Sticking waste valve

[rjohnsonnm]

Is there some sort of lubricant that can be used in the black tank to lubricate the dump valve before it gets too hard to operate. I was thinking perhaps some vegetable oil added to the black tank occasionally might keep it loose (pardon the pun). I haven't seen anything on the retail market to do this but with all the knowledge on this site I figure someone has figured it out.
Thanks,
Ron

[chevman]

I have used vegetable oil a couple of times. Empty the tank and pour one gallon into the toilet and let it sit. Then be ready to pull and push quickly before the oil has run though. I think you might have a cable system and we have a direct in and out so I hope this will work for you as well as it has for us.
chevman

[ldevries]

FWIW... I got tired of the hassle with cables and installed 12v electric dump valves on both the waste and gray water tanks

[Motor31]

I'm assuming you have a cable operated valve. It's sticking because of the cable not a sticky valve. Use some lube on the ends of the cable. The handle end and then inside the sliding basement door the valve end is located on the same side of the trailer as the handle. Apply some spray lube to there and it should get easier to operate. In my case I did away with the cable entirely 4 years ago and just use a handle operated valve. Since it's right there at the back of the sliding door it's no big deal to operate it to drain the black tank once a week. I'm dreading having to replace the grey valve as I'll have to either go electric or use another cable system. It's located under the trailer in that big black plastic bulge where the sewer pipe enters the belly.