[77newell]

The compressed air system on your coach consists of two major sub-systems; the braking system and the suspension and other uses system. These systems are supplied by one common supply pipe that can be hooked to various sources of pressure with the engine pump always there. The two sub-systems are separated by a PPV (pressure protection valve) so that preference is given to maintaining air pressure to the braking system. Unless the pressure in the brake system is above 65psi no air is supplied to the suspension system. Since you have trouble getting above 50psi I think you have a leak in the braking system. A quick check of the automatic drains on the three air tanks would be a good starting place. I've also had the pressure relief valve on the rear tank (the only tank with one as far as I know) leak like crazy.

It is possible that the PPV has failed open and that then leaks in the sub-system feeding the suspension could be limiting pressure buildup. One indication of this would be if the supply gauge and the brake gauge pressures rise together. On my coach the brake gauge will rise slowly to about 65psi and then the supply gauge will rise very quickly as the PPV opens. Another way to check this is to close the two valves on the bulkhead just ahead of the rear axle that supply air to the front and rear suspension. If the air pressure now comes up within a few minutes then the PPV is bad and you have leaks in the suspension sub-system. (What I've titled "suspension sub-system" includes more than just the suspension, it includes air doors, gen slide, stair slide, air horn or any other use than for the brakes)

Let us know what you find and we'll help from there.

[nuevomex]

David
This group is the most knowledgeable, helpful and friendly bunch you will ever find and they take great pleasure in providing the information and guidance you need. It's great for Newell to see a coach like this brought back to near original condition. Good luck and as they all say, so wisely, one step at a time, first things first and all of that, and more.

[PermianRaptor]

David, you have just disproved conventional Newell wisdom.    I have been told all along that 214 was the first Series 2000 but based on the photos, your coach is definitely a 2000 Series and based on the VIN number it is definitely a 1990 model.  Congratulations, I have lots of changes to make in my database and history!!

Well, isn't that a way to introduce myself, only by breaking the once-correct numberings of the coaches! I was fooled myself, wondering if it was an 89 but it seems like at the turn of the century, they did get many changes.

[PermianRaptor]

The compressed air system on your coach consists of two major sub-systems; the braking system and the suspension and other uses system. These systems are supplied by one common supply pipe that can be hooked to various sources of pressure with the engine pump always there. The two sub-systems are separated by a PPV (pressure protection valve) so that preference is given to maintaining air pressure to the braking system. Unless the pressure in the brake system is above 65psi no air is supplied to the suspension system. Since you have trouble getting above 50psi I think you have a leak in the braking system. A quick check of the automatic drains on the three air tanks would be a good starting place. I've also had the pressure relief valve on the rear tank (the only tank with one as far as I know) leak like crazy.

It is possible that the PPV has failed open and that then leaks in the sub-system feeding the suspension could be limiting pressure buildup. One indication of this would be if the supply gauge and the brake gauge pressures rise together. On my coach the brake gauge will rise slowly to about 65psi and then the supply gauge will rise very quickly as the PPV opens. Another way to check this is to close the two valves on the bulkhead just ahead of the rear axle that supply air to the front and rear suspension. If the air pressure now comes up within a few minutes then the PPV is bad and you have leaks in the suspension sub-system. (What I've titled "suspension sub-system" includes more than just the suspension, it includes air doors, gen slide, stair slide, air horn or any other use than for the brakes)

Let us know what you find and we'll help from there.

The brake system got up to about 50-60, once it did then the "Supply" gauge also shop up. It sounds like the PPV is good, but the generator door did have difficulty getting out. The cooler on the side came out like nothing. This did take a solid 10-15 minutes of 2,000+ RPM rev. I have read here that there is a way to connect a compressor to the air lines, which I have a compressor readily available. I will also look for this tank, as I'm sure that the leak is in the braking system and that's why it can't get up to the pressure it needs, and another reason why the air bags won't get up. Thank you so much for the detailed response.

[ccjohnson]

I have had problems with air leaking through my air shift modulator on the transmission twice. Once I had it rebuilt at Newell. Second time Stewart & Stevenson installed a new one.

[77newell]

There are three tanks. The first tank after the compressor is the so-called supply tank mounted just ahead of the drive axle. From there air is sent forward to the two brake tanks mounted aft of the front axle. Each of these tanks has a check valve in the supply lines going to them. Perhaps one way to tell where to look for leaks is track the pressure decreases in each tank once you shut off the engine. There are two needles on the brake gauge, one for each of the front tanks.

[encantotom]

you will have to make a short adapter hose or change the end on one of your air hoses. i got a short 2 foot hose and put a male air disconnect fitting on both ends. that way you can plug into your compressor hose and then the female disconncect that is in the engine bay on the passenger side. it will be obvious as they are there to use for airing your tires up or other things needing air.

it is easiest that way you dont have the engine running. the farther away your compressor the easier it is to hear the air leaks.

alot of us have bought electronic leak detectors as air leaks are a challenge for all of us. (doug....someday for you too....ha)

tom

[77newell]

I did something similar to Tom, I put male air chuck fittings on both sides of a ball valve. That way you will have less air blasting when you disconnect.

[encantotom]

actually, i also made one of those. i had forgot till you said that......ha

tom

[Yort]

Running the motor at 2000+ RPM for 10-15 minutes with no load on the motor may not be the best idea, I believe that's near max rpm. An auxiliary compressor for pushing air into the system would be a much better solution.