Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
RV Trip Planning Discussions

Go Back   iRV2 Forums > MOTORHOME FORUMS > Class A Motorhome Discussions
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 05-13-2023, 08:54 PM   #1
Junior Member
 
Join Date: Jul 2017
Location: Seattle, Wa
Posts: 12
Air Dryer release valves

I going to replace my Midland Pure Air Plus canister and filter but I am having trouble locating the release lanyards. I found 1 up front right after the Condensing fan, pulled on it and nothing came out except a little whisp of air but I am fairly sure there is no air in the tanks (it has been sitting for 7 mos and some possible slow leak somewhere, as per normal).
I read here in previous posts that there is a lanyard or 2 in the rear? But I am not seeing any of this. I see a shrader valve just below the unit (see photo) and thinking this is the release valve for the air? Any insight would be appreciated. Cat 330 freightliner 2004.
Click image for larger version

Name:	air dryer valve.jpg
Views:	15
Size:	273.1 KB
ID:	392848
__________________
2005 Tropical 330 Cat Freightliner 37' & GMC Canyon Toad
skeeattle 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 05-13-2023, 10:10 PM   #2
Senior Member
 
Skip426's Avatar


 
Join Date: Apr 2011
Location: Powell River, B.C.
Posts: 31,311
The Schrader valve is in place to fill the tanks should the engine compressor fail and the system needs to be charged to raise the coach and release the park brake , before towing.
There are one way check valves that would prevent air from the tanks being released through this valve .

The lanyards on my coach had never been routed through the frame to the passenger side wheel well , and I found them still coiled up on the top of the front tanks . Never extended by the assembly line workers OR sought out and used by the two previous owners in 11 years.

Only two tanks in the front of the chassis , one has two chambers .
I'll see if I have a diagram that shows the drain valve locations .
You could pump the brakes a couple of dozen times to insure no air in either system.
__________________
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.
Skip426 is offline   Reply With Quote
Old 05-13-2023, 11:13 PM   #3
Senior Member
 
Join Date: Jul 2014
Posts: 35,349
The air dryer has no stored air in it once it purges, even hours or days later.

The only air that may be going to it will be on the small unloader line and only if the wet tank pressure is above about 90 psi.

As mentioned, all tanks will drain by pumping the brakes until the pedal feels slack.
twinboat is online now   Reply With Quote
Old 05-14-2023, 08:20 AM   #4
Junior Member
 
Join Date: Jul 2017
Location: Seattle, Wa
Posts: 12
Thanks, I will check the area out again. I pushed in the Schrader valve and nothing came out so I am pretty sure there is no pressure but I will pump the brakes as well.
__________________
2005 Tropical 330 Cat Freightliner 37' & GMC Canyon Toad
skeeattle is offline   Reply With Quote
Old 05-14-2023, 08:38 AM   #5
Senior Member
 
ArtJoyce's Avatar
 
Monaco Owners Club
Freightliner Owners Club
Holiday Rambler Owners Club
Join Date: Sep 2019
Location: Thornville, Ohio
Posts: 3,662
Quote:
Originally Posted by skeeattle View Post
Thanks, I will check the area out again. I pushed in the Schrader valve and nothing came out so I am pretty sure there is no pressure but I will pump the brakes as well.
I pushed Schrader valve on my MH and it did not release any air. Under closer inspection I found what I thought was a Schrader valve to be a rubber dummy. Not sure why the manufacture did this. you might have the same thing??
__________________
Art & Joyce
Thornville, OH
Kia Soul pushing a 36' DP Endeavor
ArtJoyce is offline   Reply With Quote
Old 05-14-2023, 09:34 AM   #6
Senior Member
 
Join Date: Jul 2014
Posts: 35,349
Quote:
Originally Posted by skeeattle View Post
Thanks, I will check the area out again. I pushed in the Schrader valve and nothing came out so I am pretty sure there is no pressure but I will pump the brakes as well.
That shreader valve has a check valve under it, it's the bigger fitting. No air will ever come out of it.
twinboat is online now   Reply With Quote
Reply

Tags
air, valve



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
RVA JII location of Manual Release valves AZ-Safari Monaco Owner's Forum 8 03-07-2021 12:17 PM
Black and Gray valves.....why not Ball valves? MuxedUpHRI Class A Motorhome Discussions 26 03-23-2017 06:06 PM
stiff sewer release valves IrieByTheSea Travel Trailer Discussion 9 05-06-2013 07:22 PM
Coachmen: Two Gray Water release valves DRosedale Forest River Owners Forum 2 06-04-2011 09:40 AM
Air dryer, What air dryer! Joec National RV Owner's Forum 3 07-17-2010 05:29 PM

» Featured Campgrounds

Reviews provided by


All times are GMT -6. The time now is 04:41 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.