No air in rear air bags - 1997 Prevost XL 45-E

DoubleEagle · July 19, 2016, 11:30:25 AM

Quote from: Jon on July 19, 2016, 08:09:13 AM

If the air system has not been maintained and the norgrens within the system are filled with moisture and aluminum oxide which becomes a paste almost you have a whole coach issue of fairly large proportions. But if the system is dry and has been maintained you may just have a problem with on valve.

As I said before, it is important to check the air dryer to see what state it is in, if it is all gunked up with gray paste, lack of dryer maintenance may have caused the whole miserable situation.

Jon · July 19, 2016, 11:51:28 AM

While I agree fully that a poorly maintained Prevost air system is a recipe for disaster, step one still should be to identify the cause of the current problem. If in fact it is that gray sludge affecting the operation of the suspension system valves, then it is likely the problems are widespread affecting all norgen valves, air bags likely have some water in them, protection valves probably may not work due to corrosion, and the brake chambers are likely rusting inside, prematurely wearing out or damaging the diaphragms.

Or it could just be as simple as a single bad valve.

eagle19952 · July 19, 2016, 12:21:35 PM

So...back to square one....get air in the tank by any means possible...and run with your wallet to some place that knows what the heck they are doing...

Jon · July 19, 2016, 12:35:55 PM

If the Prevost is at a shop, air can be introduced to the accessory system only via the Schrader valve in the front steer compartment. If the brakes have air pressure and the accessory tank does not, and air has to be added the problem is a bad protection valve at the secondary tank. But if the accessory tank has air pressure the problem is elsewhere.

This shouldn't be difficult.

brmax · July 19, 2016, 12:38:05 PM

Its a bummer in any travels, but with the help from the site here I sure do see it a great resource.
I'm sure many of these newer coaches have these valve types below and we may look at them to gear up or deny them

Just kiddin, these here are neat but also can be a pita as mentioned when a frame is stacked with them. They been putting various sorts of these on trucks for quite awhile, and especially in safety options as doors "leveling" for un-loading of dumps, and you can imagine the designed stuff from people at the pencil desk

https://imagehost.isoftdata.com/phpThumb.php?src=partimages/254076/&productcode=254076&id=395249&w=500

Multiplexing Architecture
Unlike the electrical systems on previous models, which utilized point-to-point wiring for all input signals and output loads, this system uses multiplex technology to provide control and communication between major functional areas of the vehicle.
Multiplexing simply means: communicating multiple pieces of information via a single twisted pair of wires (called the data link) without requiring a wire for each piece of information. This information could be gauge information such as engine oil pressure, or switch information that controls vehicle functions such as headlamps.

mechanics always thinking outside the real box dangit
Floyd

luvrbus · July 19, 2016, 12:53:39 PM

LOL I counted 5 of those boxes on Gary's 2010 Prevost RV chassis and 8 on the 2014 H model seated coach the casino owns

brmax · July 19, 2016, 12:59:45 PM

Yes Sir, exactly as I was just thinking I should have put in the post we made labels and turned them on with the laptop in whatever way was desired, on-of, signals, percentage whatever.
I thought it was bad with just the 2 of these on a dump frame, finding as you said they kept upping the game.

Floyd

OneLapper · July 20, 2016, 07:45:32 PM

Here's the update........

I pulled it from the shop it was at because they did not order the trans cooler when I told them it needed to be ordered. They charged $708 to diagnose the leaking trans cooler and inop air bags, despite the fact I told them was was leaking and gave them the part number for trans cooler. Total waste of money let alone precious time.

After the driver got the bus out of there, I drove to the bus in Boston last night and tried to figure out the air bag problem. I gave myself 30 minutes to diag the problem before I started on a work around. I crawled around under the bus, in the dark, deflated air bags and all, found the norgren valves for the rear axles. No air to either valve, and no air after them. I quit there and started on the Yankee Ingenuity repair. I ran a 1/4" nylon air line from the 115v air compressors regulated output to the rear. I removed the drain valves on the air bag tanks and installed nylon push lock fittings and a tee between the tanks and connected the air lines. I set the compressor's regulator to 60 psi and in 5 minutes it was up on air again. Done till it gets off this tour.

