CONNECTING TWO LP TANKS ON EARLY DISCOVERY MOTORCOACHES
The purpose of this article is to explain how to connect the Generator LP tank and the Coach LP tank on early model Discovery motorcoaches. Through the 1998 model year, the D only came with an LP generator. A diesel generator was offered as an option in 1999. Starting with the 2000 model year, the diesel generator became standard. This article is NOT applicable to those of you that have a diesel genset.
The main advantage of connecting the two LP tanks is that your COACH has access to the 24 gal coach LP tank and the 40 gal generator LP tank (both are water capacities). Note that this will not extend the available LP for your generator, mainly because the generator uses liquid LP and the coach uses vapor, and it is a very slow process for the propane to transfer to the generator LP tank. However, this modification is very beneficial as you can use your 40 gal generator LP tank to provide LP to your coach appliances. This allows me the freedom to wait until I find a good price on propane as I rarely use the generator extensively.
There are several ways to connect the LP tanks. The easiest way is to use the Marshall Brass Extend-A-Stay as you will not have to drain either LP tank. Here is a list of parts that I needed for my installation with my existing Extend-A-Stay:
For all pictures below, click on the thumbnail for a larger view.
Figure 1 shows my LP bay in my 98 36T prior to the conversion, but with the Marshall Brass Extend-A-Stay installed.
Figure 2 shows the completed conversion.
Figure 3 shows the original Generator LP tank bleeder valve.
Figure 4 show the T added at the Generator LP tank bleeder valve
Installation Procedure (with the Extend-A-Stay)
If you are not confident in what you are doing, have a professional install it for you!
Total cost for parts was approx $40.
Installation Procedure without and Extend-A-Stay
If you are not using an Extend-A-Stay, you will have to make sure that your coach LP tank is empty as you will be removing the bleeder valve and installing a T as you did at the generator bleeder valve. The hose will connect at this point instead of the Extend-A-Stay.
Use the ball valve and the ON/OFF valve on the coach LP tank to determine which LP tank you are using to provide LP to your coach. If you leave the ball valve open and also open the valve to your coach LP tank, the two LP tanks will tend to equalize. I almost never do this. I always use my coach LP tank first and then switch over to my generator LP tank when my coach tank is near empty. When filling either tank, close the ball valve.
A WORD OF CAUTION
The legality of this modification is unknown, so do it at your own risk.