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SebastianD · 09-14-2003, 12:46 PM

Hey Brett,
my Excella 28" 79 airbags look like your old ones, so I'm thinking of replacing them. Have you had a chance to go for a drive, and do you notice a change in ride feel?
I'm also wondering where you got them, and what was the model number and price?
Thanks, Sebastian

thenewkid64 · 09-14-2003, 12:56 PM

Sebastian,

I took it on a short trip around the block. I can feel a difference, it seems firmer. The main difrence is from inside. Before if I jumped up and down in the rear of the coach I would get a one to two inch bounce. Now it is like a half inch.

The bags may be spefic to your rear suspension. but I used the Firestone W01-358-5405. This is a heavy truck part number.

I purchased them from Fleetpride. www.fleetpride.com

The bags were quoted at 130+, that was while they were out of stock. After this latest production run they came in at 141.00 each.

SebastianD · 09-14-2003, 01:23 PM

Thanks Brett,
one more question if you remember... when I look at my airbags pumped to 80 psi (truck stop told me not to go over 80 untill I replaced them), there is about five inches of the metal showing on the bottom. It seems that in order to get the right ride height, that is about where they need to be as well, but the metal beam that they attach to si pointing down a bit. I'm just wondering if I also need to loosen it from the axle, and lign it up again? Is there any way that you could take a photo with them installed?

Thanks again, Sebastian

thenewkid64 · 09-14-2003, 02:41 PM

Sebastian,

I can take a picture for you, but I don't think you want to try what you describe. I looked at the exploded parts diagram and I do not think that you can do as you describe to adjust the lift height. When I have mine inflated to the factory cut off point I have 1 1/2 to 2 inches of the bell showing. The bell is what the bag rests on. If you have 5 inches of bell showing, how high off the ground is the rear bumper?

Here is the info from Inland RV on this issue:

Classic Airstream Motorhome and the Argosy Motorhome height's are not measured from the bumper. They are measured at the air bag itself.
From Serial number 9622 and back (81 and back), the ride height from the top of the air bag plate to the bottom of the dish, is 8 3/4 inches.
From serial number 9623 and up (1982 & up), the dimension is 10 1/2 inches.

I would suspect that a PO set the MH up to the post 82 settings base don the 5 inches of bell showing. That or the air bags you have are not the correct ones. Just me guessing though.

PeterH-350LE · 09-14-2003, 03:57 PM

at ~95psi my bags are 10 1/2 " with 2 1/2 " metal showing.
I could not ride @ 8 3/4"
Sebastian, the slight slant seems to be normal.

ALANSD · 09-14-2003, 04:16 PM

Peter- I noticed your air bags are rigt next to the wheel, mine are more center- located on the rear axle.. Also no matter how much I pump I don't get more than about 6 inches of height from the top to the bottom of the dish.

thenewkid64 · 09-16-2003, 04:17 PM

Peter,

I finally got to measure today. I wanted to get the new compressor installed so I could give a true reading.

I also have 10 1/2 inches from top to bottom plate. I have 2 1/2 or so of the bell showing too. Sounds like the suspension is the same.

Alan.

If you are filling from the gas station or at home you need to have the leveling valves/selinoids (sp) powered up. They allow air in and out based on the linkage that connects to the lower rail. I know you have a power problem regarding the compressor. If you have no power to the valves or compressor you will get no additional air in the bags. This is based on the drawings I have. Using my wiring as a guide. I have a yellow wire that is attached to the power feed that comes from the ignition switch. If the valves have no power I do not think they will dump or fill the bags. The relay in the grey box that is mounted to the compressor just turns on and off the compressor, the draw from a bad compressor could be what is blowing fuses. If you remove the small nut that holds the cover on you will see the screws. You could disconnect the compressor(remove the wire from under the right had screw on the left hand set) and at the least the valves would work as designed. This would require you to have the key on for the bags to fill/dump.

PeterH-350LE · 09-16-2003, 05:50 PM

Thank you Brett for measuring yours.
We can now reasonably assume that the earlier coaches were supposed to run @ 10 1/2 " and the later ones with the bags in a different location (on top of a cross beam) at 8 3/4.
The later models do not have the two solenoid valves, nor do they have two leveling valves just one in the center.
The earlier set-up allows side to side leveling and also isolates the airbags via the two solenoid valves with the ignition off.
Makes me wonder why they did the change, since the side to side leveling seems to be a valuable option.
Reading some posts about deflating air bags when using levelers, also makes me think that not using the solenoid valves in the later coaches was not a smart move.

thenewkid64 · 09-16-2003, 05:57 PM

I would be willing to bet the reduction of parts and smaller airbags created a reduction in cost. I like the way mine works. If the Roadside is heavy (full tanks) the roadside bag will have more air in it. I run level. I like it.

