Black Tank Valve Issue

[Dutch Star Don]

He was always rebuilding them because it was a home made tow truck. Ford truck with Oldsmobile engines that he drove like he stole them. Back then, 10% of the cars in his wrecking yard had Oldsmobile engines.

Back to the drain. Using vasoline or grease as a one time application to hold a seal in place is not going to cause it to swell. It's typically constant duty that causes an issue.

[Pexring]

I too would also replace the valve. You can buy seal kits, but it's the same amount of work to replace the seals as it is to replace the whole valve, so might as well do the valve.

[bruceisla]

Been a while but when I replaced mine it did not have O-rings ... it had seals that had different inner and outer surfaces. You needed to pay attention and not put them in backwards or you could cut the seal with the slide.

[gmarsha2]

Thanks to all the information and the tips. I now feel comfortable in proceeding(carefully).

[dutchstr3884]

I replaced both of my valves a year ago. Flushed the tanks well and then before removing the bolts and valves I took a large plastic trash bag, placed several cups of cat litter in it and then spread the bag below the valves. The cat litter and trash bag caught the small amount of liquid that came out of the tanks when they were removed. replaced the valves and bolts, pulled out the trash bag (with cat litter and trapped liquids) and tossed it in the
garbage can. Job done and everything clean.

[spinn]

Originally Posted by dutchstr3884

I replaced both of my valves a year ago. Flushed the tanks well and then before removing the bolts and valves I took a large plastic trash bag, placed several cups of cat litter in it and then spread the bag below the valves. The cat litter and trash bag caught the small amount of liquid that came out of the tanks when they were removed. replaced the valves and bolts, pulled out the trash bag (with cat litter and trapped liquids) and tossed it in the
garbage can. Job done and everything clean.

Great idea