Home » Public Forums » GMCnet » Newbie question (first post) Viair or rebuild Dana?
| Newbie question (first post) Viair or rebuild Dana? [message #347797] |
Fri, 13 September 2019 22:30  |
Green machine
Messages: 184
Registered: July 2019
Location: North Vancouver BC
Karma: 5
|
Senior Member |
|
|
Hello all. Thanks you for allowing me to join.
As the title suggests, I'm debating between buying a new Viair 480c or rebuilding my old Dana. I will be upgrading to the 4 bag system as the stock bags are hooped.
TIA
Shawn Harris
North Vancouver,
Canada
1977 Palm Beach 403
|
|
|
|
| Re: [GMCnet] Newbie question (first post) Viair or rebuild Dana? [message #347799 is a reply to message #347797] |
Sat, 14 September 2019 00:23  |
 |
ljdavick
Messages: 3548
Registered: March 2007
Location: Fremont, CA
Karma: -3
|
Senior Member |
|
|
I’m right there too. I think I’ll just rely on my shut-off’s and schrader valves for the near term, but the Wireless Air 72000 from Airlift or the kit on Jim K’s site is in my future. Those both come with compressors, the wireless air has a 33% duty cycle and Jim K’s kit has a 100% duty cycle. If I had a windfall I’d just park the coach with Jim and say go at it!
My bags leak down over a couple of days so there’s a leak somewhere in the system. It might be fun to rebuild the solenoids yet the wireless air just seems so elegant.
Larry Davick
A Mystery Machine
1976(ish) Palm Beach
Fremont, CA
Howell EFI + EBL + Electronic Distributor
> On Sep 13, 2019, at 8:30 PM, s-m-h--- via Gmclist wrote:
>
> Hello all. Thanks you for allowing me to join.
>
> As the title suggests, I'm debating between buying a new Viair 480c or rebuilding my old Dana. I will be upgrading to the 4 bag system as the stock
> bags are hooped.
>
> TIA
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Larry Davick
A Mystery Machine
1976(ish) Palm Beach
Fremont, Ca
Howell EFI + EBL + Electronic Dizzy
|
|
|
|
| Re: Newbie question (first post) Viair or rebuild Dana? [message #347801 is a reply to message #347797] |
Sat, 14 September 2019 00:46 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
|
Senior Member |
|
|
Well, you are in the same position I was in 18 years ago. I attended a seminar at the GMCMI rally and one fellow, I believe it was John Clement, was having people bring in their Danas and repair / rebuild them in his class. It took about 2 hour. He had all of the parts and tested them at the end. I listened to all of the "experts" at the time and went and bought a replacement Vlair.
Now 18 years later that Vlair is in a box uninstalled somewhere in my coach. The rebuilt Dana has worked just fine for 18 years. Just fix all of your air leaks and if you leveling switches work that Dana will kick on once or twice a day while driving. If they do not work then the Dana will kick on once in 6 or 8 months.
It is all up to you, how much work you want to do, and how much you want to spend.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
|
|
|
|
| Re: Newbie question (first post) Viair or rebuild Dana? [message #347802 is a reply to message #347801] |
Sat, 14 September 2019 06:59 |
6cuda6
Messages: 975
Registered: June 2019
Karma: -6
|
Senior Member |
|
|
Im on the fence with you guys as well....i have my original DANA that i took out as it wouldnt pump air worth beans and i replaced it with a known good DANA....sadly it really doesnt do the job either.
I read all these stories about how that DANA does the job but either i have a monstros air leak (which i dont) or im not letting it run long enough to build pressure (i think over 25 minutes without air pressure on the gauge is not right).
I just dont see how a 1/8 inch line coming out of compressor can put enough volume into the system to build air effectively or reasonably quick enough.
Now to be fair maybe the line coming out of the compressor is supposed to be bigger but i cant find a size? Im using a 5psi crack pressure one way check valve so maybe its to strong,? (That is the recommended crack pressure btw)
So for me its a toss up....do i pull the DANA again and replace it with a Viair or try to make the DANA set up work......
Rich Mondor,
Brockville, ON
77 Hughes 2600
|
|
|
|
| Re: [GMCnet] Newbie question (first post) Viair or rebuild Dana? [message #347804 is a reply to message #347802] |
Sat, 14 September 2019 07:40 |
Richard Denney
Messages: 920
Registered: April 2010
Karma: 9
|
Senior Member |
|
|
What year is your coach? Is it a Power Level, Electro-Level, or
Electro-Level II system?
