By Doug Swarts
We’re asked often about the proper method to lubricate a sticky RV dump valve. The RVers are usually referring to the black 3-inch gate valve on their black holding tank. In some cases the 1.5-inch gray valve gets sticky over time especially if the RVer is not using his RV full time. The contents inside the valve dry out causing the valve to stick.
PROPER METHOD OF LUBRICATION
Empty and clean your tanks by filling the tanks 2/3 full of water then dumping, repeat until the clear view fitting at the sewer ground inlet runs clear and free of particulate. Next, remove the valves from the flanges that hold them in place in the piping. Detailed instructions can be found here. (Note: These particular instructions are for our Drain Master electric valves where you can submerge your manual valve completely.)
Soak the valves in hot water with some detergent, making sure to leave the gates open. Periodically agitate the valve with the open or hole end down in the water – the idea is to remove the debris that collects in the body of the valve over time as the gate is opened to dump your tanks. When you feel the inner body of the valve is clean, remove and blow the inner valve body to remove any excess particulate that air pressure may loosen. Use Dow 111 synthetic grease or any non-petroleum grease and lubricate the SS shaft if your valves are the manual pull type. Close the gate and apply a thin coating of grease to both sides.
Remove the seals from the flanges and inspect both of the seals and the flanges for cracks or abrasion. If damaged, replace.
Apply a thin coating of grease to the seals and install them on the flanges. Holding the piping/flanges apart, insert the valve between the flanges being sure NOT to move the seals. Squeeze the flanges together and insert the four bolts and nuts. Make sure to hold the flanges tight against the valve during this process. Now finger-tighten the four bolts/nuts then use a wrench and tighten them to 20-inch pounds of torque OR no more than 1 1/2 full turns. DO NOT OVERTIGHTEN!
Install a grease zerk or access port so the valve can be lubricated without removing the valve. We have heard from a number of our customers that speculate this would be the answer to solve their problems once and for all. If you plan to attempt this we highly recommend you put the hole in the thickest part of the valve which is the TOP or where the SS shaft comes out of the body when you pull on it. The thickness will allow you to tap the body with enough threads to screw in a plug or grease zerk. Drill your hole in the center of the left or right side of the SS shaft hole, approximately 1/2” from the SS shaft.
If you use a grease zerk be sure you do not apply too much grease or the valve will be hard to pull and push open or close. A plug would work better as you can spray silicon spray into the hole then plug it again.
If your valves are installed in the tank piping with the handle lower than the 3 – 9 o’clock position when you open the valve the water inside will seep into the valve body (the root cause of sticky valves). IF possible, reposition the valves so the valve body is above the 3 – 9 o’clock position so the water that seeps into the valve body will drain back into the bottom of the pipe.
Most RVs with cable pull or rod-actuated valves are positioned in the side or 3 o’clock side of the exit pipe, allowing this contaminated water to lay in the bottom of the body and creating this issue over time.
Doug Swarts is a 25-year RV industry expert at creating and implementing revolutionary products for all RV waste management systems. His sound principles of RV waste management have led to a group of products designed to make the unpleasant task of dumping holding tanks more sanitary, safe and convenient for the end user. Doug is the founder of Drain Master.com Inc., Hollister, CA, which sells as well as installs Drain Master, Waste Master, 360 Siphon, HepvO and other RV waste-related products.