jim Hughes"
>]
> > I have no idea as to the design of this system. Or, never had > > this

> > problem. But sitting here reading this thread, I wonder if > > everyone

> > has considered another possibility. That is, the cut-off

switch

Quote
is

> > not built into the pump. If it is not, the trace the wiring > back

> > from the pump and see if it passes through a vacuum cut-off > > switch.

> > The problem may not even be related to the pump. Not sure if > the

> > schematics show enough detail on this system. I do not have

my

Quote
books

> > handy. Let us know what is found.
> >

> > Jim Hughes

> > 2000 Allure #30511
> >
> >

[quote author=mainecoons0"
> >]
> > > This is a 1998 Allure. There is a vacuum pump in the front > > > driver's

> > > side compartment underneat the driver. The pump runs > > continuously

> > > and is quite loud. I disconnected the air line and

confirmed

Quote
that

> > > what ever it is connected to will hold a vacuum. Then I > turned
> on

> > > the pump and, with the hose still disconnected plugged the > > intake

> > > end where it goes.
> > >

> > > I would expect the pump to build up to a certain pressure

and

Quote
then

> > > shut off. Instead, it does draw some vacuum but does not

shut

Quote
off

> > > even when the suction inlet is plugged. Appears to me this > pump
> is

> > > bad. Is this a reasonable assumption? Is there any > aftermarket

> > > place I could get this pump? > > > >

> > > Thanks.
> > >

> > > Dan & Ann
> > >

I had the same problem on my "98 intrigue my problem was a

vacuum

Quote
switch located behind the passenger side access panel to dash,

open

Quote
access panel and zip tied to a black plastic accumulator ball is > plastic tubing w/a small metal pressure switch. lazy days could

not
 

Re: Vacuum pump question

Reply #10 –
Yahoo Message Number: 8333
-I had the same problem, found some debris inside pump preventing an internal valve from closing completly. Just cleaned out and reassembled. Chuck M. 99 Allure 30314--
In Country-Coach-Owners@yahoogroups.com, "mainecoons0" wrote:

Quote
This is a 1998 Allure. There is a vacuum pump in the front

driver's