Hello All,
So one of my Reno list items for my new '86 Grand Villa 3300 GVF SBI is to figure out how to work the Air Suspension for the tag axle.
Right now the air pressure gauges on the dash reads 0 PSI. The manual says I shouldn't drive it with less than 3PSI.
The only problem is the two switches on the dash don't appear to do anything and I can't find anything in the manual about it's operation.
Under the left side of the coach, one of the storage bays has an air pressure hose. I assume that goes to whatever air pressure tank is used to fill the Air Bags for the Tag Axle.
But I've found no switches for the Air Hose either.
Nothing that would indicate how to turn on the Air Pressure system to either fill or lower the Tag Axles or use the air hose.
Any ideas? Does the engine need to be on? Does the generator need to be on? Where should I look for the on switch for the air system? Do the left and right "Raise/Lower" Switches for the tag axles control everything? If so, how do I work them?
Sorry for all the newby questions. Thanks!
Also, let me know if pictures of anything would be helpful.
Photos are ALWAYS helpful when you ask questions. Worth a thousand words, as they say.
You have a less common chassis, and there will not be as many members available with first-hand knowledge of your particular systems. BUT, we have some really smart people on this Forum, and once they SEE what you are working on, they will probably be able to figure it out!
Follow the air hose and see if it leads to the compressor and lines to the tag bags. I will bet that someplace on the dash there are switches that allow the bags to be filled. If you find little solenoids in the hoses, clean up the wires and maybe remove any tie tape wrap and see if any of the color is still there. If you get lucky the wires will appear under the dash .
Next step is to make a 40ft test lead and test light .. I stick my( 2bulb ) test light under a wiper blade and start checking for continuity at the dash . Batterys off.
Okay I added pictures to the original post. couldn't figure out how to add them to a reply.
First pic is Driver side air bag. looks okay.
Second pic is passenger side air bag. Looks badly busted.
Third pic is the dash controls.
Fourth and fifth pics are the instructions from the manual
sixth pic is of what I assume is the air pressure tank. Though I'm not sure on that.
Either use "Preview Post" at the bottom when creating a new post, which puts you into the full editor, or (globally) change your profile to not use the quick editor (I think it's in "Look and Layout".
Okay so in this post:
air bag replacement parts info (http://www.foreforums.com/index.php?topic=30144.msg259324#msg259324)
I found a discussion on replacing the airbags. They mentioned these were a good fit for replacing the airbags in the coaches that have air suspension all around. Would they word for my tag axle? I have leaf springs everywhere else.
AS9448 by CONTITECH - CONTITECH AIR SPRING 64286/1R11-150/8563 (http://www.finditparts.com/products/7889630/contitech-as9448)
It would REALLY be helpful if you had a air system schematic. I don't suppose you saw one in any of the paperwork or manuals that came with the coach? Two of the most useful tools you can have when working on these old coaches are the air system and the 12 volt electrical system schematics. Without them, trouble shooting is really difficult. Not impossible...but difficult.
As suggested above by Mike, you will need to figure out how the air is routed around your coach. Basically, there is a air pump somewhere on the coach. It may be electrical (12 volt), or it may be mechanically driven off the engine. Pressure from the pump will go to one or more pressure tanks. It may pass through a "air drier" on the way to the tank...or not. From the tank (or tanks) it will be piped to anything that uses air pressure to operate.
Without knowing
anything about your system, I would guess air goes from the pump, to a tank, and then up to the control panel on your dash. When you operate the two valves on the control panel you will pump up or deflate the air bags. The two needles on the gauge will show the air pressure in the bags.
Obviously, you will have to replace the damaged bag. You might be able to find a part number on the "good" bag. Until you do that, the whole tag axle suspension will be useless. After you get the bag replaced, then you can proceed with figuring out how the system works.
In the meantime, you might call FOT and see if they can provide you with a air system and electrical schematic.