The Power Level system is entirely pneumatic except for the pump, and uses
a large (~a gallon) storage take mounted up front. The pump’s job is to
keep that tank at a pressure always higher that the bags. When the coach is
low, the leveling valve opens, feeding air from that tank to the bag. When
it is high, it dumps bag air to the outside. The pump has to run from time
to time even when you have no leaks, because it is not a closed system.
I rebuilt my Dana using a kit from Mr. Clement, and not too long after that
replaced it with a Viair. The Dana required much more time to pump that
tank up to the 125 psi required by the pressure switch.
25 minutes without a reading from a known-good pump, though, tells me
something is much more wrong than a tired pump or a slight leak somewhere.
It tells me the check valves aren’t letting air in, the pump/system is
plumbed incorrectly, the gauge is dead, or something significant like that.
Rick “who gets a read in a few seconds with any pump” Denney
On Sat, Sep 14, 2019 at 8:00 AM tonka6cuda6--- via Gmclist <
gmclist@list.gmcnet.org> wrote:
> Im on the fence with you guys as well....i have my original DANA that i
> took out as it wouldnt pump air worth beans and i replaced it with a known
> good DANA....sadly it really doesnt do the job either.
>
> I read all these stories about how that DANA does the job but either i
> have a monstros air leak (which i dont) or im not letting it run long
> enough to
> build pressure (i think over 25 minutes without air pressure on the gauge
> is not right).
>
> I just dont see how a 1/8 inch line coming out of compressor can put
> enough volume into the system to build air effectively or reasonably quick
> enough.
>
> Now to be fair maybe the line coming out of the compressor is supposed to
> be bigger but i cant find a size? Im using a 5psi crack pressure one way
> check valve so maybe its to strong,? (That is the recommended crack
> pressure btw)
>
> So for me its a toss up....do i pull the DANA again and replace it with a
> Viair or try to make the DANA set up work......
> --
> Rich Mondor,
>
> Brockville, ON
>
> 77 Hughes 2600
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
'73 X-Glacier 230 "Jaws"
Northern Virginia
Offlist email: rick at rickdenney dot com
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
|
|
|
|
| Re: [GMCnet] Newbie question (first post) Viair or rebuild Dana? [message #347806 is a reply to message #347804] |
Sat, 14 September 2019 08:24 |
6cuda6
Messages: 975
Registered: June 2019
Karma: -6
|
Senior Member |
|
|
Richard Denney wrote on Sat, 14 September 2019 08:40What year is your coach? Is it a Power Level, Electro-Level, or
Electro-Level II system?
The Power Level system is entirely pneumatic except for the pump, and uses
a large (~a gallon) storage take mounted up front. The pump's job is to
keep that tank at a pressure always higher that the bags. When the coach is
low, the leveling valve opens, feeding air from that tank to the bag. When
it is high, it dumps bag air to the outside. The pump has to run from time
to time even when you have no leaks, because it is not a closed system.
I rebuilt my Dana using a kit from Mr. Clement, and not too long after that
replaced it with a Viair. The Dana required much more time to pump that
tank up to the 125 psi required by the pressure switch.
25 minutes without a reading from a known-good pump, though, tells me
something is much more wrong than a tired pump or a slight leak somewhere.
It tells me the check valves aren't letting air in, the pump/system is
plumbed incorrectly, the gauge is dead, or something significant like that.
Rick "who gets a read in a few seconds with any pump" Denney
On Sat, Sep 14, 2019 at 8:00 AM tonka6cuda6--- via Gmclist <
gmclist@list.gmcnet.org> wrote:
> Im on the fence with you guys as well....i have my original DANA that i
> took out as it wouldnt pump air worth beans and i replaced it with a known
> good DANA....sadly it really doesnt do the job either.
>
> I read all these stories about how that DANA does the job but either i
> have a monstros air leak (which i dont) or im not letting it run long
> enough to
> build pressure (i think over 25 minutes without air pressure on the gauge
> is not right).
>
> I just dont see how a 1/8 inch line coming out of compressor can put
> enough volume into the system to build air effectively or reasonably quick
> enough.
>
> Now to be fair maybe the line coming out of the compressor is supposed to
> be bigger but i cant find a size? Im using a 5psi crack pressure one way
> check valve so maybe its to strong,? (That is the recommended crack
> pressure btw)
>
> So for me its a toss up....do i pull the DANA again and replace it with a
> Viair or try to make the DANA set up work......
> --
> Rich Mondor,
>
> Brockville, ON
>
> 77 Hughes 2600
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
'73 X-Glacier 230 "Jaws"
Northern Virginia
Offlist email: rick at rickdenney dot com
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Electro level 1 on mine....if i use my commercial air compressor everything works perfectly....the DANA just doesnt have the volume and/or the pressure. Im not and engineer, i am a mechanic that works with air systems every day.
