Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Elliott on September 16, 2021, 08:42:50 pm

Title: Step cover / Air step explained
Post by: Elliott on September 16, 2021, 08:42:50 pm
Could one of you please refresh my memory on what the two valves behind the entry steps are in charge of?

I THOUGHT the one closer to the front of the coach was for the air cylinder that moves the step cover and the rear one was for the fold-down air step.

However, I shutoff both valves and can still see/hear air leaking from the old norgren valve (see picture) and both the step cover and fold-down step still function when closing the door or hitting the switch for the cover. It's been a while since I messed with these valves but I *thought* that shutting them both off would prevent operation of both cover and step.

Unfortunately the air diagram I have just dead-ends before the valves in question so I'm having to reverse engineer this.

My ultimate goal here is to shut them off until I can get a 12v valve put in on the feed line so bonus points for you if you can recommend a 12v valve and tell me where/how you mounted it to the chassis.
Title: Re: Step cover / Air step explained
Post by: Pamela & Mike on September 16, 2021, 08:52:35 pm
On our regulators if they are cranked all the way clockwise (like the1st.  pics. states) then they are wide opened no matter what the gauge reads.

Mike
Title: Re: Step cover / Air step explained
Post by: Cape Bretoner on September 16, 2021, 08:54:43 pm
That coach of your Elliott ever clean looking underneath that coach never been up North
Title: Re: Step cover / Air step explained
Post by: folivier on September 16, 2021, 08:57:02 pm
Those are pressure regulators, not valves.  Like Mike said, a regulator will be at highest pressure when the knob is turned all the way clockwise.  Turn it counterclockwise (or anticlockwise for our British friends) to reduce the pressure to 0.
Title: Re: Step cover / Air step explained
Post by: Elliott on September 16, 2021, 08:59:20 pm
 :headwall:

This is exactly why I mentioned which direction I turned them; just in case. Thanks guys.

Still looking forward to insight on the 12v valve
Title: Re: Step cover / Air step explained
Post by: Pamela & Mike on September 16, 2021, 09:10:46 pm
Still looking forward to insight on the 12v valve

Please expand on the project as to what you are trying to accomplish.. Are you just trying to add another norgren valve for some purpose?

Mike


Title: Re: Step cover / Air step explained
Post by: Elliott on September 16, 2021, 10:04:00 pm
Please expand on the project as to what you are trying to accomplish.. Are you just trying to add another norgren valve for some purpose?
I'm going to add a cheap 12v solenoid to the airline that feeds both norgren valves. I'll switch it on when in travel mode and otherwise have it turned off when parked so the norgren valves and air cylinder don't leak all my air out.
Title: Re: Step cover / Air step explained
Post by: oldguy on September 16, 2021, 10:08:31 pm
The valve without power sends the air to the cylinder or cylinders to extend or retract
the cylinder or cylinders depending on how they are plumed and when 12 volts is
applied to the valve it allows the air to be released and send air to the opposite side
of the cylinders.
Title: Re: Step cover / Air step explained
Post by: oldguy on September 16, 2021, 10:14:05 pm
The valve for the step should be plumed with the no 12 volts with the step
down and the other valve should be plumed with the slide in with no 12 volts
to the valve. On mine the front Norgren valve is for the step slide.
Title: Re: Step cover / Air step explained
Post by: Pamela & Mike on September 17, 2021, 06:52:15 am
I'm going to add a cheap 12v solenoid to the airline that feeds both norgren valves.

Ellliott,

Barry has a complete parts list and how to for what you are doing.    I will need some time to find his post. If Barry sees this he will chime in also.

Mike

I think this is what you are looking for.
Step slide air shut off valve to preserve cylinder (https://www.foreforums.com/index.php?topic=22226.0)
Title: Re: Step cover / Air step explained
Post by: Peter on July 09, 2022, 09:49:18 pm
Reviewing this post brought me some work on the norgren units controlling the step cover.
After reading your article Elliott I got under the coach to check on the norgren units as my stair cover has never worked.  Fooling around with the pressure regulators resulted in me getting it working again (hurrah).
I noticed while adjusting the regulator that the step cover leaked a bit so I discharged all the air from the the front brake tanks (left tank drivers side..right?)  and took the connections apart, and put on thread sealer and re connected them.
All seemed good as I could not get it to leak while soaking it with bubble solution
I left it for about 2 full days and noticed my step had fallen ( I have the the rework done to keep the step up with the engine off). So I check my air gauges and the front is down to about 30 lbs while my rear brake is still good at about 100
Is there something I am missing?  Is the front left brake tank the only source of a air and air lines to the step/stair cover? 
OR do I disconnect the original air leak spot connections and start again?
Title: Re: Step cover / Air step explained
Post by: Old Toolmaker on July 10, 2022, 07:03:49 am
Sources for 12VDC solenoid valves.