SebastianD · 09-16-2003, 06:20 PM

Thanks Peter and Brett, you guys rock! Where else would you find a total stranger willing to clinb under a several ton vehicle with a digital camera?

Sebastian

thenewkid64 · 09-16-2003, 06:24 PM

No problem for me! I seem to be under it on a regular basis. At most rallies that I have seen pictures of Peter is not only under his, but everone elses too.

It is an illness that you have yet to feel the full effects of. My wife knows when I get up from the computer, camera in hand, that there is someting on the forum that needs a picture to help explain. She just shakes her head and is glad I don't have any other addictions

PeterH-350LE · 09-16-2003, 07:47 PM

Quote:

Originally posted by SebastianD
Thanks Peter and Brett, you guys rock! Where else would you find a total stranger willing to clinb under a several ton vehicle with a digital camera?

Sebastian

We only climb out from under it to check on the forum.

ALANSD · 09-17-2003, 05:15 AM

I have been under mine so often I feel "married" to it

Thanks Brett fo rthat tip- it might explain why the bags don
t seem to inflate any more. I checked for leaks, didn't find any. So I will try what you said, I have a power connection ready to attach, fused and all, I had it attached to the isolator output where to old line was burnt out. Heavy duty wire and fuse. I migh try to hook it back with the compressor power line off and see what happens when I pump em.
If i eliminate the compressor and go to manual feed, it will have to bypass all that leveling stuff. I intended to pull the compressor and try to repair it or replace it, but have not yet gotten to that.

thenewkid64 · 09-17-2003, 05:23 AM

Alan,

The compressor replacement is a straight forward job. Mine was 3 bolts and dissassembly of the fittings to get it out. I had to drill 2 new holes as the new feet did not line up with the old holes.

I was able to with some watching get a new Thomas 315CDC45/12 Compressor for $102.00 plus freight on Ebay.

It arrived last night and I installed it in less than 2 hours.

From the duty ratings it looks to be the current equal to what I pulled out.

Good luck on the wiring, etc.

stuart1 · 09-26-2003, 12:51 PM

Thanks everyone!
After reading all of the above I was able to figure out I've been dealing with a dead compressor so it's good to hear the job ahead is going to be an easy one.
One question for anyone who knows the answer: When replacing the air compressor what should I look for (PSI Volume of air etc)?
Thanks and happy trails...Stuart

thenewkid64 · 09-26-2003, 01:07 PM

You should be looking for a Max pressure of better that 100 PSI and duty cycle of 50%. I was able to get a 315CDC45/12 off ebay for less than 120.00 including freight. Works great and was a straigtforward install.

PeterH-350LE · 09-26-2003, 01:21 PM

Quote:

Originally posted by thenewkid64
You should be looking for a Max pressure of better that 100 PSI and duty cycle of 50%. I was able to get a 315CDC45/12 off ebay for less than 120.00 including freight. Works great and was a straigtforward install.

The 315/45 (also known as ARC5000) is great little compressor for the air bag system. It has minimum internal leakage and runs rather quiet when mounted on rubber boots.
Brett got his for a great price, they normally retail for about 180.-.
Since I didin't want to run additional air lines for an in-dash pressure monitoring gauge, I installed a warning light in the dash, which is lit when the compressor is running.
A continues light while going down the road would alert me of possible bag or line failure.

thenewkid64 · 09-26-2003, 01:23 PM

Peter,

I was just thinking about the light. Did you use the second set of contacts that are unused in the pressure switch?

I figure I could steal a bit of power from the compressor feed and have the output go to a dash light.

PeterH-350LE · 09-26-2003, 01:30 PM

Quote:

Originally posted by thenewkid64
Peter,

I was just thinking about the light. Did you use the second set of contacts that are unused in the pressure switch?

I figure I could steal a bit of power from the compressor feed and have the output go to a dash light.

I just wired it to the +compressor lead at the pressure switch.
Don't tell anyone I said this, but if you are using a 20 amp fuse for the compressor as suggested, go to a 25 amp. Both of the solenoid valves run of the same power source and you will find that the 20 amp will blow sometimes.

thenewkid64 · 09-26-2003, 01:38 PM

I concur on the fuse issue. My Manual says 20 amp, but a 20 amp would not even start the old pump. So I went to a 25 amp. It would get warm when the pump was in overload, but it did not blow. I left it in for the new pump.
I may swap it out to the new blade style with a weatherproof cover as the plastic is getting brittle from the heat and age.