I foreget if you have air brakes or not. If so the compressor will be the front belt and hung under the crankshaft of the engine. IMHO. This will fill an air tank or two/ These wil have cables leading to the edge of the coach and able to to be tugged daily to remove air/water.
If you have juice brakes the air compressor will be 12 volts and mounted closer to the air tank or direct drive the air bags. This system does not require a tank and may not have one . The dash controls look like air valves and not electrical switches. Tip the dash up and have a peek.
Unlikely that you will find the part number sticker on the bag. When you look at the rubber bellow you will see the manufacturers name and then in a small oval you will see a number stamped. That is the bellows number. Then you need to look at the top and bottom plate for diameter and layout of bolts/fittings. When you look up the bag in the book you use the bellows number and there will be several with that bellows and different top and bottom plates. You match up what you have based on that. I recommend that you take the whole bag with you if you haven't done it before and let the parts person do it. Also use a truck shop that deals in airbags a lot. Some parts guys won't even ask what it's out of. You can tell them the truth or tell them it's off a lift axle on some home made farm trailer.
I don't know how your system is set up. I would look for your compressor and see if there are any tanks. You could pull the panel with the adjusters and see if the air lines from the delivery side to the airbags will hold air. As well you can see if there is any air supply to it. There are 12 volt air compressors you could install and run line to the supply side.
Your 6th photo certainly looks like a air pressure tank. The little valve on the bottom is probably a water (condensate) drain.
I'm guessing the air hose you found in the storage bay does lead to the air tank. If it has a female quick connect fitting, it was probably used as a "tire filler" hose. Most of the later coaches have a hose like this. If it does go to the air tank, you can also use it to put air into the tank. You just need a double male quick connect adapter, and a portable compressor. If you can get a little air pressure built up in the tank, then you can play around with the tag axle control panel, and see what is working and what's not.
I wouldn't buy another air bag until you try to put some air in it. It might be that way from driving the coach without any air in it. It might just pump up fine. There must be a compressor somewhere on the coach - and it's apparently not working. It might be a 12 volt unit (first guess) or engine mounted.
Those are Williams Air Control valves. They are push/pull. They were used for many years on the
Bostrom air ride seats in large trucks. Go to the back of the valves and open the 'in' fittings to see
if you have air pressure to your valves, if you do retighten those supply lines. Next loosen the lines
that go out to the air bags. Press each valve down and see if the air flows through. If both have air
flowing through, tighten the fittings. Then follow the air through to the bags. If the lines look good,
then go to the bags. Loosen the air lines to them and have some one push in on the air valve and if
you have air to the bags you should be good to go. It takes a good amount of air to fill the bags and
will not happen by just hitting the valve, it will take a little while to fill them both, be patient and watch
the gauge.
Good luck on your project .
Carter-
From the pictures, one air bag is totally ruptured. has to locate the air compressor if it is still there and powered and operating, first and foremost.
I can't tell by the pic if that bag is ruptured. It might just be folded up in itself. It's happened to my big truck when working on it at times. Add air and it pops back in place.
There is a12 volt compresser I think that it's mounted under the coach either near the tag axle or might be in the area of the step well
Okay, So I crawled under to have a look around and lifted the dash.
Picture 1 is something mounted next to the pressure tank. I assume that's the compressor.
Picture 2 is another view of what I think is the compressor. You can see the pressure tank in the top half of the picture.
Picture 3 is the back side of the pressure tank.
Picture 4 is another unknown gizmo that looks like it might be connected to the pressure system somehow.
The dash definitely has air hoses hooked up to the to the valves. I'm not getting pressure to them. But I can't figure out how to turn the compressor on. There are no switches for it anywhere in the coach that I can find. It doesn't seem to turn on when I turn the engine on.
Any ideas how I can turn the compressor on?
Does the thing that you think is a compressor have any electric wires attached to it? Anything that looks like a power supply wire?
If you can find a place on it that looks like the power connection, you could try powering it with a long jumper wire off the battery.
