View Full Version : Air leaks in my 1987.

06-14-2009, 05:23 AM
Hello, Jennifer here again. I've moved from my electrical chasing(still chasing) to air leak chasing. I charged up the air today to do a test on how long the air pressure would last. In 25 to 30 minutes the pressure went from 120 psi to just below 60 psi. Both the brake and service air pressure went down at exactly the same rate. Not good. I grabbed my spray bottle and went directly to the solenoids in the drivers side front compartment and started spraying. I found 2 leaks on the fittings( 90 degree elbows.) These fittings are not brass they seem to be come sort of ceramic?? material. The actual fittings are leaking as are the air lines going into those fittings. I also heard an air leak under the accelerator pedal. How do I access that? Is it possible to remove the carpeted plywood wall that is in front of the panel? Any clues on how to do that? On each air line is either a white ring or a green ring. What do these mean? I went to the rear of the coach and sprayed down all the fittings and solenoids in the passenger side of the engine compartment. Found a leak there as well. Those 90 degree elbows are brass. I have no clue where the compressor is on this coach. It's a bit daunting to crawl around under this coach but I'll do if need be. I think I need to replace the fittings. How do the fittings attach to the airlines? It got dark so I haven't taken one apart yet. Any help would be greatly appreciated!

Concerning my generator issues...Does anyone know how long it will take 6 deep cycle batteries to charge on with a 40 amp output battery charger? I'm waiting for the batteries to fully charge before I load test them. I'm plugged into 50 amps right now. With wrenches, soap and guts in hand....Jennifer

06-14-2009, 07:59 AM
Jennifer, you have a number of issues with your air system. First, the brake air pressure leaking down at the same rate as your supply air means that the check valves to the brake air tanks are not working. This is a serious problem and should be fixed as soon as possible. A truck repair facility that works on semi's can do this as they are the same check valves that semi's use.

Please don't get under the coach without cribbing in place to prevent the coach from dropping on you. Each location that is leaking should be addressed. Many of the fittings are press to remove fittings. Press in on the air line and the end of the fitting then pull the air line out of the fitting.

There should be an engine mounted air compressor on the rear of the engine (toward the front of the coach). You may also have a 120 volt air compressor. It could be mounted in a number of places. In my coach it is in the right front bay. On Tom's coach it is in the left front bay. On some they are with the generator in the front.

You many have an air throttle. If you don't the leak you heard from near the throttle could have been coming from the air brake valve under the dash. On min coach, the panel behind the brake and throttle is removed by pulling firmly outward at the top on the panel near the right side of the panel. I think that in some of the early 80's coaches, there were some screws holding the panel on.

If the six pack (leveling solenoids) fittings are leaking, it may be necessary to replace the elbow fittings with metal elbows.

Richard and Rhonda
06-14-2009, 11:42 AM

As you have noticed, there are MANY airlines in the Newell. Most of them were assembled using the quick press style of connection, in that all that is necessary is to push the air line into the fitting and voila it magically seals. Over time the collet inside those fittings causes the plastic of the air line to compress, and it eventually will start to leak. Sometimes snipping about a 1/4 off the airline and putting it back in will stop the leak.

When I find leaks I have been in the practice of replacing the quick fitting with a traditional style compression fitting.

To be technically correct, DOT fittings should be used. I always use the DOT rated fittings when I replace one in the braking system. I am not quite so persnickety on the other systems and confess to using fittings from Lowes and HD.

If you don't have a convenient truck supply place, you can order the DOT compression fittings from McMaster Carr. They are not much more expensive than the standard compression fitting. Most of us nuts just lay in a supply of all manner of the fittings, because like you we are always searching for lost air. When you are stocking up on air system supplies, you might also obtain some 1/4 and 3/8 DOT air line. It is important to use the DOT airline and not the home supply stuff when replacing an airline.

Any progress with the generator??

06-14-2009, 04:20 PM

i had exactly the same problem on the brake and supply going up and down together. replaced the check valves on both tanks upfront. the valves were 22 bucks apiece. that is something i would have done at a shop. and i do alot of stuff myself.

my carpeted panels at my feet in the drivers area are not like michaels. mine have philips screws in them embedded in the carpet that have to be removed.

for some reason i didnt think that they had air throttles on that year, but i could easily be wrong. as michael said, there are several air lines under there. ones for the air brake, for the parking brake, and a number of others that just run through there.

we have all done what you are doing. replacing fittings one at a time. i too keep a bag of them in the coach. as well as some pieces of dot line.

eventually you will find most of the leaks. i know wally went through and changed essentially every fitting and valve and his stays aired up for almost forever.

we have also most of us replaced fittings and or solenoids on the leveling system. there are lots of posts on that here. if you have all of them working, that is quite amazing.

i put in a new 11ov compressor. i put pictures of mine below so you know what you are looking for. they all seem to have exactly the same one for these years. the checkvalve on the compressor is another potential source of leak as well.

i put a new pressure switch and all new lines and hardward on mine when i did it.



