'78 20' Minuet repair question: grey/black water drain valves
I don't know whether your '78 Minuet will have the same arrangement as mine, but on mine there is a 3' wide section of the belly pan that is held on by sheet metal screws creating an access panel to service the rear plumbing. It has been required on a regular basis due to the Minuet's minimal ground clearance creating issues with service station entrances and exits.
I have left my plumbing repairs to Ace Fogdall RV, but have had one ocassion where it was necessary to re-install the access panel as it dropped down in-transit. Once the access panel is down, the plumbing is accessible - - awkward to reach at best, but accessible. The valves are up against the floor boards since both the gray and balck water tanks are mounted above the floor.
Kevin D. Allen
WBCCI (Lifetime Member)/VAC/Free Wheelers #6359
1964 Overlander International/1999 GMC K2500 Suburban (7400 VORTEC/4.11 Differentials)
1978 Argosy Minuet 6.0 Metre/1975 Cadillac Eldorado Convertible (8.2 Liter V8/2.70 Final Drive)