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chasing air leaks on 2007
#1

hi all,  

i am posting this on winegrowers 2007 coach 1202

bob and sandy came to my place and we had their beautiful 4 slide 2007 newell in my shop for the last 2 weeks.  they lived in the coach as it is quite nice inside the shop and they had full access to the bathroom and shower in my mancave.  

i will try and post simple versions of what we did and learned.  that said i will say bob had to do alot of the hard work as i am waiting to get a knee replaced soon.  i kinda hobble around    i think i probably have the only garage with a lazy boy right where we are working....ha

problem 1.     drivers side rear drops all the way overnight.   using my whisper sniffer and alot of kids bubbles in a spray bottle we found two things.   the zf suspension with steerable tag has two airbags on the drive axle and 1 on the tag.  the drive bag between the axles fitting on top of the bag was leaking.   we replaced it.   then we had to hunt for other leaks.   we used my pressure test jig to isolate each section.  we tested each airbag separately and they all held air with no leaks.   the idea is to isolate each section and eliminate it for leaks.  

the airbags for the drive axle are totally easy to get at.  can change them without taking a wheel off easy.  the one in front of the drive axle when we deflated it, separated from the top mounting plate.  the mounting plate is just setting with a bead like seal on the top of the bag.  to get it back up we took the bottom nut off that holds the bottom of the bag on, greased up the top plate and with air applied pushed the bag up, then aimed the bottom mounting plate back into the hole and walla....got it on.  we got quite good at it i must say.  

we tested from the six pack to the airbags....still a leak.  the zf suspension has traction control that puts air in or takes air out of the bags on the rear.  there is a traction control valve on each side in the rear.  the one on the drivers side was leaking.  they are unobtanium.  called bendix, and there was non in north america.  fortunately newell had two so bob had them overnighted (took 4 days).  the valves are located near the tag up on a frame rail.    fast forward to last nite and it held air up all night and no dropping.  so we fixed that.  

problem 2.  passenger side rear ride height valve was escaping air out the exhaust port all the time even when we were NOT in travel mode.  a short primer on ride height valves....avail elsewhere on the forum as well.      2 air lines on the rhv.   one is constant air in.  always air there if there is air in the system.  the line on the rhv goes directly to the six pack.  that line connects directly to the rear air bags on that side.   if the rhv calls for air (in travel mode and coach is low on that side) then in travel mode the travel solenoids are engergized and open and the air flows from the air source on the rhv to the six pack and then directly to the 3 airbags on that rear side.   if the rhv calls for air to be released because the coach is high on that side, then the bags escape air through the six pack to the rhv and exhausts out the bottom.  a note on valid leveling system is that travel mode is called select on the six pack.  

the rhv is totally accessible in front of the drive wheels on the side of the coach unlike our older ones.  

only way for air to be escaping out the exhaust port is the valve is broken, or the travel solenoid is open some or a lot.  

i had a spare rhv so we change that and tested the old one.  it was working perfectly.  so it had to be the travel solenoid (note to self....should have tried that first).  the valid six packs are different than hwh.  the valves have no valve body with orfice.  the orfice is in the six pack itself.  so you take the coil off and then take the stem out of the six pack like you would take the stem out of the valve body that on the hwh ones.   use the same spanner wrench as for the hwh valve.    bob got the passenger side travel (select) valve stem out and the orfice and plunger was all gunked up with debris.   cleaned it up, put it back in and now no flow out of the rhv.  

i learned a ton about the braking system on the 07.  it is quite different than the one on my 02.   i will write that up separately.  we thought we might have had a problem with a ppv valve on bobs, but that ended up not being the case.  

problem 3

120v compressor comes on every 5-10 minutes.   the 07 has twin 120v compressors.  you can choose to use one or the other.  they are backups to each other.  there is no 12v compressor like my 02.  

we found a bad fitting on a distribution block on top of the front six pack behind the headlight.  not much room up in their on this year coach.  we found a bad fitting on the 120v compressor distribution block.   

i found a leak on the regulator valve on the bode air entrance door.  it is behind the laminate cover.   it is a pricey little piece of plastic at 147 dollars from bode.  

we went over every square inch of the coach that we could find air fittings.  inside and out.  the only things that are air powered are the airbags for the front mounted genny, the air horns, the entrance door and the two pocket doors.  the potties are electric and so is the step cover.     the supply air drops pretty quickly.

