Valve, size 1&1/2" or 3 inch waste water size

[Wanderer]

Hello,
On our 2008 Cardinal we have 3 waste water valves, black water from toilet, grey water from toilet and grey from kitchen. One or all are leaking since when I setup and pull the cap I get some flow. Looking on replacements I find 1&1/2 as well as 3 inch.
I'm thinking grey's are 1&1/2 and black is 3" would that be correct?? Which would I have?

[B3KEYS]

You are correct regarding the pipe sizes. I have a 2007 and had the same problem. The easy fix is to purchase an external valve that connects directly to your drain outlet. This valve will provide additional protection against spills. If the problem becomes worse, you can always replace the offending valve.