Free 7 Day Trial RV GPS App RV Trip Planner Campground Reviews RV Maintenance Free 7 Day Trial ×
RV Trip Planning Discussions

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 02-25-2021, 02:08 PM   #1
Junior Member
 
Join Date: Sep 2019
Posts: 26
Slow air pressure build

Slow Air up..
Can I pick someone's brain on this thread? I have a '99 American Eagle that I purchased almost 2 years ago now and have had a problem with it building air pressure since day one..If I start it and just let it idle, it won't build up pressure unless I bring the rpm's up to 1500-1600 and even the it is very slow to build.
I hold these rpm's until it reaches around 65 psi and that noisy buzzer goes off! I can then idle it back down to normal idle speed and it will continue to build pressure to 130 psi..
Still at idle the pressure will SLOWLY decrease to around 110 at which it will increase normally back up to 130 psi..
My question is, where do I start to resolve this problem? I have replaced the drier dissicant and even had a mobile mechanic look at it and he replaced the governor(?)..it is mounted on the frame near the muffler and has a couple air lines mounted to it?? Do the dump valves have anything to do with the very slow air build and higher rpms's to get it to air up??


Thanks in advance for any info on this!

Newbie
VWtony 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 02-25-2021, 03:57 PM   #2
Senior Member
 
Join Date: Jul 2014
Posts: 26,834
If you pressure drops to 110 after reaching 130 and purging and your not using the brakes or moving, you have a leak.

There is no other reason for the air guages to drop.

Find a better mechanic.
twinboat is online now   Reply With Quote
Old 02-25-2021, 08:16 PM   #3
Junior Member
 
Join Date: Sep 2019
Posts: 26
Thanks for the response Twinboat..
I can understand I have a small leak when guages drift back down to 110 psi before compressor kicks in again and goes back up to 130 PSI, so I'll have to find that leak (can't hear it so it will be hard to find, I suppose).

Any idea what may be causing my main problem of having to increase engine speed so much to get it to even start airing up??
VWtony is offline   Reply With Quote
Old 02-25-2021, 11:56 PM   #4
Senior Member
 
Join Date: Jul 2014
Posts: 26,834
Quote:
Originally Posted by VWtony View Post
Thanks for the response Twinboat..
I can understand I have a small leak when guages drift back down to 110 psi before compressor kicks in again and goes back up to 130 PSI, so I'll have to find that leak (can't hear it so it will be hard to find, I suppose).

Any idea what may be causing my main problem of having to increase engine speed so much to get it to even start airing up??
You may also have a leak in the lines from the compressor to the air dryer. They are hard to hear due to the engine noise.

They would only leak while it's running, due to check valves in the system after the dryer.
twinboat is online now   Reply With Quote
Old 02-26-2021, 05:34 AM   #5
Senior Member
 
Join Date: Sep 2016
Location: Sarasota, FL
Posts: 4,491
Make yourself some ramps like these and then get on a creeper with a spray bottle of soapy water and spray anything that has a hose going into it or looks like an air tank.


Look at moisture ejectors and see if they are leaking




Also check ride height valves
__________________
Rick and Larrie Dee
1997 40' Newmar London Aire DP CTA 8.3 (Mechanical) 325 Spartan MM
Bringing her back to her glory.
'08 Jeep GC Overland.
RKins is offline   Reply With Quote
Old 02-26-2021, 06:05 AM   #6
Senior Member
 
KanzKran's Avatar


 
Join Date: Sep 2018
Posts: 1,481
Quote:
Originally Posted by VWtony View Post
Any idea what may be causing my main problem of having to increase engine speed so much to get it to even start airing up??
Sounds like either a worn compressor, or bad check (reed) valve in the compressor's head or body that are sealing tighter at higher pressure.
__________________
Tom & Jeri
2018 Coachmen Galleria 24T Li3
KanzKran is offline   Reply With Quote
Old 02-26-2021, 12:09 PM   #7
Senior Member
 
96 Wideglide's Avatar
 
Holiday Rambler Owners Club
Join Date: Aug 2010
Posts: 7,346
Quote:
Originally Posted by VWtony View Post

Any idea what may be causing my main problem of having to increase engine speed so much to get it to even start airing up??
The faster the engine is turning, the faster the compressor is spinning.

It's taking that many rpm's to overcome the large leak you have somewhere in your air system.
__________________
Ben & Sharon
2008 43' Holiday Rambler Scepter PDQ
96 Wideglide is offline   Reply With Quote
Old 02-26-2021, 01:37 PM   #8
Senior Member
 
Tha_Rooster's Avatar
 
Join Date: Aug 2008
Location: Georgia
Posts: 6,586
Quote:
Originally Posted by 96 Wideglide View Post
The faster the engine is turning, the faster the compressor is spinning.



It's taking that many rpm's to overcome the large leak you have somewhere in your air system.


