aq130 C. Impeller pumps, but will not self prime.

[madstories]

I just replaced my impeller. I do not know how well the cooling system was working before hand. In any case now I can get the pump to pump water only f I disconnect the hose from where it goes through on the transom and stick a bucket of water next to the engine and put the hose in that bucket. When I do this, it pumps water nicely. I have also tried bypassing the outdrive by connecting a hose to the rubber hose on the outside of the transom, and putting that into a bucket of water. I cannot get the pump to work in this case. So I thought maybe it's the gasket on the transom, so I tried running a direct line over the transom into the bucket of water directly to my water pump, and still nothing. Again the only way I can get this thing pumping water as if I put a bucket of water right beside it and put the hose directly into it. I'm thinking maybe by now I screwed up my impeller by running it dry too much. I have been very mindful of this, and have tried not to run it more than 20 or 30 seconds at a time. And I have used Lube on the initial installation. The impeller still looks good.
I do not understand why there is no check valve. It would have to prime itself each time it starts, which seems troublesome.
I do not even know what to try now, I am completely baffled.

 

[madstories]

Here is a pic of the pump with the cover off. I am aware that if the cam is worn too low it won't pump well. I do not know what it should look like, or the service limit.
This impeller has 10 blades as opposed to 5. The guy at the marine parts store assured me that this would be okay. I tried even putting my old impeller in, but still no luck.

 

[dypcdiver]

Alloy elbow at the transom can corrode and cause this problem.

 

[Scott Danforth]

Water inlet casting needs to be inspected every 2 years when you replace the bellows. It is a common failure point.

Replace as required

 

[madstories]

Thanks for the response, I have already bought a new elbow, and an o ring for the transom connection. To test the pump I have a direct line, connected to the pump inlet in the boat, and run directly to a bucket of water beside the boat. It will not pump in this case. So Ive bypassed the transom and the o/d. The only way I get it to pump is if I put a bucket of water beside the pump, and put a 4' hose from direct from pump to bucket, then it will self prime and pump the water.
It seems like it is not enough sucking power to draw the water all the way from the ground.
I have the pumps outlet open so I can see if water comes out. Engine Cooling is still happening because I have attached a garden hose to the engine to run water through it while I test the pump.
After thinking about it for the night with a much calmer mind, I've come to conclude that it must be a faulty pump as the impeller is new, and I've eliminated all other problems.
Is it best to try and rebuild it with a new cam? Or should I buy a new one? Any ideas?

 

[GA_Boater]

If the pump cover is still off, tap the motor over a few times to see if the impeller is spinning.

 

[Maclin]

The pump is not designed to pull that far, meant to only need to draw water from the almost full hose from the transom, when drive is fully submerged.. Have you tried muffs, be sure to plug the hole on the bottom of the drive, use lots of water supply pressure.

 

[Scott Danforth]

Your not trying to suck up water with outdrive in a bucket, are you?
If so, it wont work. The pump is not self'priming.

Back the boat into the water

 

[dennis461]

I m going to use capital (uppercase) characters to separate my text, I'm not yelling (unless you engine is running )

....... I do not know how well the cooling system was working before hand. In any case now I can get the pump to pump water only f I disconnect the hose from where it goes through on the transom and stick a bucket of water next to the engine and put the hose in that bucket. When I do this, it pumps water nicely. I have also tried bypassing the outdrive by connecting a hose to the rubber hose on the outside of the transom, and putting that into a bucket of water.

FOR THIS PART, IS THE BOAT ON A TRAILER AND THE BUCKET ON THE GROUND?
HOLD THE BUCKET UP WHERE YOUR BOAT WATERLINE WOULD BE
I cannot get the pump to work in this case. So I thought maybe it's the gasket on the transom, so I tried running a direct line over the transom into the bucket of water directly to my water pump, and still nothing.

BY GOING UP OVER THE TRANSOM, YOU CREATED A LARGE AIR LOOP WHICH WILL SURELY PREVENT THE PUMP FROM SELF PRIMING

Again the only way I can get this thing pumping water as if I put a bucket of water right beside it and put the hose directly into it. I'm thinking maybe by now I screwed up my impeller by running it dry too much. I have been very mindful of this, and have tried not to run it more than 20 or 30 seconds at a time. And I have used Lube on the initial installation. The impeller still looks good.
I do not understand why there is no check valve.
I THINK A CHECK VALVE IS A BAD IDEA.WHEN YOU SHUT YOUR ENGINE OFF IN THE WATER, THE EXHAUST MANIFOLD HAS TO DRAIN IN TWO DIRECTIONS

It would have to prime itself each time it starts, which seems troublesome.
I ALWAYS PRIME SO MY IMPELLER LASTS LONGER/

I do not even know what to try now, I am completely baffled.

YOU COULD TRY MY METHOD USED WHEN I NEED TO RUN FOR MORE THAN A FEW MINUTES
https://www.youtube.com/watch?v=B2gcD78z64I

 

[dypcdiver]

It is might just be the input shaft seal that is allowing air into the system.

 

[iracer99]

I had a similar problem with mine. It would not pump when below 1000 RPM. (I put a piece of 12" clear vinyl tubing right before the pump so I could see it.) I too tried a new impeller, same prob. Neck and hose was fine.

I removed the pump cam which looked fine, but felt a little rough. I installed a new cam, problem solved. Cam was only 20 bucks.

Hope you get your issue figured out.

Tommy

 

[kenny nunez]

On the hose that supplies water to the pump, connect a garden hose to it and let water flow back through the outdrive, while that is happening try to stop the water from running out of the water intake. You should not see water leaking out of the area where the drive pivots and where the hose connects to the transom. This test will prove out any air leaks on the suction side through the transom.

 

[am_dew]

I ALWAYS PRIME SO MY IMPELLER LASTS LONGER/

https://www.youtube.com/watch?v=B2gcD78z64I

Just curious....how do you prime?

Thanks!

 

[madstories]

You dont actually prime it. U just hace to be sure there are no air leaks in the system. The impeller should just be able to pull the small amount of air in the line through and suck up the water. Thats how I understand it anyway. I have a manual for the aq130c and there is no mention of priming anything when installing the pump.

 

[dennis461]

Just curious....how do you prime?

Thanks!

I take the lid off of the strainer, pour about half a quart of water in, then close the lid.
Some of the water runs toward the heat exchanger, and some runs down to the pump on my AQ131 (125).
This way the impeller is starting up wet, not dry.
Now knock on wood, I've never had an impeller fail on me.

 

[am_dew]

I take the lid off of the strainer, pour about half a quart of water in, then close the lid.
Some of the water runs toward the heat exchanger, and some runs down to the pump on my AQ131 (125).
This way the impeller is starting up wet, not dry.
Now knock on wood, I've never had an impeller fail on me.

OK. I don't have a strainer on my engine.

 

[Lou C]

I've done this on my OMC Cobra to make sure it primes, I think it would work on a Volvo as well:
​Put the muffs on the drive and hook your water hose up to the spigot but don't turn it on yet.
​Go up to the engine and disconnect the hose that comes from the transom to the impeller housing. Fill that hose with water till you hear it leaking out around the muffs on the outdrive. Then re-connect that hose and turn on the water. Filling that hose and the water intakes in the outdrive should make it prime faster and easier.