Dump valves

[TOBYLB4]

My valves are glued. Black is glued right to the 90. Gray has about 2 inches of pipe out of 90. What are my options for getting them off without cutting? Can I remove the 4 screws of each valve and bolt back together? Thanks 

[Dr4Film]

Valves are not glued to the main dump pipes.

You remove the four screws and nuts from each valve, and with a little pressure to the side you remove the valve and rubber gaskets from in-between the two square flanges that remain.

 

[Doug and Nicki]

I noticed a post some time ago where a guy said he drilled a 1/8” hole in the shoulder of the dump valve above the handle. He would force machine oil into this hole periodically to lubricate the valve. He then screwed a small screw into the hole afterwards.  I wonder of doing this may help you get some lube in there to allow you to work the valve.

[MyronTruex]

Last picture shows lube hole location

 

The picture shows the valve assembly will move up and down as well. After replacing my leaking valve and finding this lube trick mine has lasted for many years and we full time. 

 

[Dr4Film]

I always leave the black valve open after the contents have been evacuated with the black back flush running. Then open the grey water last. There is lots of soapy water at the end to lubricate both the black and gray valves. I then close the black valve followed by the grey valve.

That procedure has worked for 20 years without having any sticky valve problems.

[Karl Hampton]

I have been using this the past couple of years and it seems to help.

Thetford Drain Valve Lubricant
Usage:
1.Normal Lubricating Procedure: After emptying holding tanks,close valve(s), pour 1/5 botle into each holding tank
(Toilet & sink/shower), Use holding tank as usual.

2 Sicky Drain Valves: Pour 1/5 botle into each holding tank
Containing4 gallons of water. Mix by driving or moving Venicie. Open and close valvels) several times, keeping as
much water in tank(s) as possible. Tanks are now ready tor nomal operation.
Use markings on label to measure.
NOTE: various mechanical problems may result in dificuft valve operation which cannot be corrected by use of the \uonca
For best results, use Drain Valve Lubricant routinely. Use n
uncion withtheThetordfamilyofholdingtank aditves. Store below 100°F 
KEEPOUT OF REACH OF CHILDREN.
CAUTIONC: contains a non-toxic surfactant. Avoid eye contact.
FIRSTAID: In event of eye contac., rinse eyes with water for 15 minutes.

[WillGee]

On 1/1/2023 at 6:33 AM, Doug and Nicki said:

I noticed a post some time ago where a guy said he drilled a 1/8” hole in the shoulder of the dump valve above the handle. He would force machine oil into this hole periodically to lubricate the valve. He then screwed a small screw into the hole afterwards.  I wonder of doing this may help you get some lube in there to allow you to work the valve.

I have done this procedure and has worked for me 

[Tom Cherry]

39 minutes ago, WillGee said:

I have done this procedure and has worked for me 

At least once a year, I lubricate the valve stems with silicone…..same thing for my Roadmaster TOW BAR (per the instructions).