we took off each air line on the accessory tank in the rear and pressurized them separately with my test rig.  there was one quarter inch line (all the rest were 3/8) that was leaking down fairly fast.  we thought this was the quarter inch line from the front compressor but that was not the case.  the quarter inch line from the compressor goes somewhere and converts to 3/8 then goes to the level tank and then a small line from the level tank to the accessory tank.  

using my whisper sniffer and quarts of kids bubbles led to no further discoveries.  so that mystery is for another time.  

all of this could have been days shorter with an air system schematic from newell.  but to no avail.  

i am sure i missed alot, so bob please chime in.  i know you replaced more fittings than i have mentions and you are the one who really got dirty.  good think is he spent so much time scooting around on my floor that it is pretty clean now....ha

bob is a delight to work with and it was fun having him here.  

thats all for now.  

tom


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2002 45'8" Newell Coach 608  Series 60 DDEC4/Allison World 6 Speed HD4000MH

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#2

Nice write up Tom. You make this sound logical in your trouble shooting approach. I wish I was there working with you guys as it is much less stressful working on someone else's stuff.
I hope your knee work turns out good. I'm getting a second hip replaced in a couple of weeks.

Hank & Natalie Bensley
2001 Double Slide #586. 
2021 Cherokee Trailhawk Toad
We've been RV owners since 2002.
Port Orange, FL. Soon we will travel full time for "a while" Smile
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#3

i hope bob adds his comments to this. and we spent days doing this, not hours. it was a slow meticulous progress.

and we both learned a ton

tom

2002 45'8" Newell Coach 608  Series 60 DDEC4/Allison World 6 Speed HD4000MH

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#4

i did not put this in my original post but is very important.....

for virtually all of this, we had bobs coach up on 4 22 ton jackstands. do not get underneath without some type of cribbing.

tom

2002 45'8" Newell Coach 608  Series 60 DDEC4/Allison World 6 Speed HD4000MH

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#5

btw, thats my 02 on the right, bobs 07 on the left and clarkes 82 parked at one of my 50 amp full hookup spots next to the shop. hey, i even have soft water hookups for visitors

tom

2002 45'8" Newell Coach 608  Series 60 DDEC4/Allison World 6 Speed HD4000MH

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#6

Does Bob's coach have air ride seats up front?

Forest & Cindy Olivier
1987 log cabin
2011 Roadtrek C210P
PO 1999 Foretravel 36'
1998 Newell 45' #486 

1993 Newell 39' #337 
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#7

i didnt put that down but we checked them. plus there was a shutoff valve at the drivers seat

tom

2002 45'8" Newell Coach 608  Series 60 DDEC4/Allison World 6 Speed HD4000MH

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#8

So what was the outcome....did you improve the compressor cycle time?

Bill Johnson
Birmingham, Alabama
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#9

after all of that......no it is still a mystery. i called and talked to karl blade this morning and asked if there were generic air plumbing schematics for that vintage and he said there was not.

bob and i talked this morning about some things for him to try to look at now that he is back home.

we fixed lots of leaks, but the one quarter inch line going from rear to back is leaking down and we have not as of yet found where it goes.

seems like it should be simple, but it was not.

tom

2002 45'8" Newell Coach 608  Series 60 DDEC4/Allison World 6 Speed HD4000MH

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#10

Where to start?
Those of you who know Tom and have been to his place are aware of not only his talent but also his capabilities and persistence.    

  • Orderly examination of the air lines was the most rewarding method to search for the leaks.
  • Isolation of the air lines using the 2 gauge air line system shown in Tom's post was helpful.
  • Steve and Richard's air system maintenance YouTube videos are a good source of information to better understand how to test.
  • [/url][url=https://www.youtube.com/results?search_query=newell+air+system+maintenance]Newell Air System Maintenance YouTube videos
  • Understanding the system is essential
  • Cutting zip ties to expose individual contents of the air line bundles was helpful 
  • Good hearing is essential, I don't have it so some method of amplification was useful.  Tom had good hearing plus a Whisper ultrasound unit and a stethoscope
  • A supply of 1/4" and 3/8" compression and push to connect fittings with both 1/4" and 3/8" NPTF threads, both straight and 90 degree, along with unions and plugs are needed.
  • Some fittings require swivel connections due to locations and may only be available in push to connect style.
  • If testing larger brake lines even larger fittings will be required. 
  • A washing machine for grease and grime covered clothes is helpful
  • If you can fix a mop to your back you'll have a very clean floor when you're done Big Grin

Sandy and Bob McBratney
Previous owners of 2007 Newell #1202  "Boomer" 
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