Holding tank pump out pickup location

[DaveK]

1985 43' Motoryacht, I am trying to determine where the pickup tube is located for the holding tank pump out. What I think is it, is under the hatch in the V berth floor. But due to the exactly location there is no way it could be pulled out without cutting the floor. I'll try to post a picture of what I think is the pickup tube later this evening.

 

[magnawake]

That's a scary thought but I hope you are wrong. Mine has an access by opening up the v-berth floor panel and lay it aside. If you pull up the carpet, going aft, you will see a piece of plywood that can be slide forward and removed. You can then see and gain access to the pick up tube. While your in there you might as well change the 3/4 full tube too. Mine is broke off too. Well rusted off prolly. I couldn't even get the plug unstuck. We pump out frequently so it's not a big deal. Also while you are in there you could change out the waste hoses too. I did have to cut a whole in the steps leading down to the galley for the work. I used the most expensive hose I could buy. The trident rubber hose with the green stripe. It's. Very flexible and easy to work around corners. That was a real pain too. Not an easy job. Come to think of it nothing is easy. I think for your job you should be fine without cutting anything.

 

[DaveK]

That's a scary thought but I hope you are wrong. Mine has an access by opening up the v-berth floor panel and lay it aside. If you pull up the carpet, going aft, you will see a piece of plywood that can be slide forward and removed. You can then see and gain access to the pick up tube. While your in there you might as well change the 3/4 full tube too. Mine is broke off too. Well rusted off prolly. I couldn't even get the plug unstuck. We pump out frequently so it's not a big deal. Also while you are in there you could change out the waste hoses too. I did have to cut a whole in the steps leading down to the galley for the work. I used the most expensive hose I could buy. The trident rubber hose with the green stripe. It's. Very flexible and easy to work around corners. That was a real pain too. Not an easy job. Come to think of it nothing is easy. I think for your job you should be fine without cutting anything.

Thanks Pate, never thought about pulling up the carpet, I'll be back down next weekend and will give that a try. We pump out regularly and it's not a problem but I would still like to fix it at some point.

 

[magnawake]

If you pump out regularly and it's not a problem then I must be missing something. I thought you couldn't pump out because the pump out tube going down into the tank was broke off. That's a common problem and not such a fun job to fix. If you are pumping out with no problem then your tube should be ok. Otherwise when you try to pump out it just sucks air through the vent. So what do you want to replace the pump out tube or the 3/4 light tube?

 

[DaveK]

When I pump out, I can't get the tank more than half empty according to the tank meter. I want to pull the tube and verify if it's rotted off or if the meter reads incorrectly.

 

[magnawake]

I would think the tank meter is messed up. Just a guess though. Most of them I've heard break off at the top. That way nothing pumps out and it's painfully obvious somethings wrong. You can get one of those Boro scopes from harbor freight and run it down one of the large hoses. I would try that first before tearing all that carpet up and floor panels. You could always use a Boro scope.

 

[Angela]

I had a problem with not being able to empty the holding tank. The OEM copper dip tube was corroded and broken off. It was about 30 years old. You can open the cap on the tank and take a peek to confirm whether your dip tube is toast or whether your gauge is. I'd bet it's the dip tube as the "full" gauge is quite robust (at least on my boat, anyway). Most of the time on these older boats, it's the dip tube. I rebuilt mine using all PVC so I would NEVER have to do that again. Well, almost. I have two holding tanks....the other one just started showing up "full" shortly after pumping out. I'm saving that one for Ed since I did the first one myself; next one is all his. Pascal did help breaking the seal on the tank. Here are some photos. If you fabricate a new dip tube, remember to cut the end of the PVC tube off at an angle so that the "point" touches, or almost touches the bottom of the tank.

 

[brico]

I just replaced the pickup tube on my 1980 37 Convertible, luckily my holding tank is a bit more accessible situated between the two engines. The original pickup tube rotted away and i replaced it with a PVC one. My problem was that the fittings were so tight that I needed to remove the whole brass cover through which the inlet, pickup, vent and tank level pipes are entering the tank. The biggest challenge was the backup ring inside the tank to which all screws go in to secure that brass cover. I hope I do not have to do this ever again. Luckily it is about 45 degrees here so it wasn't smelling too bad. Now I have to glass it all back to ensure it seals despite all the 3m 4200 I've applied.

 

[magnawake]

Where did your dip tube break? Was it right at the top or down a ways? If he can still pump out till the gage reads 1/2 then it must be broke off in the middle somewhere correct? Heck I can't even get the little plug out for the 3/4 light tube. We Niro scoped it and didn't see any tube so mine is broke off at the top. It's an easy fix if I could get they plug out. I know the light works.

 

[davidwigler]

Ang,

How did you empty the tank to work on it? Did you cut the new PVC tube to length and glue it in place, or did you stick something down the hole to measure the length?

 

[Angela]

Ang,

How did you empty the tank to work on it? Did you cut the new PVC tube to length and glue it in place, or did you stick something down the hole to measure the length?

My dip tube rotted off at the top of the tank, so it was slap full when I made the gruesome discovery. I was not able to empty the tank to work on it - lucky me. I used a small diameter wooden dowel rod to get the depth of the tank in order to know how long to make the dip tube. I used a bushing, I think, to screw into tank plate, then I used another one that had the dip tube attached to it. Everything screwed together. I bought a bunch of PVC fittings and then just played around until I came up with something that worked. Here is a photo of the parts laid out before I put them all together. The "clean out" cap you see is actually a port to attached an overboard discharge pump which I have, but never installed. One day....

 

[gbharrington]

You can fabricate a temporary pump out tube using a length of PVC that will slip through the fitting boss in the tank and then glue a 1 1/2" female adapter to one end and screwing an 1 1/2" hose nipple or a standard 1 1/2" pump out fitting to it. Then either slide your hose over the nipple and pump out through the deck fitting or bring the land side pump out hose aboard and attach to the pump out fitting on the tube. The latter was my choice.

 

[brico]

Where did your dip tube break? Was it right at the top or down a ways? If he can still pump out till the gage reads 1/2 then it must be broke off in the middle somewhere correct? Heck I can't even get the little plug out for the 3/4 light tube. We Niro scoped it and didn't see any tube so mine is broke off at the top. It's an easy fix if I could get they plug out. I know the light works.

My pickup tube broke at the top but it was also holed and prevented more than half of the tank to be pumped out. My level tube is in poor condition, but like you I am unable to remove the 3/4" square top plug to renew it so at this time i'll leave it. It may need heating up to soften the sealant/adhesive they have used when fitting it. Next weekend i'll go to my marina pumpout station and try my new pickup tube and see if the level light comes on (i know it works) when filled with water.....

 

[Colwyn D]

Just a photo of my solution 4 years ago. I should have cut the end at 45*, I've since had to go back and do it.
1 1/2" pvc roughed up and epoxied in.