Automation Direct is more user friendly than Festo.

https://www.automationdirect.com/adc/overview/catalog/pneumatic_components/basic_directional_control_solenoid_valves

But Festo is the go to source for power users.

https://www.festo.com/us/en/e/festo-solenoid-valves-id_412576/
Title: Re: Step cover / Air step explained
Post by: Peter on July 10, 2022, 07:09:40 am
Old Toolmaker
so you are suggesting I require solenoid valves? I think my norgren units are ok as they do not leak when I spray them
Peter
Title: Re: Step cover / Air step explained
Post by: Old Toolmaker on July 10, 2022, 10:33:37 am
Old Toolmaker
so you are suggesting I require solenoid valves? I think my Norgren units are ok as they do not leak when I spray them
Peter

The hair on the back of my neck rises when people refer to air valve by a brand name.  Bendix set the stage for air brake nomenclature, and calling the valves that operate your step and door Norgren valves just makes it unnecessarily difficult to source replacement parts.  What I'm trying to teach is that solenoid valves are a commodity item available from the catalog.

But I gotta ask you Peter: Are you checking just the in and out connections?  It's possible that the internal seals may be leaving this world for the choir invisible and air may be leaving via the exhaust port, or even through the air cylinders themselves.

FWIW Automation Direct was my go to source for "electronics" and actuators until Quality Control insisted on using Allen Bradley "because they're ISO certified," and "Management" wanted Festo because, well, they're German.  Automation direct is not only great for beginners, but you only buy what you need.  Allen Bradley is great for proprietary content than changes on an annual basis.  Festo is great if you want to build a pneumatic computer operating actuators in an intrinsicly safe mode for hazardous enviroments.
Title: Re: Step cover / Air step explained
Post by: oldguy on July 10, 2022, 11:45:26 am
Make sure when testing for leaks that you check the exhaust ports. That was why I changed
mine as they were leaking from the exhaust posts.
Title: Re: Step cover / Air step explained
Post by: Peter on July 10, 2022, 03:07:13 pm
Ok I will check the exhaust ports. I should be able to spray them and see leakage correct?
Title: Re: Step cover / Air step explained
Post by: oldguy on July 10, 2022, 05:51:23 pm
I believe that's how I found them leaking.
Title: Re: Step cover / Air step explained
Post by: Elliott on July 10, 2022, 09:05:37 pm
Ok I will check the exhaust ports. I should be able to spray them and see leakage correct?
Yes, but make sure you have over ~75psi in the front tank so that the protection valve opens up and delivers air to that part of the system.
Title: Re: Step cover / Air step explained
Post by: Peter on July 10, 2022, 09:29:58 pm
Elliott,
yes I wait until the d2 Governor kicks in, which is about 125 LBS.

Peter,
Do you have an idea on where to purchase the exhaust ports in Canada?
Lots for sale in a variety of places states wise but unsure where they are located for purchase in Canada.
Peter
Title: Re: Step cover / Air step explained
Post by: oldguy on July 10, 2022, 09:32:20 pm
If it is leaking out the exhaust ports the valve needs to be replaced.
Title: Re: Step cover / Air step explained
Post by: Old Toolmaker on July 11, 2022, 09:23:07 am
Elliott,
yes I wait until the d2 Governor kicks in, which is about 125 LBS.

Peter,
Do you have an idea on where to purchase the exhaust ports in Canada?
Lots for sale in a variety of places states wise but unsure where they are located for purchase in Canada.
Peter


You'll need to find your local source for industrial supplies.  Festo is an international company, but it's fast pitch hardball compared to Automation Direct, and their catalog is best deciphered for the new-bee by one of their sales engineers.  Unless you really love catalogs.
Title: Re: Step cover / Air step explained
Post by: Barry & Cindy on July 11, 2022, 07:37:35 pm
If it is leaking out the exhaust ports the valve needs to be replaced.

OR removed, taken apart (after all it was going to be trashed), easily cleaned, lightly lubed and put back together for a probable long life without concern for handling the different mounting issues with a replacement.

