LP problem or not - Montana Owners Club

goin2themountains · 02-23-2009, 09:03 AM

Hopefully I can explain this so it's understandable. When I turn on the door side propane tank, close the access panel for a few minutes then open it back up, I get a whiff of propane. So, this weekend, I appropriated a small container of bubbles from one of the grandkids, and checked all the connections I could find through the access panel to this LP tank, without finding a leak. Now, in trying to think this process through, as oblique as my mind is, when a tank is empty, I get a little whiff of propane, so: might what I smell be from turning on the valve too fast, and having the safety valve kick stopping the flow? Just to test by experience, I closed the valve, reopened it very slowly, and repeated closing the access door for a few minutes, then opening and sniffing. In doing so, I could "not" get any whiff of propane.
Anyone think I am on the right track here, or am I so far off base it's not even funny?

ols1932 · 02-23-2009, 09:18 AM

You're on the right track. Propane leaks can occur almost any place. About 20 months ago, my wife could smell propane (I could not) but I couldn't find a leak using gas leak soapy liquid. One day the park manager came by to clean the fire ring and told us he smelled propane. So, I got out the soapy liquid again and this time I sprayed the regulator thoroughly. Found the leak! Propane was leaking out around the circumference of the level mechanism. Not a lot, but enough to make a bubble. I quickly shut off both bottles and went to my dealer and bought a new regulator. No leaks since.

If you have a leak, the soapy liquid should find it. But, as you say, it may just be associated with turning the bottles on. Did you spray around the valve on each bottle?

Orv

richfaa · 02-23-2009, 09:33 AM

You may not have a leak. There is a safety feature that will vent in the event of excess pressure buildup. I am as we speak in conversation with design engineers at Marshall on a suspected problem in our propane system. Your Marshall regulator should be a Model 254-00'

Check out www.shleggitt.com click on information page.

My system humms we are working on it with Marshall.

bsmeaton · 02-23-2009, 09:51 AM

I kept smelling LP on our 2003 and couldn't find it the first few times I bubble tested. Finally found it in the hardpipe to flex hose reducer before it crossed over to the other side.

Easy fix, hard find.

kilch123 · 02-23-2009, 10:07 AM

richfaa - please keep us posted. I get that 'humming' but only on the off door tank (that tank always has a frost line and icing below when in use as well) the other tank doesn't seem to do that, and I've swapped tanks, so it's not that???

goin2themountains · 02-23-2009, 10:21 AM

I will go back and spray the red regulator in the hard line on that side. I soaped all connections, but didn't think it would be in the regulator itself.

Orv, I disconnected the bottle, and reconnected, sprayed that connection, and all around the top of the tank as it's new. Nada.

My Father had mentioned maybe excess pressure blowing off, but I couldn't figure out why that would happen only when I open the valve, effectively reducing pressures.

At least it doesn't hummm, that would scare the snot outta me.

thanks for the hints, will update
Bob

richfaa · 02-23-2009, 10:42 AM

kilch123.. The humm is common is Keystone and Forest river products as they use the same system with "cost effective" parts. Mine also humms only on the side with the switchover regulator and stops when we switch to the other tank. They did inform me that the Red 16 psi regulator is not of the proper spec and 30 psi regulator is required. Marshall gave me some trouble shooting procedures to follow and some part numbers to check out. The guy at Marshall is talking engineer to me and although I am/was a ET he has to talk real slow in order for me to understand.
We are doing what he told me...will report back to him tomorrow and perhaps learn something???? They also said that Cold weather along with High demand will stress the "cost effective" parts and cause failures such as loss of propane flow.

Jim Jarvis · 02-23-2009, 11:10 AM

I had this hum for a while last summer and the smell of propane. It was coming from the regulator on the passenger side.

ols1932 · 02-23-2009, 11:28 AM

Humming? That's a new one on me. Have never heard ours hum in the almost nine years of daily use.

Orv

kilch123 · 02-23-2009, 01:38 PM

Thanks rich

Hopefully you can translate the tech-speak for me too!

racerjoe · 02-23-2009, 02:41 PM

Humming??? Is this name that tune???

richfaa · 02-24-2009, 01:31 AM

New safety features were introduced in early 06 so earlier years Will not have that problem. Sounds like a 300/400 cycle note and the name of the tune is "irritating"

Oh.. That red 16psi regulator is subject to leaking...check it very closely. Mine does NOt leak ut I am going to replace it with a 30psi anyhow.

racerjoe · 02-24-2009, 02:43 AM

You can be happy for one thing, You can still hear a noise like that!!! i thought after so many years of marriage and those words " did you hear that noise" you just become accustomed to it. Or is it just me??