06-14-2009, 08:03 PM
Thanks, all your suggestions, and the info is invaluable and I will make an appt Monday to have the check valves replaced. I do not have another compressor. The one on the engine is it. Perhaps I should put one on board. Any clues as to what the green and white rings on the airlines signify? You guys are the best! Thanks for sharing the results of your own learning curves. I'll be back with more. Today it's air leaks, battery checking and generator fixing day! Jennifer

06-14-2009, 08:16 PM
i am suprised you dont have a 110v compressor. there is no switch on the dash that says compressor?

as for the colored rings, every mfgr has their own coding system. i wouldnt pay any attention to it. it is as simple as DOT and what size, angle and swivel or not as well as compression or quick release.


Wally Arntzen
06-14-2009, 08:17 PM
Jennifer, my 88 is probably is a duplicate of yours as far as the air system goes. When I got my coach the leaking was terrible so don,t think you can't fix it. I found leaks in the welds of two of my large tanks and the small tank for the toilet, check valves and air switches not working or leaking.
After spending days with a friend of mine who runs a bus repair facility we agreed to bite the bullet and just do it all.
I replaced the three tanks which I got from Newell, check valves on all tanks and the 110 air pump, air switches for the wipers, generator access door, step cover and both windshield wiper motors which air operated in my coach. I changed the flush handle on the toilet which is air operated and replaced the air preasure control valves at the toilet, tag axel and 110 generator.
We did not fine one leak in an air line. All of the problems were tanks, valves and switches.

At this time my wife and I are fulltimers and live in the coach. My air pump goes on an average of 2 times in 24 hours with the two of using everything without restricting our usage.

I have been advised that the biggest contributer to our problems with the older coaches is that we do not drain the air out of our tanks enough and the moisture contaminates the valves and switches which causes them to fail over time.

I may be a little wierd but I change things just because they are old and may go bad. I do not like to just let go untill something fails and then fix it. And even being a maintanice maniac I still have problems that need attention but they are few and far between.

These coaches are just like little kids they need a lot of attention it if they get it they very comfortable and kind to us.
Good luck, Wally

06-14-2009, 08:52 PM
Thanks again...I do not have a switch on my dash that says compressor. Wish I did. My toilet is not air actuated. (original was replaced )My throttle is air actuated. I pulled one of the air lines in the leveling system up front and the "plastic" elbow is cracked. I would feel better if these were brass. I need to get some of those elbows. I live 25 miles out of Missoula. Would a truck repair place have them or are they special order. Richard suggested McMaster Carr. I'm going to go back to crawling around this sweet beast. I'll be back, Jennifer

Wally Arntzen
06-14-2009, 08:55 PM
Jennifer, I forgot to add that we also rebuilt the air switch on transmission that allows it to shift and the controls at the bottom of the accelerator pedal that allows your fuel system to function.
The tanks were not very pricey and as Tom has indicated neither were the check valves The costely ones were the air switches, wiper motors, etc..
If you have the abilities of help from a friend or two it is not as big of a deal as it looks.
If you have to have it done by a garage you are looking a very large amount of money on labor as well as mark up on parts.

06-14-2009, 10:04 PM
I pulled the wall out front from in front of my feet and found an enormous amount of 22 year old dust and cobwebs. I also found a black plastic round ball mounted to the fire wall with a few small hoses going in and out of it. Any ideas what that might be? A filter of some sort?

The air lines going to the throttle and the brake must be coming up through the floor. Gave me a good chance to look around, vacuum and see what what and who's where. I pulled 2 of the 3 airlines with the plastic collet and all collets are cracked. The third collet is hanging right onto that air line and I may have to cut it. Apparently, these solenoids are for the supply air. I will replace all 3 collets and line ends and will have 3 out of many replaced. Are the compression fittings hard to install? Do I need any special tools to install them? Again, I am grateful, Jennifer

Off to the check batteries. All batteries had 3 definite floating balls with most the 4th ball hanging around the middle of the glass. If the batteries are shot, will all 4 balls float completely? I want to load test the batteries them but they have to be fully charged.