Which in my opinion is a high idle rpm for a diesel.
__________________
2007 Fleetwood Revolution LE 40V
Tha_Rooster is offline   Reply With Quote
Old 02-27-2021, 01:56 PM   #9
Moderator Emeritus
 
Gary RVRoamer's Avatar


 
Join Date: Jan 2000
Location: Silver Springs, FL. USA
Posts: 23,981
Has the air dryer ever been serviced? Slow pressure build is a common sign of a clogged air dryer on the compressor.
__________________
Gary Brinck
Former owner of 2004 American Tradition and several other RVs
Home is in the Ocala Nat'l Forest near Ocala, FL
Summers in Black Mountain, NC
Gary RVRoamer is offline   Reply With Quote
Old 02-27-2021, 03:18 PM   #10
Senior Member
 
Join Date: Jul 2014
Posts: 26,834
Quote:
Originally Posted by Gary RVRoamer View Post
Has the air dryer ever been serviced? Slow pressure build is a common sign of a clogged air dryer on the compressor.
He said in his opening post it was.
twinboat is online now   Reply With Quote
Old 02-27-2021, 09:44 PM   #11
Senior Member
 
Ray,IN's Avatar
 
Join Date: Aug 2001
Location: North America somewhere
Posts: 22,058
Yes the air dump valve can be leaking, the only way to determine that is do what RKins recommended.
__________________
2000 Winnebago Ultimate Freedom USQ40JD, ISC 8.3 Cummins 350, Spartan MM Chassis. USA IN 1SG 11B5MX,Infantry retired;Good Sam Life member,FMCA." My fellow Americans, ask not what your country can do for you, ask what you can do for your country. John F. Kennedy
Ray,IN is offline   Reply With Quote
Old 02-28-2021, 08:58 AM   #12
Senior Member
 
Piros1's Avatar
 
Join Date: Dec 2015
Location: Dittmer, MO 63023
Posts: 770
As others have said you most likely have a leak, I would start as Rkins suggested. Get your rig up in the air, get a squirt bottle of soapy water, a creeper, and a pair of safety glasses and start spraying every line, fitting, and component related to the air system starting at the compressor all the way to the brake system. Since you don’t hear it when walking around it you probably have several leaks. I personally would go front to back and back to front to be sure I hit everything. Then document what is leaking with photos and start fixing. My second thought is you may have a weak/worn out compressor along with the air leaks adding to the slow air build. They do wear out and fail.

You did not mention what coach you have or I missed it, that would be could if you share this info in your post or add to your signature page.
__________________
2005 CC Affinity 770, 2006 Jeep TJ
2015 Newmar Essex 4553
Piros1 is offline   Reply With Quote
Old 02-28-2021, 07:22 PM   #13
Senior Member
 
Ray,IN's Avatar
 
Join Date: Aug 2001
Location: North America somewhere
Posts: 22,058
Quote:
Originally Posted by Piros1 View Post
As others have said you most likely have a leak, I would start as Rkins suggested. Get your rig up in the air, get a squirt bottle of soapy water, a creeper, and a pair of safety glasses and start spraying every line, fitting, and component related to the air system starting at the compressor all the way to the brake system. Since you donít hear it when walking around it you probably have several leaks. I personally would go front to back and back to front to be sure I hit everything. Then document what is leaking with photos and start fixing. My second thought is you may have a weak/worn out compressor along with the air leaks adding to the slow air build. They do wear out and fail.

You did not mention what coach you have or I missed it, that would be could if you share this info in your post or add to your signature page.
His profile says he has a 40' American Eagle. The air compressor should be good for 100,000 miles.
__________________
2000 Winnebago Ultimate Freedom USQ40JD, ISC 8.3 Cummins 350, Spartan MM Chassis. USA IN 1SG 11B5MX,Infantry retired;Good Sam Life member,FMCA." My fellow Americans, ask not what your country can do for you, ask what you can do for your country. John F. Kennedy
Ray,IN is offline   Reply With Quote
Old 02-28-2021, 11:00 PM   #14
Senior Member
 
Piros1's Avatar
 
Join Date: Dec 2015
Location: Dittmer, MO 63023
Posts: 770
Quote:
Originally Posted by Ray,IN View Post
His profile says he has a 40' American Eagle. The air compressor should be good for 100,000 miles.
I must be blind I didnít see it thanks for letting me know. Typically I agree that the compressor should last 100,000 or more. We get 200,000-300,000 or more in my fleet of over 35 vehicles and 20 or so are air brake trucks on average but I have seen them fail in less than 50,000. I have also seen them prematurely get week and have difficulty supplying enough air especially with significant air leaks.
__________________
2005 CC Affinity 770, 2006 Jeep TJ
2015 Newmar Essex 4553
Piros1 is offline   Reply With Quote
Reply

Tags
air



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
Excessive air pressure build up/brakes/air ride Hotrod2526 Freightliner Motorhome Chassis Forum 13 03-29-2019 05:50 AM
iRV2 running slow/back arrow slow charles tuit Forum 101 | Announcements | Member Forum Concerns 9 03-14-2016 12:54 PM
New Build date just received, 1mo to build??? albawsadv Tiffin Owner's Forum 9 01-17-2015 03:02 PM
Slow slow HP laptop wagonmaster2 Technology: Internet, TV, Satellite, Cell Phones, etc. 18 11-10-2011 09:22 AM
slow to build pressure Rudolph MH-General Discussions & Problems 3 04-21-2009 04:26 PM


All times are GMT -6. The time now is 07:38 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.