Jim Jarvis · 02-24-2009, 02:58 AM

Quote:

quote:Originally posted by richfaa

New safety features were introduced in early 06 so earlier years Will not have that problem. Sounds like a 300/400 cycle note and the name of the tune is "irritating"

Oh.. That red 16psi regulator is subject to leaking...check it very closely. Mine does NOt leak ut I am going to replace it with a 30psi anyhow.

That red one is where I had the leak.

goin2themountains · 02-24-2009, 05:08 AM

Thanks all, I will check the red regulator tonight, if I get home before dark. If it's bad, I will have to balance whether is worth it to drive 400 miles round trip to the dealer, or replace it myself. So, the hummm is a harmonic vibration?

richfaa · 02-24-2009, 08:06 AM

I am OK with low frequencies. Can't hear high frequencies. What causes the humm is the problem. I will post the Marshall part number as soon as I get it for the red regulator. We are going to upgrade our propane system to the design specs recommended by Marshall, The folks who design the propane systems. We will post the information as soon as it is complete.

OK... Just put the phone down. Been working with Ed Lee, Sr
Senior application engineer, Marshall industries. These are the folks who design Propane systems. This is the guy who designs RV propane systems.This will ONLY apply to the systems that have the Red single stage 16psi regulator on the far side propane tank.

Symptom was low frequency humm on the switchover propane tank side.Would stop when switched over. More apt to occur when it is cold
or/and when there is high propane demand.You may also lose propane flow as the hum is not a good thing and safety features may shut of the flow.

First the red 16psi single stage regulator is just barely adequate and should replaced with the Marshall Single stage regulator part # C-6121 30psi. The red OEM 16psi regulator is subject to leakage and should be checked.

check the pig tail connection from the regulators to the tanks. The green twist on's. The CORRECT pig tail on the switchover side is Model A4 PN 40410-12 ..The PN on the far side is PN 424#20..They should boh be Marshall products.. The Marshall pigtail has a Stainless steel internal check valve. Others have a hard rubber ball check valve. The rubber check valve can cause high pressure problems and shut down.

There is a vent covered with a screen on the very bottom of the second stage of the switchover regulator.. It needs to be CLEAN...and
when it is humming you may be able to feel a slight pulsing motion and if you cover the vent with your thumb the humm will decrease or go away . That is verification that the second stage of the regulator and therefore the regulator is defective.

My pig tail connectors were of the proper type. I will replace the Red regulator with one that meets Marshall Design spc's. Next time we get the humm we will do the thumb over he screen check to verify the regulator. Ed Lee, Sr thinks the regulator may be bad.I don't know yet...

Check out the web site WWW.shleggitt.com and click on Information page... The slide show is excellent. Perhaps all this will make more sense.

bigmurf · 02-24-2009, 08:44 AM

Mind doesn't even have the Red POS.

bsmeaton · 02-24-2009, 08:53 AM

Like said above, Montana didn't start installing the red regulator until 2006.

The red regulator was installed to eliminate a prior problem of the tank safety valve closing when opening the tank too fast on the side opposite the standard regulator. The flow from the tank through the flex hose, across the front through hardpipe, then back into flex before the main regulator was sensed by the valve as an open line causing shutdown. The red regulator slows down the flow to prevent the safety valve from tripping. You can eliminate the red regulator, just open the far tank slower.

goin2themountains · 02-26-2009, 10:52 AM

Got digging around in the shed, and have a Marshall model 230 single stage low pressure regulator, which according to specs., runs an 11 inch column of water. If the OEM red regulator is discombobulated, I seem to have something to use in its place. Still trying to catch a night where I am home before dark to spray soap on the regulator to see if it leaks. I wonder, though, if the tank safety valve is just messing with me.

richfaa · 02-26-2009, 11:45 AM

The Marshall engineer said it was not a good idea to eliminate the red single stage regulator. There is more to the red regulator function that just slowing down the flow when the opposite tank is opened. He explained it to me but it was over my head. I spoke to Keystone today about why they used the 18PSI regulator instead of the system designed 30psi regulator. After a lot of back and forth the answer was "it meets RVIA spec's" Marshall did not deny that it did just that the system was designed with the 30psi regulator and did the job better. You know me I am going to bring my propane systems up to the manufacturer's spec's. Example Keystone and Forest river use the same system. Fleetwood uses the system as designed. I just want that Hummmmmm gone.

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