Wally Arntzen
06-14-2009, 10:19 PM
Jennifer, your right, it is much better to use brass than the plastic. Compression fittings are very easy to use all you need is two wrenches normally 7/16, 1/2 or 5/8 depending on the size of the line. On mine the air lines are from 1/4 all the way to 5/8 depending on what it is used for. You can get any of the brass fittings at a truck supply place and home depot also has a large supply of just about any fitting you will need.
You will to get the check valves at a truck supply place like a bus repair place or kenworth, volvo, etc. I had to go to a special company to get the air switches.

06-15-2009, 12:16 AM
air fittings are easy to install. lots of places to get them. there is an air and hydraulic fitting store i get mine at.

for the fittings that are quick release, when they work, you push the ring in and pull the hose out. that simple. the old plastic and metal ones are brittle and break, i have replaced alot of them too.

the black ball is a vacuum reservoir. there will be two hoses on it. one from the pump and one to the dash heater control. the only vacuum operated thing is the vents for defrost and vent controlled by the dash AC panel. unless it has been replaced, the vacuum pump is mounted behind the drivers side headlights somewhere and is air operated. mine failed and they dont make air operated pumps anymore so i replaced it recently with a 12v pump out of a ford pickup and i mounted it in where my 110v air compressor is to make it easy to get to.


06-15-2009, 12:30 AM
The Parker Store is where i get my fittings. the parker store i go to is one near my home but there are lots of them. www.grainger.com has fittings,

ryderfleetproducts has them and on and on.


is a link for the quick release fittings that i have. you just have to match the fitting.

i know push type fittings people are concerned about, i am not so much concerned. that is what they used on the newell to start and on trucks and they are very easy to use. the plastic part does get brittle after 20 years....


06-15-2009, 12:45 AM
My '82 has an Air Actuated Governor as well. Good luck converting to brass, I agree. This should be simple but be aware that most Plastic Tubing takes a Brass Insert to Support the Tubbing when using a Compression Fitting.
I have a 110 Volt Air Compressor in the Engine Bay. Looks to be a good place to have it and close to where the Engine Compressor comes into the System. By the way, it is a very good thing that this was here, the Prairie Schooner had sat for 5 years prior to us buying it and had numerous Fuel Problems. With an Air Actuated System it is very nice to have an Auxiliary Compressor. On mine you simply Plug it in and make Air Pressure.
The 6 Volt Batteries are most likely around 225 Amp Hours with 2 Banks or 450 Amp Hours. With a 40 Amp Charger I would guess you should have it on overnight. This type of Battery will take 90% of it's Charge Rapidly and then the other 10% Slowly. It sounds like it would be worth changing the House Batteries out (this gets rid of one problem simply).

Richard and Rhonda
06-15-2009, 01:34 AM
Hi Jennifer.

First of all, you should not have or use any plastic fittings. Someone before you made a big boo boo. Plastic tubing yes, plastic fittings no. Maybe I misinterpreted, and you meant the plastic ring on a push style fitting.

Compression fittings are not hard to install, but you have to have two wrenches, one to hold the fitting and one to turn the compression nut. Make sure you use the little brass insert that goes inside the plastic tubing.

Any truck supply place will have DOT fittings, or McMaster Carr will deliver them via UPS. They were cheaper at McMaster than what I paid locally, which is ironic since McMaster is a high priced outfit.

The round ball is a vacuum reservoir. Diesel engines do not generate a vacuum at the manifold like gas engines do. So to operate the HVAC controls, you need vacuum. You will find somewhere on the front firewall, usually driver side underneath, a 12V vacuum pump. Tom made a previous post about replacing his.

06-15-2009, 01:38 AM
You Guys Rock! The amount of knowledge in this forum is huge. I will pick up fittings tomorrow and see about getting that brake check valve replaced.

Richard, as far as the genset issue goes, I am waiting for the batteries to fully charge and then I will load test them. I bought a new fuel solenoid and will replace the old one after I determine what's up with the batteries. As soon as I totally fix the multiple generator symptom issues I will post my solution to the problem. The house batteries operate the fuel solenoid on the genset. I think the solenoid is not getting a consistent 12 volts. Cheers, Jennifer

Steve I have 6, 12 volt batteries. My gut tells me they are toast. The load test will be the final answer.

I am back on the air issue tomorrow! Thanks again you guys and I hope to meet you all in person someday! Jennifer

06-17-2009, 05:45 AM
I took the coach in to Western States Cat which is who Newell recommends work on our Coaches here in Missoula to replace the check valve on the brakes air tanks. They tested it and told me it was not malfunctioning. I also asked them to check for any air leaks under the coach where I wasn't going. They did find a small leak under the throttle or brake pedal which I told them about and couldn't figure out how to access through the floor. They will contact Tommy at Newell to figure out the easiest access to that area. Other than that, they said they could not find anything more leaks. I reminded them of all the systems that are air actuated and they said they would recheck and look again like the windshield wipers as well as the transmission. I am stumped as to why the supply air and the brake are decreasing together. Anymore thoughts on this? I may have them replace the check valve anyway. The air is still dropping 60 PSI in 35 to 40 minutes.

