After looking high and low for a new valve and technical information regarding the lower valve on the firewall (K910026) I called the company in Canada that distributes the valve for Prevost. They have that valve back ordered with no idea when Norgren will ship any and they don't have any technical data on the valve. I determined that this valve may work https://www.norgren.com/us/en/detail/k41ea00ks1ka2 but it has a slightly different internal part. I'm not sure if I want to experiment with replacing it but at this point I only have one other choice. Radwell International can repair the valve. They offer no guarantee at $387.85. that includes a rush of $100.00 to have it back in 10 days. I'm on a waiting list to get the part from Prevost in Sommerville, NJ. Liberty Coach is also on a waiting list. I wonder how many people have a coach sitting useless waiting for this part!