Bilge Pump Problem

[Ironhorse74]

Just got done with a 5 day cruise. I had recently installed a Jabsco 36600 diaphragm bilge pump. Less than 90 days old. Tested it, used it etc. Two days out of Bellingham I was in fairly rough seas in the straight of Juan De Fuca. Heard water sloshing in the bilge. Went down and checked the bilge pump and it was blowing air into the bilge not pumping water out. So I disassembled the pump cleaned the check valves and reassembled it. Not much in the check valves. Nothing I thought could have been a problem. After I re installed the pump, it did the same thing. So I reversed the hoses. Started to draw water and then went into hydrostatic lock. Well duh the check valves would not allow water to flow in that direction. Then it dawned on me. The electric motor was turning the wrong direction. So I put the hoses back on correctly checked that positive was still positive. It was. Sure enough still blowing air into the bilge. So I reversed the electrical connection. Motor still turned the same direction.

Broke out the whale gusher and bailed the boat that way. I am however stumped at the problem. Any suggestions?

Brad

[daddle]

If the motor is indeed turning in the wrong direction, and I'm not so sure direction matters on a diaphram pump, and the direction doesn't change with a polarity change, then it is a series wound motor. To reverse such a motor one needs to open it up and swap the stator to armature wires.

Pumping air indicates a goofed up valve.

[Ironhorse74]

Daddle, now that I think about it, you are right about motor direction. Just can't figure out why it would be the valves. Took them out and cleaned them, still did the same thing afterwards.

[daddle]

Can the valves be installed backwards? Of course one should be in and the other out.

[Ironhorse74]

Yes the valves could be installed backwards. This however does not explain why it suddenly stopped pumping and started blowing.

[Ironhorse74]

Contacted Jabsco. They do not have a clue why this pump is blowing as opposed to sucking. They are sending me out a new one, no charge. I can't complain about their customer service. Still makes me wonder why this happened. Not sure I can ever trust it again. I think I will add a submersible pump. That will bring me to three bilge pumps.

[HopCar]

Very strange! You did say that the pump worked correctly when first installed and that you didn't take the pump apart until after it failed?

These pumps are stupid simple. It sure sounds like a valve problem. When you open the pump and can see the valves, you should see the metal side of one valve and the rubber side of the other. The "rubber side up" valve is the intake valve and the "metal side up" valve is the discharge side. I often see these pumps with the valves installed wrong. The rivit that holds the rubber in the metal valve frame often fails during use, but you would have seen that when you removed the valves to clean them.

Another common problem with these pumps is a cracked plastic housing. The plastic is very brittle and can be broken by an impact or more commonly by an over tightened screw. Though I don't see how a cracked housing would cause your problem.

Jabsco is great at handling warranty problems.

[Ironhorse74]

Hop Car, yes it did work and work well until it decided blow air. I had not taken it apart until it gave me problems. Valves looked great other than some small debris in them. I reassembled the same way they came out.

Sounds like a mystery to Jabsco too.

Brad

[HopCar]

Well at least you can use it to blow up your inflatable toys!

[justlearnin]

Well if 1 of those pumps doesn't activate an alarm your prob looking for trouble

[Ironhorse74]

Originally Posted by HopCar

Well at least you can use it to blow up your inflatable toys!

LOL Yes! You sound like you really know pumps. I have a 60 gallon bilge fuel tank and a 25 gallon day tank. What kind of pump would you recommend to transfer fuel from the bilge tank to the day tank?

TIA

Brad

[Kapena]

The exhaust valve isn't sealing or the diaphragm has a small tear in it. JMO

[HopCar]

Hi Brad, If we're talking diesel fuel, I really like the little Italian gear pumps that Reverso sells: Reverso Diesel Transfer Pumps
The vane type pumps that Jabsco and Groco make would work well in that application also: GROCO Vane Pump SPO-60-N 12V
You can use rubber impeller pumps with the right impeller but they will be trouble in the long run.
If you decide to buy one, please give me a chance to quote you.

If it's gasoline, you need something with an explosion proof motor. It takes a pretty specialized pump to safely move gasoline. I think Northern Tools shows some in their catalog.