They also checked and load tested the house batteries and they tested good. I had been charging them for 1 week with the charger on board which puts out 40 amps. They said they weren't fully charged had to charge them to full before load testing them. Their charger puts out 30 amps. This sent up a red flag for me so I asked them to check the output of the alternator as well as the on board charger. I'll find out the results in the AM. These batteries are 5 years old. I wonder if I should just replace them as I just replaced the engine batteries.

Hopefully tomorrow they will have different and more productive results for me. I'm feeling a bit discouraged. More of your expertise would be greatly appreciated! Thanks guys, Jennifer

06-17-2009, 06:03 AM
If the batteries load test OK, I don't know that I would replace them. I would be more concerned about the battery charger not charging them up in a week. It shouldn't take long to charge up good batteries. I would share your concern about the alternator if you drove it very far since you should have a 100-150 amp alternator on the DD.

The only way the air system could be leaking down as you describe AND the check valves to be working properly would be for there to be a leak in the brake system after the check valve. If the two brake systems are leaking down together that would be a very unlikely potential and I still suspect the check valves are bad. There should be a check valve for each of the two brake tanks. A small leak will cause air pressure to drop rather quickly with no air being replenished. A leak at the air throttle or the air wipers would result in the leak down rate you describe.

Wally Arntzen
06-17-2009, 02:41 PM
Jennifer, have them soap down the tanks themselves. I had two tanks that had leaks in the welds of the seams on the ends of the tanks. If your losing the air that fast and the check valves are not bad its something bigger than they are looking at. I got my new tanks from newell. Another place to look is the air preasure control valve for the tag if you have one or any other air preasure control valve you may have.

06-17-2009, 02:52 PM
I just spoke with the service manager at Western Cat and last night they found a service valve leaking (apparently the one under the brake pedal) and an air regulator valve on the transmission. I asked them to go ahead and replace the brake tank check valves. As of this morning they had no reports on the output tests on the charging systems. I'll keep you posted. Thanks again and again! Jennifer

Wally Arntzen
06-17-2009, 03:54 PM
Jeniffer, I can understand you getting discouraged, I felt that way many times with my coach when working on the air system problems. Now that they have found some leaks you will be surprised how much better it will get as they correct them. The tranny switch was a big one on mine and it was one of the last places that we checked. That is a very costley one to replace so see of they can rebuild it. My guy got a rebuild kit which consisted of some "O" rings and other little things but it was not a big deal.
Once you get the air system good to go most other things are a lot eaiser to deal with. Your probably going to spend more on labor that parts which us not unusual.

Hang in there and cheer up, your going to learn to love your Newell.

Richard and Rhonda
06-17-2009, 05:02 PM

The leak in the service valve would explain why the brake pressure and the house pressure are leaking at the same rate. The check valves are to prevent the pressure in the brake system from moving back into the house supply system if the house supply pressure drops. It's a one way deal designed to keep pressure in the brake system as a priority. However, if you have a leak in the brake system, which you did, then the check valves are one way, and the house air will continue to flow into the brake system until all pressure is exhausted.

I second Wally's comments. Don't get discouraged. I worked on a LOT of stuff the first six months I had the coach. Now the stuff I work on is mainly tweaks and minor repairs.

You are dealing with the double whammy of learning the systems and trying to bring them up to speed at the same time. It will get better.

When you do get it up to great condition, the best way to keep it there is to USE it.

06-17-2009, 06:31 PM
I can understand your frustration.I am fairly well experienced and became frustrated early on. These guys here at the Forum are willing to help and are experienced with many of the problems that you are experiencing. They helped me "over the hump", keep on you will come to love your Coach and when you go somewhere you will hear "it's a Newell".
If they Load Checked the Batteries and all tested good then most likely your issue would be the Cable Connections and or the AC Shore Battery Charger. If your's is an Original Charger it is a good time to up-grade it. The Battery Chargers are so much better today even better than the Charging Function of the HEART or TRACE Power Inverters. Here is a link to Battery Charging;

06-18-2009, 12:26 AM
Thanks Steve for the link. I have passed on all your suggestions and it has proven very beneficial to these repairs. They are on top of it down there at Western Cat. I am now intrigued by the battery chargers of today. How are they better? If there are better chargers than trace and Heart what brand would that be? I would like to get one ordered right away as the charger that is in the coach is the original! I'll keep you all updated. Richard, I'll be reviewing the genset issue with and generator expert tomorrow and will let you know. Thanks again, I'll write soon (duh!) and, I already love my coach..big time!