As i said, something is amiss on mine....its either the compressor or/and the line size from the compressor to the tank because if i had to guess its not making over 5psi to crack the valve open....if thats the case it will never add air. (Plus even if it was there is 100psi on the other side of the check valve that it must overcome and its not doing that for sure)
Rich Mondor,
Brockville, ON
77 Hughes 2600
|
|
|
|
|
|
| Re: [GMCnet] Newbie question (first post) Viair or rebuild Dana? [message #347808 is a reply to message #347807] |
Sat, 14 September 2019 09:19 |
C Boyd
Messages: 2629
Registered: April 2006
Karma: 18
|
Senior Member |
|
|
I have repaired many air systems with good success. Thing is I have not found a silver bullet. They all had different issues. Air leaks were most common around the factory connectors, around the brake booster, on the back of the manual valves and the check valves being bad. The outside air tanks get pin holes. The solenoids get corroded and dirty. First thing I do is put a schrader valve in the tank and start looking for leaks. With a good check valve and electric switch and plugs and connectors, tank should hold air overnight. From there check air line connectors and solenoids then control valves. If the system is tight any good compressor will do the job. There are no short cuts. I do prefer the marked DOT push on connectors. They are easy and do not damage line or fitting when reused. I cut the plastic line with a sharp razor blade then fine sand paper to un-sharpen the cut edge and use a small amount of rubber lube or tire soap. Push hard to seat.
C. Boyd
76 Crestmont
East Tennessee
|
|
|
|
| Re: [GMCnet] Newbie question (first post) Viair or rebuild Dana? [message #347809 is a reply to message #347808] |
Sat, 14 September 2019 09:27 |
C Boyd
Messages: 2629
Registered: April 2006
Karma: 18
|
Senior Member |
|
|
Best prevention to keep a good system good is a water separator on tank and a drain valve on tank to keep water that naturally occurs when air is compressed. Big trucks that rely on air for suspension and brakes have a huge filter and spitter valve that spits the moisture out every time the compressor cycles.
C Boyd wrote on Sat, 14 September 2019 10:19I have repaired many air systems with good success. Thing is I have not found a silver bullet. They all had different issues. Air leaks were most common around the factory connectors, around the brake booster, on the back of the manual valves and the check valves being bad. The outside air tanks get pin holes. The solenoids get corroded and dirty. First thing I do is put a schrader valve in the tank and start looking for leaks. With a good check valve and electric switch and plugs and connectors, tank should hold air overnight. From there check air line connectors and solenoids then control valves. If the system is tight any good compressor will do the job. There are no short cuts. I do prefer the marked DOT push on connectors. They are easy and do not damage line or fitting when reused. I cut the plastic line with a sharp razor blade then fine sand paper to un-sharpen the cut edge and use a small amount of rubber lube or tire soap. Push hard to seat.
C. Boyd
76 Crestmont
East Tennessee
|
|
|
|
|
|
| Re: [GMCnet] Newbie question (first post) Viair or rebuild Dana? [message #347812 is a reply to message #347809] |
Sat, 14 September 2019 09:42 |
6cuda6
Messages: 975
Registered: June 2019
Karma: -6
|
Senior Member |
|
|
C Boyd wrote on Sat, 14 September 2019 10:27Best prevention to keep a good system good is a water separator on tank and a drain valve on tank to keep water that naturally occurs when air is compressed. Big trucks that rely on air for suspension and brakes have a huge filter and spitter valve that spits the moisture out every time the compressor cycles.
C Boyd wrote on Sat, 14 September 2019 10:19I have repaired many air systems with good success. Thing is I have not found a silver bullet. They all had different issues. Air leaks were most common around the factory connectors, around the brake booster, on the back of the manual valves and the check valves being bad. The outside air tanks get pin holes. The solenoids get corroded and dirty. First thing I do is put a schrader valve in the tank and start looking for leaks. With a good check valve and electric switch and plugs and connectors, tank should hold air overnight. From there check air line connectors and solenoids then control valves. If the system is tight any good compressor will do the job. There are no short cuts. I do prefer the marked DOT push on connectors. They are easy and do not damage line or fitting when reused. I cut the plastic line with a sharp razor blade then fine sand paper to un-sharpen the cut edge and use a small amount of rubber lube or tire soap. Push hard to seat.
Yup...mine holds air for a few weeks (actually the left side has a tiny leak that i need to find but it still take 2 weeks to drop half way).
Problem foe me is compressor.
