Thanks! The information on the joker valve's function to create a vacuum for the piston upstroke makes sense. I never thought that the joker was a good one way check valve slit or no slit. I used super lube at the spring commissioning to lube the inside of the piston were Peggy's excellent book. The base valve is new this season and it is installed with the "bump" up cause I checked. Sadly I can't get to my wast tank vent hose on my Hunter 31 to check for an obstruction without cutting and inspection whole in the cockpit. Hunter built the boat around the holding tank I think. Today I remove the wast tank clean out cap to make 100% certain that the tank is venting. I then filled my toilet to the brim with water from the bathroom sink. Yes I am pumping in the "Dry" mode. After 10 strokes I can hear water splashing into the wast holding tank. After 20 strokes I am sucking air. There is no back pressure on the pump. Within 2 minutes I had about a pint of water back in the bow. It never backfills above that level. Is removing the threaded tank cap a valid check to eliminate a blocked vent line? I am opening the tank to air.
Lubricating Manual Head
- Thread starter BayMan
- Start date
A few thoughts on grease.
- Superlube from Ace is Superlube Synthetic Grease. They also make silicon grease and a number of other things. The important thing about synthetic grease in this application is that it is easy on neoprene.
- Superlube from Ace is not silicon grease and it is not dielectric grease. It is a synthetic petroleum grease with Teflon added. Superlube does make silicone dielelctric grease, but that is a different product and Ace does not have it.
- Super lube is specifically not recommended for winches with low speed and high gear loading (this is in the tech sheets). They do make an extreme pressure grease that might be suitable, but a better choice is Lewmar winch grease or one of several synthetic industrial waterproof greases with extreme pressure ratings.
- Super lube is not nearly as washout resistant as Lanicote (lanolin by Forespar), Green Grease (Omni) and is mediocer in repeated testing for corrosion protection. It's real advantage is high temperature service... which is kind of irrelevant for seacocks.
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waste tank cleanout cap open will not vent, that is at the bottom of the tank, submerged. The vent line is at the top of the tank, allowing air in/out of the tank as fluid level changes.
Check the screen on the vent, I had the screen clogged with wax before. You can add water to the cleanout cap, place a finger over the vent for a second and release. You will build up slight pressure in the tank that way, and on release should get a good rush of air out the vent. Same goes for pumping out, if you cover the vent then release while pumping out, you should hear air rushing in the vent as you have created vacuum in the tank.
Check the screen on the vent, I had the screen clogged with wax before. You can add water to the cleanout cap, place a finger over the vent for a second and release. You will build up slight pressure in the tank that way, and on release should get a good rush of air out the vent. Same goes for pumping out, if you cover the vent then release while pumping out, you should hear air rushing in the vent as you have created vacuum in the tank.
That's exactly what ours did and turned out to be a "known design flaw". Search the forum for details. I contacted Jabsco and they acknowledged the problem and sent me a new pump. New pump works perfectly.
The only downside was that after shipping and import fees (came from Mexico) I only saved $4 vs buying a replacement locally.
Jerry, I don't know what year your boat is, but on my 1983 H31 the holding tank is in the v-berth, and the vent fitting on the hull is on the starboard side near the bow, a few inches under the toerail. Hope this helps.
My boat is a 2007 Hunter 31. The waste holding tank is in the aft berth port side. The vent line is visible from the cockpit port lazaret but no human arm is long enough to reach it to remove from the thru haul vent stem. I do not understand what Apex means by this "wast tank clean out cap open will not vent, that is at bottom of tank, submerged". My vent line is at the top of the poly tank. It seems that removing the cap would vent the tank. When pumping water into the tank the air would be vented out of the open cap just as a vent line would do if it was not blocked. Thanks
Apex is right...opening the deck pumpout fitting will not vent the tank because the pumpout line comes from the bottom of the tank and the tank vent also has to be a source of incoming air to replace contents as they're drawing. All that opening the pumpout cap can do provide an escape for any air above the surface out as new waste comes in instead of pressurizing the tank... If you wait until the tank has become pressurized to open it, a lot more than air will be pushed out.
So yes, opening the cap will allow you to fill the tank with water, but won't provide the air needed to allow a macerator pump to pull the water out.
Maintaining a vent line to keep it open is actually very easy: replace the "vent" thru-hull with an open fitting that you can stick a hose nozzle up against and backflush the vent line...and then do that every time you wash the boat.
So yes, opening the cap will allow you to fill the tank with water, but won't provide the air needed to allow a macerator pump to pull the water out.
Maintaining a vent line to keep it open is actually very easy: replace the "vent" thru-hull with an open fitting that you can stick a hose nozzle up against and backflush the vent line...and then do that every time you wash the boat.
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OK. Got it. I'm going to replace the joker again. I took a pice of rubber hose with a diameter slightly larger than the vent and blew air into the tank with the cap on and off. With the cap on I could not blow air into the tank and with the cap off I was able to blow air into the tank and presumably out the opened pump out cap. Hopefully that is a valid test to determine that the vent is free.
A much more reliable test: Have someone flush the toilet while you're next to the vent. If air comes out, the vent is open...if none does, or it's less than a full "blast," it's blocked, or partially blocked.