06-18-2009, 03:31 AM
most of us have intverter chargers that are "smart".

xantrex, outback are a couple of great ones. i have the freedom 458 by xantrex that is a 2kw inverter. if i was to replace it, i would get a pure sine wave versus the modified sine wave that i have now.

of course you might have to do some rewiring to install if you dont have an inverter charger now.

the original battery charger or "boiler" that came in mine and i bet is the same one in yours is still installed in the bay but unplugged.


06-18-2009, 05:09 AM
To expand on Tom's comments, the new technology battery chargers are multi-stage (typically 3 stage) versus the single stage chargers that were installed 15-25 years ago. The multi-stage chargers start at a high voltage (bulk charge) to put a large current flow into the battery. As the voltage of the battery bank increases, the charger reduces the voltage thus reducing the current that will flow into the battery (absorption charge) to avoid boiling the fluids out the the batteries, then when the battery is fully charged, they go into float mode so that the batteries are maintained at the proper level. In this mode, they will keep the batteries fully charged without the danger of overcharging.

Xantrex makes a standalone charger called the TrueCharge that could replace your current charger IF you do not wish to install a combination inverter/charger. I replaced by Heart inverter with a 2kw ProSine inverter/charger. I wired it in replacing the existing inverter and just unplugged the existing battery boiler. At the suggestion of Newell, I left the existing battery boiler in place. Reason?? The only downside to the new multi-stage battery chargers, either standalone or as a part of an inverter/charger, is that if your batteries get accidentially drained down to a very low voltage, the multi-stage chargers will not see a high enough voltage to turn on while the old single stage chargers will take a battery from just a few volts and may be able to bring them back to life. I picked the ProSine because it is a pure sine wave versus a modified sine wave inverter. This is much easier on electronic equipment. It produces power with low harmonic distortion, runs inductive motors cooler and quieter, and reduces electrical noise that can interfere with the operation of laser printers and other devices.

Newell currently uses Outback pure sine wave inverter/chargers.

Wally Arntzen
06-18-2009, 12:37 PM
I have the Xantrex true charge in my coach. I put it in shortly after I got the coach about 5 years ago. It has been a great and as Michael says there are several other ones that are just as good or better.
Shortly after I put mine in I was in a storm in the mountains of Nortth Carolina and got struck by lightning which put out the charger and 2 brand new Cat maintainance free batteries I had just put in. That was a costley repair that I don't want to repeat.
Fortunately I was carring my old one with me and hooked it up to get me home and get another true charge and 2 new batteries.

06-18-2009, 03:09 PM
Morning Wally, Which Xantrex True Charger do you have? What is the amp output? Is amp output directly related to how many amp hours your battery...or batteries are rated for. In my case each battery is rated at 120 AH. I have 6 batteries. I'm not sure which charger would do the job. The True Charge I think has been replaced by the True Charge 2. Thanks again, Jennifer, the endless researcher and question asker.

06-18-2009, 03:22 PM
Jennifer.....after having 3 of my 8d batteries boiled by the original 70amp battery boiler in my 1982 Newell, Michael Day suggested I check out a multi stage charger made by Intelli-Power by Progressive Dynamics. The one I got was 80amp. It also has a de-sulfating mode. Here's a link to the one I got:


Since I installed this converter I have had NO batteries boil over, and they stay charged.

06-18-2009, 04:18 PM
The Progressive Dynamics that I recommended to Clarke is a higher output charger than the Xantrex TrueCharge units. You likely have a 75 amp charger currently. I have a 75 amp Magne-Tek as original equipment. Xantrex recommends a 40 amp charger if you have more than 200 amp-hours of batteries (this assumes 12 volt batteries, if you are using 6-6volt batteries of 120 amp-hrs each that would be 360 amp-hrs at 12 volts) or a 20 amp charger if you have between 100 and 200 amp-hrs. A larger charger recharges your batteries faster. My ProSine 2KW has a 105 amp 3-stage charger built in.

Wally Arntzen
06-19-2009, 05:58 AM
Jennifer, I am responding from a different location than my coach. I will check my manual on the Xantrex tomorrow afternoon and sent you the info. Michael knows much more about the capacities of these units than I do. I have 2 8d's for the coach and 2 8d's for the house and the unit that I have is excellent for my situation.