Head vacuum pump runs continiously

[Knot Sure]

I have a 1987 390EC. I would like to find out where the vacuum switch is located, that shuts the pump off, before I start taking things apart. There seems to be plenty of vacuum at the head but the pump never stops. Any help would be appreciated.

 

[rcknecht]

It is is a vacuflush, it could be rubber gasket around the ball drain that is leaking. Is the water in the toilet getting sucked dry? Should also be making a noise...

 

[Knot Sure]

The water is staying in the toilet fine. And there's no noise.

 

[Redhook98]

Could be the duck bills then. If not, then your on the right track by checking out the vacuum switch next. About 97% of the vacuum related issues with Vacuflush's are the ball valve gasket and the duckbills.

 

[NoThanksDad]

Knot,

I had a very similar issue (although on a different SR model). I did a quick search to try and find the thread (to no avail), but then remembered that I had copied the helpful post to "word" and brought it out to my boat last year when I was fixing mine. Below is the information I that got here on CSR. I can't take credit for the content (especially if it works for you).

Best of luck
Joe


"The third and last most common Sealand Vacuflush marine toilet problem after a period of time is that the pump will run and run and won't shut off at all. This is the easiest one of all to fix. Most of the time when a customer says to me"Brad, the damn thing just never shuts off" I ask is this an 80's or early 90's vessel? Almost always it is. The fix is to replace the vacuum switch. The vacuum switch in older models is located in the end of the large white accumulater tank. The accumulater tank is a large white round tank with 2 wires going to one end of it. The little nub that sticks out from one end is the vacuum switch. Simply remove the 2 wires(paying attention to wheather they are on the "A" side or"B" side). Unscrew the entire assembly from the end of the accumulater tank and screw a new assembly in. Clean the surface where the large o-ring rests and lubricate it with dish soap. Never use grease or vasoline or anything petroleum based as a lubricant. Reinstall your wires and you are back in action.

The accumulater tank is most often found in the bilge in the engine room. Somtimes below the floor forward. In older 37 and 39 searays it is under the pull out dinette seat, a real pain in the rear.

If your toilet is in the 2000's for age then you probably have a vacuum generater. There are 2 types of vacuum generaters. If your vacuum generater has a black vacuum pump then it is a VG-3. The vacuum switch is located under the flexible plastic cover on top held down by two small screws. Remove this cover and loosen the hose clamp holding the vacuum switch in place. Pull the vacuum switch out(not threaded) and disconnect the wires. Install the new switch is the reverse of what we just did. Use dish soap on the double o-rings and be sure that they do not roll out of there little slot when sreinstalling as this will create a small vacuum leak. Soap up the opening and the o-rings, insert the vacuum sitch, now slowly turn the switch in the hole and look to make sure the o-rings are in place. Tighten hose clamp and reinstall wires, you are done.

The second vacuum generater is only if you have an 2006 or newer model. This is a J-W series unit. It will have a white pump on top of it. The vacuum switch sticks up, under a cover, in one corner of the unit. Very easy to get to. Simply remove the switch and install a new. As always these parts are available at very reasonable cost at www.marinediscounters.com"

I have a 1987 390EC. I would like to find out where the vacuum switch is located, that shuts the pump off, before I start taking things apart. There seems to be plenty of vacuum at the head but the pump never stops. Any help would be appreciated.