I replaced my bad flush valve with this
SeaLand SE314349 Water Valve Kit by Sealand
from amazon.
It was a perfect match for my toilet which is in my 1985 hi-lo. Pain to install due the restricted space, but works perfectly.
Good luck with your other repairs. Stay COOL
steve
I rebuilt my Mansfield toilet flush valve today because, well, I am tight like that. LOL
NOT for the faint hearted. I "should have" taken a LOT more pictures of it as I disassembled it but eventually I figured it out. Actually, I should have replaced it with the above mentioned unit but I am impatient and wanted it NOW. (I have the time, just hard headed I guess)
Also, my valve has a male 3/8 flare fitting on it instead of the 1/2" FPT ? that I noticed online on the new valves. As it turned out it would not have mattered as I had to modify that line anyhow (read 2nd to last paragraph)
All "O" rings and main seal were found at ACE Hardware but the main shutoff seal had to be modified slightly by opening up the center hole from ~1/8" to ~3/8" by using a hole punch from Harbor Freight.
Cost was around $8 with tax.
I pulled the toilet to access easier and this made the valve testing much easier as I was able to adapt my water hose directly to the valve.
Also known to me was the shutoff valve leaking. I replaced that crappy plastic valve (I HATED this plastic lines in 1977-1979 when I worked on RV's) with a house type made for 3/8" soft/hard copper that I adapted to plastic fuel line for in/out. That line fit perfectly over the OEM plastic line and 2 hose clamps secured it on every junction. Only then did I notice a crack in the OEM flare fitting that attaches to the toilet valve. Another trip to ACE and I was up and running.
While I had this trailer in my shop I replaced both holding tank shut off valves as one or the other was leaking and I did not want to cut corners or waste time replacing 1 and then the other later. At least I KNOW the plumbing is tight now.
Thanks for the part # in the quote above Steve.
Rick