Also, for the inside step slide, since it does not need constant air pressure to hold it in either direction, think about installing a 3-way valve to relieve air pressure after the slide is moved in either direction, to greatly increase life of air cylinder piston, which can be difficult to replace.
Title: Re: Step cover / Air step explained
Post by: Elliott on July 11, 2022, 09:58:38 pm

Also, for the inside step slide, since it does not need constant air pressure to hold it in either direction, think about installing a 3-way valve to relieve air pressure after the slide is moved in either direction, to greatly increase life of air cylinder piston, which can be difficult to replace.
If the right Norgren valve is leaking, it already does that :-)

Agreed though, The leaking cylinder is a pain. I ended up installing a solenoid before that entire corner to prevent leak down because it was much easier than replacing that cylinder.
Title: Re: Step cover / Air step explained
Post by: Peter on July 12, 2022, 03:31:55 pm
So I found the step norgren upper exhaust is leaking. Is it feasible to clean/ overhaul the norgren to get me by for a while. And what is the process?
Title: Re: Step cover / Air step explained
Post by: oldguy on July 12, 2022, 05:28:26 pm
I took mine apart hopping I could change the O rings on the plunger but the whole
plunger is rubberized so I couldn't fix it. Do you have a place like Pacific Controls they
may have something that will work.
Title: Re: Step cover / Air step explained
Post by: Peter on July 12, 2022, 07:59:47 pm
Oldguy
Found a norgren brand valve (new style...a bit longer) at Allied electronics.  175cdn all in with shipping
Title: Re: Step cover / Air step explained
Post by: oldguy on July 12, 2022, 09:18:54 pm
In reply #11 Old Toolmaker shows you can by them for a lot lest money.
Title: Re: Step cover / Air step explained
Post by: Old Toolmaker on July 13, 2022, 09:17:46 am
In reply #11 Old Toolmaker shows you can by them for a lot lest money.
I never said less expensive, oldguy, I want to show that 30 year old pneumatics can be replaced with greater ease than hunting up NOS components.  For instance, regarding the air cylinder for the fuel injector arm: I've sketched out a replacement from the Festo catalog that functionally will drop right into place.
Art
Title: Re: Step cover / Air step explained
Post by: Peter on July 15, 2022, 11:08:33 am
So ordered a valve from allied electronics(Canadian distributor)  and also order a few exhaust ports to replace them as well
Just so I am on the same page, I realize with the different size of the replacement I will have to slightly relocate it but my question is in the removal of the original valve.  The powered three prong connector.... Do I just loosen the screw in the top to remove it or is there something else I am missing here.  Just don't  want to break something in the removal. Also I presume I can use the same plug and do not have to re wire the new one???
Peter
Title: Re: Step cover / Air step explained
Post by: Peter on July 19, 2022, 09:40:35 am
Buying a new valve as suggested by many instead of attempting to repair the old one

To remove the old valve seems simple enough..remove the through bolts into the step cavity, but to release the electrical plug do I just loosen the screw at the top?  Also when I remove the old norgren and install the new one it comes with a new "electrical connection cap". Can I use the old one so I don't have to transfer wires and just plug it into the new valve?
Title: Re: Step cover / Air step explained
Post by: Peter on July 22, 2022, 05:43:11 pm
tried asking a question on the removal of the electrical connection for the valve.
If anyone knows of the sequence to remove the electrical connection (without removing the wires ie: does the screw on the top loosen of the top and the cap comes right off) i would appreciate it.
Just looking online....would the below work for the valve as well????

1/4" NPT 5 Way 2 Position Pneumatic Electric Solenoid Valve DC 12 V:... (https://www.amazon.com/gp/product/B00VU1BVDI?ref=em_1p_0_im&ref_=pe_2313350_653278760)
Title: Re: Step cover / Air step explained
Post by: Jan & Richard on July 22, 2022, 05:54:09 pm
Sorry for not responding earlier.  On my '99 U320, there is a phillips screw on the end of the plastic electrical connector.  When this screw is removed the connector should come right off. 

Richard
Title: Re: Step cover / Air step explained
Post by: Peter on July 22, 2022, 06:07:04 pm
Jan and Richard,
Thanks so much for the info!  I did not want to proceed and wreck something without confirmation.
Peter
Title: Re: Step cover / Air step explained
Post by: Jan & Richard on July 22, 2022, 06:19:00 pm
I came close to breaking my electrical plug trying to pry and twist it off before I noticed the Phillips screw.