That doesn't look like any air compressor I've ever seen, but that doesn't mean anything.
The other doohickie is some kind of valve or regulator. Need a better photo of the top of it (where hoses connect) to make a guess.
I started a little Google search. I think I may on the trail of something at least similar to what you have. The thing next to the air tank may actually be a booster for the tag axel brakes. Does your tag axle have brakes? Try looking through the thread linked below, and check out the photos. See if any of it looks close to what you have.
Hydraulic Tag Axle Brake Information - iRV2 Forums (http://www.irv2.com/forums/f65/hydraulic-tag-axle-brake-information-101083.html#post938300)
In your first post, you had photos of excerpts from a instruction sheet of some kind. Do you have any kind of manual for the tag axle? I think I found parts of a manual with the same info pages as shown in your initial post. Page 22 shows a diagram of a belt driven air compressor. You may have one of these compressors "hidden" in your coach somewhere. Look in all the storage bays and under the coach.
http://truckroadservice.com/barth_attachments/7421043732_Neway_Suspension_Maintenance_Files.pdf
Pic 1& 2 looks like a vacuum booster for the brake system.
Pic 3 I am clueless on, kind of looks like the reserve air tank?
Pic 4 Looks like an inline fuel pressure regulator.
Carter-
I think it might actually be a Syncronyzer relay valve (transducer). See the photo on the page I linked in reply #18.
Carter,
I think you are getting close to what is there. I believe this is what used to be called a Hydrovac brake system and all the parts are part of the brake system. in picture 4 you can see hydraulic brake lines at the frame.
Disclaimer, I could be wrong
X 2 the declaimer.
Carter-
I would try to identify the hose that is the supply and trace it back to the compressor. It could be anywhere, include just behind the front bumper. I'm going to guess it's an electric powered compressor and not engine mounted. Foretravel seems to like the high end Thomas brand so it might look like this: Thomas 12 volt Compressor (https://www.zoro.com/thomas-piston-air-compressor-110hp-12vdcv-405adc3812/i/G0626832/?gclid=CKL0vJbU_tMCFQ9EfgodoVsFdw&gclsrc=aw.ds)
I will give my guess on how it might be controlled: Main power comes to it through the ignition (no sense running the compressor when parked). There is an automatic pressure switch that turns it on when pressure is below a set point (say 75 psi) and turns it off at a higher set point (say 100 psi).
I doubt there is a dash ON/OFF switch but look for a fuse for it. Maybe you already know this, but if you coach is like other Foretravels the dash will lift up and expose the wiring along with fuses. A fuse identification diagram will be attached to bottom side of the dash cover. There will not be a lever or handle to lift up the dash - just start pulling up (gently) on the overhanging edge; it hinges on the long side closest to the windshield.
I've got a 1986 GV 33' on a p30 chassis with 454 cu in gmc/chevy engine with tag axle. The brakes and power steering are hydro -vac. The front suspension is air/spring (an air bag inside a coil spring manually inflated). The tag suspension is real air bag suspension inflated by an electric compressor located back near the tag and actuated by the ignition switch. It shuts off automatically by a pressure switch and each side is manually pressurized by manual valves on the dash with a dual gauge. Your mileage may vary.
wantabe
Agree with John. Ft used a high dollar compressor and hid them, like Easter Eggs
all over the place. I doubt that there is an engine driven compressor as they eat up
the output of an engine and any gas engine in a FT needs all the horses it can muster.
Good luck in your redo,
Carter-
That is the brake booster for the tag axle. The compressor should be 12 volt and as had been mentioned may be in the area of the front bumper area it should have 12 volts when the ignition is turned on and I am thinking by pulling out on the knob for the controls for the tag axle may turn on the compressor.
UPDATE:
I managed to hook up an external air compressor to the hose in the storage cabinet. That fills the lines perfectly.
I get compression at both of the valves in the dash.
I can fill the left bag just fine. It holds air.
