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Dave W
05-11-2018, 10:19 AM
While dewinterizing, found that the two gray tank dump valves are tight, Not sure if it's the cable or the seals. I can probably spray the cables with silicone or similar at the water station. The valve - I see Thetford has a product but can't find locally. Wandering the 'net see that some have poured vegetable oil in the tank which supposedly works.

Anyone tried the veggie oil treatment? Tanks are completely empty and a couple cups or more would slosh up against the seal, especially if I left the tank valve open, empty, except the oil, of course.

notanlines
05-11-2018, 10:53 AM
Dave, like most things, it isn’t quite that simple. Your cables can only be lubed by pulling on the handles and moving them out a few inches and then spray your line of choice into the very, very tight space available until you believe some may have gotten to the appropriate area. And if you plan on vegetable oil to lube anything by sloshing around you need to put about a half gallon in each tank and then after a few miles add some water to raise the level of the oil. A couple cups won’t wet the bottom of the tank.

JRTJH
05-11-2018, 10:57 AM
Haven't tried vegetable oil, but we regularly pour half a cup of olive oil down our toilet to lube the valve/seals in the black tank. I don't think it would work as well on gray tanks because Dawn (or other dishwasher liquid) is formulated to dissolve oil and disperse it. That would prevent it from staying on the seals to lubricate them. Do a search for "EVOO" on this forum, there are some interesting threads complete with a couple of salad dressing recipes.

If you have Bowden cables (like the spring wound throttle control on your lawn mower) there is a cable lubricating tool available at any cycle shop. It's designed to "inject" lubricant inside the spring to help keep the cable moving freely. Easy to use and very effective. Costs about $5 at most cycle shops.

Dave W
05-11-2018, 11:31 AM
Dave, like most things, it isn’t quite that simple. Your cables can only be lubed by pulling on the handles and moving them out a few inches and then spray your line of choice into the very, very tight space available until you believe some may have gotten to the appropriate area. And if you plan on vegetable oil to lube anything by sloshing no around you need to put about a half gallon in each tank and then add some water to raise the level of the oil. A couple cups won’t wet the bottom of the tank.

The Walmart brand veggie oil is pretty cheap and I don't mind putting a bunch in the tank vs the pain of replacing a valve or two (valve is easy - the belly cover isn't)

Haven't tried vegetable oil, but we regularly pour half a cup of olive oil down our toilet to lube the valve/seals in the black tank. I don't think it would work as well on gray tanks because Dawn (or other dishwasher liquid) is formulated to dissolve oil and disperse it. That would prevent it from staying on the seals to lubricate them. Do a search for "EVOO" on this forum, there are some interesting threads complete with a couple of salad dressing recipes.



If you have Bowden cables (like the spring wound throttle control on your lawn mower) there is a cable lubricating tool available at any cycle shop. It's designed to "inject" lubricant inside the spring to help keep the cable moving freely. Easy to use and very effective. Costs about $5 at most cycle shops.

Shades of Giada and her cooking shows with EVOO

Dish liquid is also a choice for lube. I can see the suds coming down the vents as I roll down the highways and byways. Unfortunately, no staying power while the veggie oil will last at least a while

I've seen those motorcycle cable lubers and was wondering if they will work on an RV tank pull. Recall that these RV cables have a solid area about 6" long and not sure that I could get anything past the ferrule that bolts to the water cabinet unless I pulled it loose. Oh well for a few bucks. might be worth a try. Amazon - here I come --- again

travelin texans
05-11-2018, 01:26 PM
I've used the veggie oil in my gray tanks on occasion & use a cheapo dish or laundry soap in the black tank after/during draining/flushing, both work well.

kksfish
05-11-2018, 01:57 PM
Couple gallons of water, some darn detergent and small bottle of mineral oil- go for a drive to slosh around then allow to sit for a week worked for me!

Dave W
07-13-2018, 02:32 PM
Thought I should finally report back about this little problem.

I picked up a gallon of veggie oil at less then 5 bucks at Wally World. Half went in each gray tank. Mow the slide handle works with ease. I also bought a bottle of the Thetford gate valve lube ($12) but so far it's still sealed in the bottle though will get a try soon.

Cheap veggie oil works great and a bunch less expensive then the Theford:D:D

MattE303
07-13-2018, 03:21 PM
Thought I should finally report back about this little problem.

I picked up a gallon of veggie oil at less then 5 bucks at Wally World. Half went in each gray tank. Mow the slide handle works with ease. I also bought a bottle of the Thetford gate valve lube ($12) but so far it's still sealed in the bottle though will get a try soon.

Cheap veggie oil works great and a bunch less expensive then the Theford:D:D

so when you poured the veggie oil in, did you have the valves open or closed, or does it matter? I assume once you think the oil is in the right area, you want to open/close the valve several times to work the oil into the valve mechanism...

Dave W
07-14-2018, 02:45 AM
so when you poured the veggie oil in, did you have the valves open or closed, or does it matter? I assume once you think the oil is in the right area, you want to open/close the valve several times to work the oil into the valve mechanism...

I guess I should have 'splained my method. This is only how I did it. others may differ

- fully empty tanks with the valved closed
- pour in about a half of the gallon in each tank through a sink drain
- add a couple gallons or so of water for the concoction to slosh around
- drive to a campground (in my case it was just over 100 miles0
-- open one tank valve with the Thetford secondary gate valve at the outlet closed and let the line fill with the water and oil floating on it. Let sit for a while.
- Dump the first tank.
- Repeat with second tank.

The black tank didn't need the oiled up seals

This will push oil up the neoprene seal though not the cable

I forced some spray lube using that almost useless straw they supply past the handle end of the cable rod. A motor cycle cable luber may work but it will need to be modified to fit over the usual piece of 1/4" solid rod that extends out of the attaching nut. I bought one of those gadgets but haven't modified it yet though will (if I can find it:o).

Your success may vary though I am happy how our valves now work

MattE303
07-14-2018, 05:04 AM
I guess I should have 'splained my method. This is only how I did it...
<snip>

great! (tx)