About a week ago the DW was vacuuming the interior and wanted to extend the stairwell cover. Instead of closing like it had a few minutes earlier, the cover made a funny noise and would not extend. The cover can be extended or retracted from two different locations; one switch near the driver's chair and one switch near the co-pilot's chair. I was under the impression the stairwell cover is electrically operated. Would appreciate any help in troubleshooting this problem.
Needs air pressure to operate
The stairwell cover operates off of air pressure. Do you have pressure in your air tanks?
Scott, You're a step ahead of me !
We had an issue with that thing, too. Our resolution was some silicone spray on the slide runners. That worked for some time. Then, we had to remove the silicone and it has been working, as should, since then.
Thanks for the replies. Checked my dash air pressure gauges. The top gauge (front air) showed ~ 50 psi and the bottom gauge (rear air) showed ~ 100 psi. When we parked in our campsite I drained the wet tank. I reviewed the Air Schematic drawing and see that the main line from the wet tank to the front and rear tanks contain 1-way valves which are to prevent air leaking back into the wet tank. Since the front air tank PSI is significantly down, I can only presume the 1-way valve in the front tank has failed. The front tank also supplies air to the stairwell cover. When I started the engine and let the air system pressurize, the step cover started working again. :-[ We have an appointment at MOT in February to replace the closet room air seal, so will add replacement of the 1-way valve to the WO. Coach bucks, coach bucks!! Where does it end? :D Thanks again for the help.
The step does work off the front tank, mine comes on around 70psi, you can hear it engage at that psi.
No reason to blame the check-valve as lots of things can cause the tank to lower pressure.
Dave, as Barry stated, it could be several other spots for leaks. Grab a squirt bottle of soap suds, put on some dirty clothes, raise the coach, set your safety stands, and spray away. Check every connection and watch for bubbles.
I found seven leaks at connections, as well as the small regulators. Since fixing those, I can go several days without losing much air.
You'll probably never be 100% leak free though!
Both norgren valves and their respective regulators for the step/cover are notorious for leaks. They live behind the "box" that is your entry steps. The rod that moves the step cover in and out is also known to leak where it enters the cylinder. I would consider these the lowest hanging fruit when hunting for leaks because they're very easy to get to.
Eventually you'll run out of low hanging fruit and it'll be time to rebuild your six pack(s).
98 U320. Which norgren valve when looking at them controls the step cover? Left or right?
I can't remember off the top of my head but if you have long arms, you can reach the forward most regulator (left) without crawling under the coach and shut it off to see what quits working. As I type that, I want to say that valve controls the entry step and vacuum generator for dash air.
As stated above, there can be several explanations for the 2 dash air gauges reading different pressure, especially after the coach has been parked for a while. You are correct, however, in your understanding that this pressure reading difference
might be caused by a leaking inlet check valve on one air tank. If you wish to spend a little time and effort, you can test your "faulty inlet check valve" theory by conducting a simple trouble shooting routine that eliminates the "parked for a while" time variable.
1. Run engine until air compressor cut-out (air dryer purges). Shut off engine. The wet tank and both brake tanks are now at the same exact pressure (approximately 120 psi).
2. Check (record) the reading on both dash air pressure gauges.
3. Open the water drain valve on the WET tank (see air system schematic), and allow pressure to bleed off to zero.
3a. What came out of drain valve? Dry air is good. Water, or oily grey "mud", or dry white powder is not so good. Time to service air dryer.
4. Check (record) the reading on both dash air pressure gauges.
5. If both dash gauges read the same pressure in step #2 and step #4, then the inlet check valves on the respective tanks are good. :thumbsup:
Clarification: With "good" check valves, the "front" and "rear" air tanks should not
immediately lose any pressure when you drain the wet tank.
6. If either, or both, of the dash gauges lost pressure (in the few minutes) between step #2 and step #4, the inlet check valve on the respective tank is faulty, and should be rebuilt or replaced.
If it turns out you have one (or two) bad check valves, they are not super expensive. Changing them out is not complicated, but can be somewhat difficult depending on how easy it is to get a wrench on the valve.
If they are OEM and have never been removed or replaced, they can be very TIGHT.
Part Number Collection (https://www.foreforums.com/index.php?topic=11472.msg225768#msg225768)
The step slide cylinder is difficult to replace, and there is no reason to always have the cylinder pressurized in open or closed position. We, like others have added a step slide air shutoff valve that is electrically turned off after moving step slide open or closed. Our idea is air pressure may eventually cause cylinder to leak and for very long periods of time step slide is either in open or closed position.
Valve is 3-way and when off it allows captive air pressure to release.