Go Back   iRV2 Forums > MOTORHOME FORUMS > MH-General Discussions & Problems
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 04-19-2015, 07:36 PM   #1
Senior Member
 
Join Date: May 2002
Location: Champion, PA.
Posts: 337
Air pump on firewall?

Noticed an intermittent buzzing noise coming from outside the firewall while driving my motorhome yesterday. Extended the generator and found that the noise was coming from a small pump mounted directly above the center of the generator on the firewall. The pump is connected to a round container about the size of a softball via rubber hose. Any ideas what this is and why is keeps cycling on and off?
__________________

__________________
2004 Thor Mandalay 38B
Stump Jumper is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 04-19-2015, 07:42 PM   #2
Senior Member
 
Join Date: May 2002
Location: Champion, PA.
Posts: 337
Forgot to mention that it is an air pump of some sort, not a fluid pump.
__________________

__________________
2004 Thor Mandalay 38B
Stump Jumper is offline   Reply With Quote
Old 04-19-2015, 07:45 PM   #3
Senior Member
 
Join Date: Jul 2007
Posts: 678
Probably a vacuum pump used by the dash HVAC controls. If it keeps running you may have a vacuum leak at one of the connections.
__________________
Pete - Full Timing
2000 Country Coach Magna 40', CAT C10, #5892
2006 Jeep Liberty
phays is online now   Reply With Quote
Old 04-19-2015, 08:12 PM   #4
Senior Member
 
Join Date: May 2002
Location: Champion, PA.
Posts: 337
That is kind of what I thought. There is an open connector on the passenger side of the pump. When I put my finger over the connector, I can feel it pulling vacuum and the cycling of the pump slows down, but still continues. The strange thing is that the connector does not look like there was ever a hose connected to it and there is no loose hose hanging near it. Any ideas?
__________________
2004 Thor Mandalay 38B
Stump Jumper is offline   Reply With Quote
Old 04-20-2015, 06:14 AM   #5
Senior Member
 
Join Date: Jul 2007
Posts: 678
I suggest you post your question in the Thor Owners Forum. Perhaps someone there has been through this before.
__________________
Pete - Full Timing
2000 Country Coach Magna 40', CAT C10, #5892
2006 Jeep Liberty
phays is online now   Reply With Quote
Old 04-20-2015, 04:25 PM   #6
Senior Member
 
wa8yxm's Avatar
 
Damon Owners Club
Workhorse Chassis Owner
Join Date: Mar 2009
Posts: 22,816
Quote:
Originally Posted by phays View Post
Probably a vacuum pump used by the dash HVAC controls. If it keeps running you may have a vacuum leak at one of the connections.
I used to have a car (Well van) that had low-vacuum issues and installed a vacuum canister.. You described it perfectly (a round container about the size of a softball )

Thus I support the Vacuum pump theory.. Diesels need them.. Front Engine Gassers .. the engine sucks (I am actually being serious).
__________________
Home is where I park it!
wa8yxm is offline   Reply With Quote
Old 04-20-2015, 10:24 PM   #7
Senior Member
 
FIRE UP's Avatar


 
Join Date: Dec 2009
Location: Out there, somewhere
Posts: 5,279
Quote:
Originally Posted by Stump Jumper View Post
Noticed an intermittent buzzing noise coming from outside the firewall while driving my motorhome yesterday. Extended the generator and found that the noise was coming from a small pump mounted directly above the center of the generator on the firewall. The pump is connected to a round container about the size of a softball via rubber hose. Any ideas what this is and why is keeps cycling on and off?
Stump Jumper,
As has been stated, its' a vacuum pump. Diesels primarily don't supply or, create I should say, any vacuum like a gas engine does. And, as you most likely know, there's still a need for vacuum operated/controlled components on many of todays autos/trucks/cars/motor homes/space ships/submarines, ooops got carried away. Anyway, since vacuum control is an easy way to control doors and ducts for A/C and heated air, you need VACUUM to do that.

Well, that little pump you're hearing is your vacuum pump. But, kind of like an air compressor builds pressure in an air tank, to be used at a later date for multiple reasons, vacuum needs to be stored for much of the same principles. Hence, your little "Soft ball" sized sphere. On many cars and trucks of yesteryear, there appeared to be black painted "tomato juice cans", "Tuna cans" and all kinds of "can" looking vacuum storage containers.

Finally, most manufacturers just resorted to the use of those little spheres as vacuum storage containers. Hope this helps some.
Scott
__________________
2004 ITASCA HORIZON 36GD, 2011 GMC Sierra 1500 4x4 Toad '08 GL 1800 Gold Wing
Retired-29.5 yrs, SDFD, Ham - KI6OND
Me, Karla and the Sophie character, (mini Schnauzer)
FIRE UP is offline   Reply With Quote
Old 04-21-2015, 08:54 AM   #8
Senior Member
 
jacwjames's Avatar
 
Monaco Owners Club
Join Date: Jun 2014
Posts: 4,597
Stump Jumper
Do the vent controls for your AC & Heat work, are you able to change the type of delivery from defrost to circulate or any other location.

I would take a close look at the loose hose you've found and see if could have been connected to a hard to see location.

I have a vacuum generator on the firewall of my coach. I had been doing some work on the generator, installing remote start, and accidently dislodged a hose. When we got ready to leave I could hear the vacuum generator clicking and finally found a hose dislodged.
__________________
Jim J
2002 Monaco Windsor 38 PKD
2005 Jeep Grand Cherokee w/5.7 Hemi
jacwjames is offline   Reply With Quote
Old 04-21-2015, 10:21 AM   #9
Senior Member
 
Join Date: May 2002
Location: Champion, PA.
Posts: 337
In response to your question, the heater controls on my dash do not work. As a matter of fact, the blower control does not work either. I just bought this motorhome last Fall and did not have the chance to use the dash controls. I am starting to wonder if there wasn't a problem with it that was not disclosed. I will try to track down what I assume is an electrical problem with the blower and will check all hoses and connections on the vacuum system as well. Would this vacuum system service anything other than the heater controls?
__________________
2004 Thor Mandalay 38B
Stump Jumper is offline   Reply With Quote
Old 04-21-2015, 10:45 AM   #10
Senior Member
 
cbeierl's Avatar
 
Winnebago Owners Club
Freightliner Owners Club
Join Date: Aug 2005
Location: Nashua, NH
Posts: 2,002
Here are a couple of earlier threads with pics, etc. that might help: Vacuum Pump Failure and vacuum line leak anyone?
__________________
Chris Beierl

2005 Winnebago Vectra 36RD
cbeierl is online now   Reply With Quote
Old 04-22-2015, 07:43 PM   #11
Registered User
 
Join Date: Feb 2013
Posts: 472
Doubtful
__________________

__________________
Fl_Richard is offline   Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Using the air in my brake system to pump up tires gpete1961 Country Coach Owners Forum 15 03-31-2015 04:25 PM
Air suspension not airing up level. Cuylerpilot Roadmaster Motorhome Chassis Forum 6 03-07-2015 01:03 AM
New lift pump for my 2001 5.9 ISB sknight Cummins Engines 19 09-03-2014 09:09 PM
Water pump problem? Spk64 Newmar Owner's Forum 24 08-21-2014 08:52 PM
Air Cleaner Air Intake/Pick Up Dutch Star Don Newmar Owner's Forum 47 04-21-2014 09:20 PM

» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 06:38 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.