The tranny cooler leak was very small, dripping coolant once every 5 seconds. I had the driver remove the expansion tank cap the night before and the leak was minimal. I decided the leak was minor enough and sent it to the venue to pick up the band with 15 minutes to spare last night. Earlier in the evening I had ordered the norgrens and tranny cooler from Prevost in NJ. After the show last night, the driver got to Prevost in NJ at 7am to get the parts, then continued on to Philly to drop the band, then head to US Coach in Vineland. Well, 74 miles from Lukes the cooler blew on the NJ turnpike. All done. Rented two vans and got the band to Philly, then got raped by the tow company for the hook and drag to US Coach.

Luke got the bus at 2pm and Bill worked as hard as anyone could to get the cooler out and the new one in time for the bus to make it to Philly to drive the band to Detroit tonight. Thankfully the band had already decided to fly to Detroit tomorrow morning and hang out there during their "travel day" instead of riding in a bus, so that gave us an extra day at US Coach for them to finish the job.

I have to say I'm seriously impressed with Prevost's parts dept. 7am to 7pm CST, parts pickups till 11pm! Give them the last 8 of the VIN and they know EVERYTHING about your bus. Create an account and order away. Plus free ground shipping. And ordering the part direct was 50% less than the truck shop wanted... yes, a 50% markup above Prevost's over the counter price.

I also can't say enough about Luke and Bill at US Coach. They are great people, know what they are doing, and support us in a way that most of us will only realize when these two people retire. There is no one north of Vineland NJ doing what they do. Thank you Luke and Bill!

robertglines1 · July 21, 2016, 08:46:12 AM

bunch of hoses on those norgrens. Been there. Mark good. would suggest good time to get rid of the push fittings. Glad your running again. I had a picture of that bank of them on rear compartment wall but it wouldn't post. To darn complicated--both the system and pic posting. Check and see if you have power to center solenoid on back wall of steering compartment drivers side. 5 Stack Key on.

luvrbus · July 21, 2016, 09:05:26 AM

I knew you could figure that out Mark BTDT try as hard as Prevost does people with common sense can get around all their complicated crap.

10-4 on Luke he came through with some studs for me MCI wanted $38.00 each he sold me some for $15.00 each such a good deal I bought 20 of the studs and now have plenty of extras I will never use

Jon · July 21, 2016, 10:55:41 AM

Maybe at one time Clifford, but with the multiplex coaches without programming you cannot even change the type of light bulbs.

I wish the bus companies would go back to solid front axles, relays and circuit breakers. And skin that is held in place with rivets.

Jon · July 21, 2016, 10:55:52 AM

Maybe at one time Clifford, but with the multiplex coaches without programming you cannot even change the type of light bulbs.

I wish the bus companies would go back to solid front axles, relays and circuit breakers. And skin that is held in place with rivets.

luvrbus · July 21, 2016, 11:08:53 AM

Quote from: Jon on July 21, 2016, 10:55:52 AM
Maybe at one time Clifford, but with the multiplex coaches without programming you cannot even change the type of light bulbs.

I wish the bus companies would go back to solid front axles, relays and circuit breakers. And skin that is held in place with rivets.

Yea the chassis electrical is a different world Jon, first time I got into that was a changing a speedometer head Jon my H-41

OneLapper · July 21, 2016, 06:28:58 PM

Driver picked up the bus from Lukes at the end of the day and 20 miles later it started to over heat. It seems to be air locked. He's added 10 gallons or water so far but it still over heats after a few minutes.

Trying not to lose hope on this bus.....

billy6941 · July 21, 2016, 06:38:36 PM

I drive a 2016 Prevost H-345 passenger coach and the parking brake won't release until u raise it to ride height.