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Vacuum Pump Fix

Yahoo Message Number: 9847
OK, a number of you have had problems with this vacuum pump that operates the dash air/heat/defroster system and so did we. What I found was that the pump can be rebuilt for less than $12 but you have to order both the "rebuild" kit and the diaphragm. I got on the pump manufacturers web site and looked up the local dealer and ordered the parts from him. Changing them out was a 20 minute job.

And adjusting the cutoff switch is very tricky. You have to tinker with the high level and low level in relationship to each other until the pump will both come on and cut off. If the high level setting is wrong, the pump will run until it "unloads" itself and keep running. I moved mine from where it was installed to up on top of the bracket that braces the instrument cluster so it was easy to reach and fiddle with the adjustments. Then I just "exercised" the air selection switch, causing the pump to kick on and adjusted the high and low until there is always sufficient vacuum to operate the air system but the pump does not run much.

We're hitting the road on Saturday morning for an extended 5 week, 5500 mile trip. Email me if you have questions and I'll try to get to you in a few days.

Dan & Ann

1998 Allure #30180

Re: Vacuum Pump Fix

Reply #1 –
Yahoo Message Number: 9855
Could you please send the links to the web site for the pump as our over the road air is not working right now and thats probably what it is.

Les and Susan Knox
02 Magna Interlude
Coach 6050 CCI 6051
FMCA 172062

Cazenovia, New York

--- mainecoons0 dhhouck@...> wrote:

Quote
OK, a number of you have had problems with this > vacuum pump that

operates the dash air/heat/defroster system and so > did we. What I

found was that the pump can be rebuilt for less than > $12 but you

have to order both the "rebuild" kit and the > diaphragm. I got on

the pump manufacturers web site and looked up the > local dealer and

ordered the parts from him. Changing them out was a > 20 minute job.

And adjusting the cutoff switch is very tricky. You > have to tinker

with the high level and low level in relationship to > each other

until the pump will both come on and cut off. If > the high level

setting is wrong, the pump will run until it > "unloads" itself and

keep running. I moved mine from where it was > installed to up on top

of the bracket that braces the instrument cluster so > it was easy to

reach and fiddle with the adjustments. Then I just > "exercised" the

air selection switch, causing the pump to kick on > and adjusted the

high and low until there is always sufficient vacuum > to operate the

air system but the pump does not run much.

We're hitting the road on Saturday morning for an > extended 5 week,

5500 mile trip. Email me if you have questions and > I'll try to get

to you in a few days.

Dan & Ann

1998 Allure #30180
Yahoo! Domains ? Claim yours for only $14.70/year http://smallbusiness.promotions.yahoo.com/offer

Re: Vacuum Pump Fix

Reply #2 –
Yahoo Message Number: 9856
Your coach is a lot newer than mine. What is the brand of your vaccuum pump? The pump should be located in the forward compartment under the driver's seat.

A pump this new sure shouldn't need a rebuild. Make sure the control switch, located underneath the dash cover, is OK. It seems to change in setting with use.

When you say it is not working, what is it doing? Running continuously or not at all? If not at all, the problem is going to be either electrical, the control switch or something simple like a fuse. If continuously, could be a vaccuum leak, the control switch, or the pump itself.

Dan & Ann
Allure #30180

Quote from: Les Knox\[br\
]

Re: Vacuum Pump Fix

Reply #3 –
Yahoo Message Number: 9858
While on the way to the Knoxville rally, we had the over the road air on and the fans started running slower and slower and finally shut off completely.
After a couple of days off we turned the system on again and got started running but only for an hour.
We are only getting a trickle of air out of the vents.
The overhead blower is working fine. We had the air turned to max when this happened. I'll have to get back to you on the model number tomorrow.

[quote author=Les
Knox

> Could you please send the links to the web site > for

> the pump as our over the road air is not working > right

> now and thats probably what it is.
>

> Les and Susan Knox
> 02 Magna Interlude
> Coach 6050 CCI 6051
> FMCA 172062
>
>
>

> Cazenovia, New York
> --- mainecoons0 wrote:

> > OK, a number of you have had problems with this > > > vacuum pump that

> > operates the dash air/heat/defroster system and > so

> > did we. What I

> > found was that the pump can be rebuilt for less > than

> > $12 but you

> > have to order both the "rebuild" kit and the > > > diaphragm. I got on

> > the pump manufacturers web site and looked up > the

> > local dealer and

> > ordered the parts from him. Changing them out > was a

> > 20 minute job.
> >

> > And adjusting the cutoff switch is very tricky.
You

> > have to tinker

> > with the high level and low level in > relationship to
> > each other

> > until the pump will both come on and cut off.
If

> > the high level

> > setting is wrong, the pump will run until it > > > "unloads" itself and

> > keep running. I moved mine from where it was > > > installed to up on top

> > of the bracket that braces the instrument > cluster so

> > it was easy to

> > reach and fiddle with the adjustments. Then I > just

> > "exercised" the

> > air selection switch, causing the pump to kick > on

> > and adjusted the

> > high and low until there is always sufficient > vacuum

> > to operate the

> > air system but the pump does not run much.
> >

> > We're hitting the road on Saturday morning for > an

> > extended 5 week,

> > 5500 mile trip. Email me if you have questions > and

> > I'll try to get

> > to you in a few days.
> >

> > Dan & Ann

> > 1998 Allure #30180
> >
> >
>
>
>
>
>
>
>

> Yahoo! Domains ? Claim yours for only $14.70/year > >http://smallbusiness.promotions.yahoo.com/offer >[/quote]
Yahoo! Domains ? Claim yours for only $14.70/year http://smallbusiness.promotions.yahoo.com/offer
 

Re: Vacuum Pump Fix

Reply #4 –
Yahoo Message Number: 9860
Les, we'll be on the road. When you get the brand of the pump, run a google search and find the mfg and go to their site. They'll either have a tech assistance number or a dealer listing, or maybe both.

When you turn on the key, does the vacuum pump start up? How long does it run before it cuts out? Or does it just keep running? If it is shutting off, does it kick back on if you "exercise" the switch on the dash that switches between defrost, dash air & vent.
If not, I'd say your problem is in the control switch up under the dash (you'll need to check with CC for the location of yours, that's where mine is). I had this problem with my control switch--it was erratic and wouldn't kick the pump off before it unloaded automatically, so the pump ran continuously. The dash air worked but the pump ran all the time

This could be a vacuum leak as it almost sounds like you have vacuum to begin with but lose it over time. I'd check that first by testing the ability of the system to hold vacuum down at the pump.
Disconnect the service line and run a vacuum check. I did this crudely by running the pump to build up vacuum, pinching off the hose with a c clamp, waiting a couple of minutes to see if the system still had vacuum when I loosened the clamp.
If the system doesn't hold vacuum, you'll have to check the dash air actuator itself. Since I didn't have that problem, not sure where it is located. CC should know.
Dan

Allure #30180

Quote from: Les Knox\[br\
]