Jabsco Twist / Lock Head

[dman535]

My Catalina 27 has the original Jabsco/Par head in it. The unit is letting waste water back in the bowl and last night in bumpy seas it overflowed. I was thinking about replacing it what a Jabsco twist/lock unit.

Any general comments on the locking function of this head? Any suggestions on upgrades or changes to make to the factory plumbing (anti siphon? shutoff?)

Thanks

Derek.-

[MarkJ]

Sounds like you need a new Joker valve.

Weird name for the thing. They should really call it the silly twit brained valve.

By the way, Aft dunny got clogged a few weeks ago (subject of another post) the blackage was just near the outfall.. but when I was investigating I found that the Joker Valve had been previously put in BACKWARDS!!!!! It worked for us just fine for 18 months! And may have kept working but for me changing it out to a new one, installed correctly. The reverse one just had the reeds permanetly open a bit from the force of pumping, I spose!

So now I will call it the Silly Reversable Twit Brain Valve

[Vasco]

I replaced an old Jabsco with a new twist lock one. I don't know if it's just me but the new one lets water in when left for a week, not a lot but it does backflow. The old one was fine but I thought I had a problem and replaced it (it was the hoses not the head). I replace the joker valve every year or two in the old Jabscos and don't have problems.

[dman535]

Are there any concerns over the plastic parts in the 30 year old head breaking or cracking in trying to service them? That was kinda of my fear in digging into the old head.

[Vasco]

Check the barrel of the pump. This it where it usually cracks when old. If it's not cracked just replace the joker valve. This is a simple procedure. Just two large screws.

[Firehoser75]

Dman,
Some people don't understand how to properly pump out the head after use and that can contribute to the back flow. Certainly Jabsco heads are notorious for requiring servicing, in particular replacing the joker valves, so either do that or replace the head to the new "twist lock". I just bought a new twist lock, but I have yet to install it. The reason I bought it was the new head only cost $20-30 more than the "rebuild kit" and I am not far off needing a rebuild (or replacement).

Now, as far as pumping the head..... Pump in the wet position to remove the "products" from the bowl, then pump in the dry bowl position for a good number of pumps (up to say 50), depending on the distance from your head to the holding tank. This pumping action involving air, actually continues to move the sewage along the hose. If you stop too soon, the sewage and liquid can flow back and lay against the joker valve instead of making it all the way into the holding tank. If the valve doesn't seal perfectly, you will get some leakage. Also don't forget to periodically lube the pump with water proof lubricant to make it easier to pump and to reduce wear.
Hope this helps,
Tom

[Cheechako]

For the price, if yours is old, you might just buy a new Jabsco locking head. They aint perfect but they do work. Had the "latest version" on a few boats in t he past 10 years and no more problems than the older $800 bronze heads....

[Hurricane Harry]

If its old Id replace it with another new Jabsco. Not worth messing with, they are so cheap compare to the non wellbeing if it does not work.

Each season (we have seasons) we start up our Jabsco with warming a few litres of freshwater to have it run through the system. As well as at end of season same procedure. This will make most of the saltcrystalls disappear in system./Harry

[thinwater]

Keep a spare.

Latex gloves are not a bad idea, either. I keep them with the spare parts.

[dman535]

I had planned to do a joker valve. But now the toilet is not drawing in sea water. I am guessing the pump has given up the ghost. I don't think all the parts are available to service it - so I am going to pursue a new head.

Thanks to all that replied.

Derek.-

[Vasco]

The good thing is that the new Jabscos have the same footprint.

[Ocean Girl]

Have the Jabsco twist lock for a year now - no problems.
Erika

[Talbot]

If you have the old par brydon version - which looks the same as the Jabsco. I would seriously recommend replacing what is needed rather than a complete new jabsco. The old par brydon was built to a much higher quality.

[enovillo]

thinwater, where do you get the joker valve for $15? All I've been able to find is the whole service kit, which goes for ~$70. Is the joker valve a "standard" size?

[Vasco]

I use Raritan joker valves, some say they are better. You can get them here $15.95
Raritan Parts
WM usually has the Jabsco joker valves but they want $21 for them.