Replacing Top Valve Gasket in Jabsco Manual Marine Toilet

If you're unable to bring water in to flush your manual marine toilet, then you may need to replace the top valve gasket. Here we show you how to replace the top valve gasket on the Jabsco Twist 'n' Lock manual toilet using kit 29042-0000.

Jeff: Thanks for tuning in to I'm Jeff Lander.

Mike: And I'm Mike Irving.

Jeff: And today, we're going to be talking about manual toilet having a problem bringing water in. When a manual toilet has trouble with priming, it can usually be isolated to the top valve gasket, which is located in the upper quadrant of the pump assembly located between the six screws right next to the pump handle.

Mike: One way to test the top valve gasket is to take the inlet hose from a toilet and put it into a bucket of water. If you can prime from a bucket of water, then most likely it's not the top valve gasket. If you can't pry them from a bucket of water then there's a high degree of certainty that you'll have to swap out the top valve gasket.

Jeff: This is a fairly simple replacement, as all you need is a flathead screwdriver and an empty bucket. The flathead screwdriver removes the six screws at the top of the pump assembly, and the empty bucket is for any residual water in this hose line.

Mike: Now as a little tip, make sure you leave the selector lever off to the left-hand side. That's going to facilitate taking the unit apart.

Jeff: Now, before you disassemble, you'll want to make sure that you have replacement part number 29042-0000 available. Again, that's the replacement part number for the top valve gasket as well as the spring. Now that we've taken the hose off and made a mess, it's time to remove the six screws from the valve cover. Again, very important to hold on to these because I've had several people lose them in the bilge or overboard before. So again, keep good care of these screws. Now before we lift off, again, like we said earlier, make sure the lever selector is open to the left or in the right pole position.

When removing the top valve cover, remove it slowly because there may be some residual water in the cylinder. Now that we have it off, the top valve gasket is exposed.

Mike: Always remember to wear gloves because the inside of the cylinder does come in contact with human waste. Just a precaution to hold on to.

Now, with wearing gloves, you’re going to go ahead and take off this top valve gasket. Go ahead and discard this unit now. If by chance this little piece comes up, always remember the cut out goes off to the left-hand side and just sits loosely inside there.

Jeff: Replacing the top valve gasket is an easy repair as you can only go on one way. This little cylindrical opening fits over the pump tube. This brass weight on the left sits on top of the top valve seat. And this little brass weight on the right sits over the inlet. As we put it down, we put it down flat over the six pillars, pushing down to make sure it's flat.

Mike: In the kit, you're going to have the top valve gasket and a little spring. That little spring sits right on the post inside the top valve cover right above there. And what does, it just assists the top valve gasket, making sure one of the valves stays closed.

Jeff: Now that the gasket has been swapped out, it's time to put the pump assembly back together. As I'm putting the pump assembly back on it's important to leave the lever selector in the wet bowl position, just like the way we removed it. When putting it back in, slide it down slowly and make sure the two halves mate together.

Mike: When you're putting the six screws back in using flathead screwdriver, tighten them down, but don't tighten them too tight. The big thing is you want to make sure that they’re snug, but you don't want to strip out the plastic. Once these are all in and tightened up, give the toilet test and you should be good to go.

Well, now that we've got this all back together, go ahead and give it a try. You should be good to go.

Jeff: Thank you for watching jabscotech. I'm Jeff Lander.

Mike: And I’m Mike Irving.

Jeff: Happy boating.