The right bag did pop back into place when air pressure was applied. But it doesn't hold air. When you put air to it, it just blows out. You can hear it when you try to fill the bag. So, it's either ruptured or it didn't pop fully back into place.
I haven't got the coach in a place where I can get fully under it to look around yet. (I don't trust the hydraulic lifts to get under it). I'll be taking it to my dad's this week. We should be able to safely lift it and get under it to see if the bag just isn't sitting right or it it needs to be replaced.
And hopefully we can find the damn air-compressor. Lol.
The bag is bad they are sealed units, not open ended.
That's too bad. Guess that means I need to figure out which bag it is and buy a new one.
If it were me, I'd buy two and replace both at the same time. If it is at all possible. If one went out, it's likely the other is close behind it.
Wantabe
Most of us replace all the air bags when we experience the first failure. The only exception would be if an external hit damaged a bag.
That's the plan. Still gotta figure out which one it is.
Michelle has a huge amount of part numbers
and she may well have that one, too. She is a
great asset to all of us on here.
Carter-
UPDATE:
FOUND THE COMPRESSOR! It was in the metal box. Took the metal box off. Found the compressor in there.
Tested it out with a battery. It turns right on. Tested the cables with voltmeter. It's getting power. Looks like the Solenoid is bad on the thing.
Found the parts list for the Ridewell system here: http://www.ridewellcorp.com/content/uploads/files/Ridewell_Full_Parts_Pricing_List___Effective_07.01.2017.pdf
And the solenoid part number on that sheet: 1237652B000 - SOL VLV 3-WAY 12DC MAC
Gonna see if we can order that from Foretravel, or Ridewell, or maybe the local CAT dealer who's listed as a Ridewell dealer.
Also, It looks like ridewell makes the Airbags too.
Might want to check into the air intake filters also, but depending on threads these might be sourced locally. They look pretty nasty, but may still be good.
You can also match up the solenoid at NAPA. You want a plow controller solenoid. HD and rated for almost 100% duty cycle . It is probably not a Ford Starter solenoid( short duty)
Looks like our boost solenoid would do the trick.
UPDATE:
We've now tested everything on the air compressor.
Good news... it all works. Solenoid is good. pressure switch is good. Wires are good. The problem is that the little wire thats running from the front of the coach isn't supplying power with the ignition switch. The big red wires are supplying power. But nothing from the little red one that closes the solenoid and gets the big power going.
This relates to another problem I'm having with the headlights. The headlight switch isnt getting power from the ignition switch either. So i can't turn on headlights. Powering headlights manually, they all turn on. Tested the switch, its good. Just not getting power.
So i need a wiring diagram to figure out where power is supposed to be coming from, but isnt. Probably a bad relay somewhere.
I'll start a new topic for that, since this tag axle topic is all basically solved. Found a place locally that both carries the bags and will install them. :)
Did you test the little red wire for continuity? Perhaps there's a brake in the wire.
UPDATE:
Finally got the airbags replaced with new ones. Ordered from TruckSprings.com. W01-358-5311 - Firestone Reversible Sleeve Air Spring. $138/per for anyone who needs them.
I also opened up the Pressure Switch... and parts fell out of it. It's super broken inside. All the wires are good though. So I just need to replace that. Also... inside there was a piece of paper with the wiring diagram and the part number for the switch. Square D 9013FHG Air Compressor Pressure Switch. I can order it from Grangers for about $50. So that will be all good.
While I'm waiting for the Pressure Switch to arrive, I ran a temporary ground switch into one of my side compartments so I can complete the circuit and fill the airbags when necessary.
I've got a pretty good understanding of the system now if anyone else has a similar system and runs into issues.
Zoro has it much cheaper
Square D Pressure Switch, DPST, 95/125psi, 1/4" FNPS 9013FHG12J52 | Zoro.com (https://www.zoro.com/square-d-pressure-switch-dpst-95125psi-14-fnps-9013fhg12j52/i/G3291452/)
@craneman - Nice! That'll save some bucks.