Community Forums

cptmiker · 05-20-2011, 07:00 PM

Hello all

I have not been using my RV for a few months now but I start it every week. This week I started it up and it will not build any air pressure in the Air tank at all NONE. Gage reads 0 L. The air bags would not inflate at all and this usually happened after about 10min. I have looked and listened as well as I can at all air line connection. And can’t seem to find any air leak sounds I also spayed almost all connection with soapy water to see if there are bubbles. I know I need now air bags and this may be the issues but I can’t hear or see any leeks. Is there a way to test the compressor to see if it is working properly? This is an older MIDLAND N7602B the replacement for this is an EL850. The RV is a 1985 beaver with a cat 3208 Air brake it does not have full air brakes they are hydraulic. I ran the rig for 20 + min since it was out of air. Any help would be great BTW if anyone has any Gillig manuals for this year that would show the air system would be great.
Thanks
Mike.

Dixieray53 · 05-20-2011, 07:11 PM

Did it build up pressure everytime you ran the engine before this time? Bad Air Dump toggle switch? Just my shot at it....D

KIX · 05-20-2011, 07:31 PM

I'm with DixieRay.........i'm thinking an electrical switch. Sorry I can't be of more specific help

cptmiker · 05-20-2011, 07:53 PM

Yes it did build up air every time and held for about three to 4 days with slow leak. any idea where the air dump would be. It has an old HWH 400 series leving system that does not work. I have never been able to get the control panel to light up and haveing a hard time finding a replacment. This is my next project. I going to build my own switch pannel for the leveiling since HWH want 800. for a new panel and I cant find a used one. I did see 2 valved that look like electric with Manual purge valves on them mouned need the front of the air tank bay the back axle.

Mike Canter · 05-20-2011, 08:47 PM

If neither needle is moving on the tank pressure gauge my guess is that the air compressor regulator is stuck. I have read several posts where this has happeded to others. Several guys fixed it by tapping the regulator with a soft mallet. Even if you had a leak in the airbags you should still build pressure in one of the tanks. maybe not much but some. Did you leave the air tank drains open by some chance?

cptmiker · 05-20-2011, 09:55 PM

Thanks for the continued feedback. The first thing I checked was the Air drain valve, there are two tanks. One mounted in the rear and a smaller tank mounted in the front. I have also closed the Dump valves for the rear and Have not found one for the front. I did notice ride hight valve mounted on the front, but i dont think that are stuck open I dont think the can dump enuff air to not allow any air presure at all to build up. I did read the posts about taping on the Regulator Thanks for ponting that out "Attacted to the rear of the Air pump" right? with no seccsess. I was hoping there would be a test or a gauge I could hook directly to the output /regulator of the air pump to mesure output. Model =Midland N-7602-B SN#249 Got a colletors item here LOL. I was looing at maybe relacing the Regulator. I going to asum I hate that word the its a 105/125 cutoff.

Thanks
Mike.

cptmiker · 05-21-2011, 01:07 PM

OK just an update I started the unit today and ran it for 15min no air pressure build up on the gauges at all I manually 35 min to get it up to preacher. There are two air tanks one in the back I would guess about 10 to 15 gal and one in front about 3 to 5 gal. 4 air bags about 12in in diameter and 10 to 15 in tall in the rear and 7 to 8in in diameter in the front and about 10 to 12in tall. Would this be a normal amount of time to air up an empty system? Should I consider replacing the Air pump and or the governor or both? I am sure there is an air leak someplace since after 2 to three days the Air bags are depleted. I am going to time how long it takes to deplete the air pressure its at 120psi 5/21/11 at 11:45AM

Thanks
Mike.

cptmiker · 05-21-2011, 01:32 PM

Well its now 12:23PM 5/21/11 and the gage is down 10PSI and the front airbags look about 60% depleted. Where as the rear air bags look at about the right level. Strange. I am thinking there is a significant leak in the front airbags or the lines to the front airbags. It might even be the autoleveler valves.

bbeane · 05-21-2011, 01:38 PM

Mike, I doubt your air compressor is bad, there is nothing majic in the comp just valves and pistons. It does have an air gov. on it but you should be able to hear the air bypassing if it where open. the numbers you see on it 105/125 are cut in cut out setings thet can be adjusted where ever you want them usually 90/125. Now I beleave that comp is belt driven is the comp actually turning the pully is keyed on the shaft and has a nut to to hold it on make sure the shaft is turning. Follow the air output hose and see where it goes, if it goes to an air dyer see if you have air escapeing form the bottom of it. The dryer has an unloader valve and a purge valve that will cause these problems. Good luck.

cptmiker · 05-21-2011, 02:50 PM

Thanks for more feedback you guys are great. The compressor it rotating correctly and yes it is Belt driven No belt slippage and no strange noises coming from it. I believe there is a Dryer mounted under the RV. I will try to map out the air lines its a bit scary being under this thing. I wish someone had a Gillig diagram someplace they could share. I checked with Gillig and they want a whopping 300 bucks for the chassis manual

Thanks everyone keep any more ideas comming.

weaverworks · 05-21-2011, 06:45 PM

Mike

I had a similar problem with my Phaeton. Try holding the brake pedal in while the coach is airing up. It took several minutes, but then mine began airing up. The purge value was stuck open.....I believe from dusty conditions parked in Midland, TX

Good Luck

Paul

cptmiker · 05-21-2011, 11:40 PM

Thanks for the tip But i'm not sure what effect this would have since its hydraulic 4 wheel disk brakes.

Thanks
Mike

I belive that there is a sigificant leak in the front air bags or the lines. The front air bags have defated at this pint and the rear are holding. I wondering if there is anuther purge vavle that i missed closing for the air dump. But i cant find it anywhere. I'm not sure why just the front bags have defalted and not the rear there must be some sort of check valve in the system since there are two air tanks maybe the front tank is drives the front airbags I dont know at this point.

Thanks All.