Rich Mondor,
Brockville, ON
77 Hughes 2600
|
|
|
|
| Re: Newbie question (first post) Viair or rebuild Dana? [message #347815 is a reply to message #347797] |
Sat, 14 September 2019 10:06 |
C Boyd
Messages: 2629
Registered: April 2006
Karma: 18
|
Senior Member |
|
|
Sir, since your question was generalized it don't mean much in this case but normally it is an enormous help to those that are trying to diagnose your problems from our recliners if we know the year and model of your coach and is much more friendly if we know your name. Matt must be sleeping in today, probably from working on his coach to get ready for Mansfield. He is kinda our unofficial greeter and all round nice guy.
The GMC had 4 different air systems, one did not have dash controls for campsite leveling, one had manual dash valves for leveling with an external compressor and large air tank, next series had electric switches with solenoids and relays with a compressor and small storage tank inside a cabinet or under a bed or hid almost anywhere depending on model. The third and last series was electro level II and my favorite. It used same switches, relays, and a couple of the same 2 way solenoids as electro level I, but had a photocell electronic control in the fenderwell instead of the early type manual air in/dump valve. The electronic photo eye system controlled the ground to each of 2 independent compressors ( one for each side and no storage tank) that had the dump air solenoid valve in the head of the special compressor. The system was "hot 12 volt" anytime the key was on and the photocell controlled the ground to the relays that would control the solenoids and compressors to air up or dump air to lower.
Green machine wrote on Fri, 13 September 2019 23:30Hello all. Thanks you for allowing me to join.
As the title suggests, I'm debating between buying a new Viair 480c or rebuilding my old Dana. I will be upgrading to the 4 bag system as the stock bags are hooped.
TIA
C. Boyd
76 Crestmont
East Tennessee
|
|
|
|
| Re: Newbie question (first post) Viair or rebuild Dana? [message #347817 is a reply to message #347797] |
Sat, 14 September 2019 10:19 |
 |
Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
|
Senior Member |
|
|
Green,
Welcome to the group, family, cult, asylum.....
While a New Viair is more expensive, my Dana pump has done very well until it was damaged in a recent incident. I am not at all sure I would rebuild it again.
You found your way here and that is real good. You will also quickly learn that the coach connects you to an amazing community. We all want to see that you can enjoy both your coach itself and what it can do for you. To this end and as you seem to be working with us as the forum, please fill in a sigfile. You can do this easily by going up to <Control Panel/Account Settings> then choose <Preferences> and you will see the Signature Box. You can put in a name you like to be know by in person because you will meet other owners (that is a given and real names are good here), a short about the coach including an major mods - this is essential because there are many differences and some matter a lot - and finally a geographic reference, so far all we see is a Canadian flag, and you might have a brand new old friend near by that can be of some assistance.
This is an amazing community. These people are helping and supportive to a level you might not believe, but we all have stories (both ways). That level of support is not easy to find anywhere. As the only other community that provides that level of support and assistance that I know of is that of the watermen that are my world. For that very reason, I welcome new owners here with a paraphrase of how one would be greeted there. So,
May the Good Lord bless this coach and all those that set forth within her.
Welcome Green
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
|
|
|
|
| Re: Newbie question (first post) Viair or rebuild Dana? [message #347822 is a reply to message #347797] |
Sat, 14 September 2019 11:30 |
Green machine
Messages: 184
Registered: July 2019
Location: North Vancouver BC
Karma: 5
|
Senior Member |
|
|
Done and done! Thank you for the warm welcome!
I am leaning towards a rebuild based on what I'm hearing thus far. I like to keep things original as possible.
The coach is completely stock mechanically. The interior is completely gutted, a blank canvas. The idea is to begin with ensuring it is mechanically sound (including air ride)before I even think about the interior, generator etc.
Shawn Harris
North Vancouver,
Canada
1977 Palm Beach 403
|
|
|
|
|
|
|
|
|
|
| Re: [GMCnet] Newbie question (first post) Viair or rebuild Dana? [message #347833 is a reply to message #347831] |
Sat, 14 September 2019 14:45 |
C Boyd
Messages: 2629
Registered: April 2006
Karma: 18
|
Senior Member |
|
|
X 7525 75-76 maintenance manual rear suspension section 4 page 17 starts Dana dual cylinder compressor overhaul.
ljdavick wrote on Sat, 14 September 2019 14:19How in the world would you fix that??
> On Sep 14, 2019, at 10:38 AM, Ken Burton via Gmclist wrote:
>
> Did you check and set the timing between the two cylinders of the Dana pump? One must be all the way up while the other is all the way down.
> --
> Ken Burton - N9KB
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
C. Boyd
76 Crestmont
East Tennessee
|
|
|
|
|
|
|
|
Goto Forum:
Current Time: Fri Sep 20 19:28:48 CDT 2024
Total time taken to generate the page: 0.00870 seconds
|
GMCforum
Search
Help
Register
Login
Home
