Pump but no air

My Daro dual pump stooped pumping, the pump is on and runs but there are no bubles. I checked the rubbers but there still fine, the pump is almost new.

When I check by putting it through a single lose into the tank is's fine but when i put different air stones on it it does not work!

This should not be that difficult but I cant seem to figure it out?

 

take it back to the shop....

 

I bought it 1 year agow

 

Well let me say i dont really know about fish pumps but i have worked alot on large compresser units and if its anything like that , your problem is the seals have worn and when there is a heavy load on the system ( like adding multiple are stones) it will not pump anymore ( the pressure pushing back is to great) and the air is forced out between the seals and not out the tube. well i could be completely wrong but thats my 2cents worth:bigsmile:

 

Don't know that particular pump, but I think they all work in a similar fashion. You have a vibrating arm that expands and restricts a diaphragm, thus generating air pressure. Usually it is one of two things, if its something you can fix. Either the black diaphragm is perished and does not build up pressure or, on the outlet of the cylinder that the diaphragm fits onto there is a valve, a small see thou plastic in the shape of a figure 8, the one circle being a lot bigger then the other. If this valve is broken or not functioning properly the pump does not build up enough pressure. This valve is located under a semi circle black rubber, that keeps it in place. Both the diaphragm and valve is usually available as replacement parts. It can be tricky to disassemble the whole pump, if you are not comfortable with doing it rather don't. If you need more info pm me.

 

Yes Roger totally agree - One last thing you can check if the diaphragm is not perished or the valve broken, open the bottom and turn it on - check that the arm connected to the diapragm is moving at least about2-3mm back and forth. attached to the arm is a magnet that is attracted and then repelled to the E shaped inductor - if your mains windings are internally short you will not get the full displacement of the arm. The arm can be bent a little further out from the diaphragm if need be - but this will create more stress on the diaphragm..

When it is open and you have mains on it - WATCH OUT - The trminatgions on the inductor are LIVE and may KILL you, or give you a GOOD wakeup call. If you are not happy playing with MAINS - STAY AWAY..

Reafer what you are saying is exactly what we all agreed with - Man this Forum ROCKS