Volvo Penta 2030D raw water pump problem

[yotter]

Help!
My VP 2030D raw water pump started to leak from the weep hole a few weeks ago, so I decided to sort the problem before the winter layup. I know this is not unusual for an engine at 10 years old and just over 1000 hours. I removed the pump, stripped it down and replaced both the water and oil seals (the bearings seemed to be fine). The pump shaft seemed fine, and the marina marine engineer looked at and confirmed that is was fine and just needed a clean with a fine abrasive, this was done with 1000 grit wet and dry. I am fairly confident that the pump has been reassembled correctly (but it is my first go at it). The problem now that it is reinstalled is that that no water comes out of the exhaust when the engine is run. I appreciate that there very many reasons for this, so I shall state what I have tried: Inlet seacock is open and tested as clear by blowing down the pipe. Pump output circuit is not the issue, since I removed the output hose from pump, and no water comes out. Impeller is rotating, pump cover removed and engine started to visually confirm this. There is a Vetus water filter between the seacock and the [pump input, so to eliminate this the pipe now comes direct from the seacock to the pump input. I suspected air ingress, so I removed both input and output hoses from the pump, put finger over input and blew down output, seemed to have positive pressure, so don't think this is the problem.

Any thoughts, you budding marine engineers?

Hoping to go for a last sail on Saturday (if I get this sorted)

Angus

 

[RichardS]

Have you actually primed the pump by pouring water down the outside of the filter/ inlet hose of the pump? These pump often don't pump properly until the impeller is actually pumping water rather than air.

Richard

 

[Tranona]

Reconnect the Vetus filter, close the seacock and fill the filter bowl with water, put the top on, open the seacock and then start the engine. You will have primed the pump so it should start pumping.

 

[yotter]

Richard and Tranona,
Many thanks for the rapid posts.
good to hear that these pumps are not great at priming. I did try filling the Vetus filter bowl, some of the water drains through the input seacock (saildrive), so I shut the seacock, filled the bowl, started engine then opened seacock. Did not work:-( . I will be back at the boat after work tomorrow, and will try these suggestions.
many thanks
Anguus

 

[RichardS]

Richard and Tranona,
Many thanks for the rapid posts.
good to hear that these pumps are not great at priming. I did try filling the Vetus filter bowl, some of the water drains through the input seacock (saildrive), so I shut the seacock, filled the bowl, started engine then opened seacock. Did not work:-( . I will be back at the boat after work tomorrow, and will try these suggestions.
many thanks
Anguus

Once you've filled the bowl to the brim you do have to screw the lid back on of course. And make sure that there is plenty of silicone grease (or vaseline if nothing else available) on the threads of the lid and on the rubber seal. If there is the slightest air leak the pump will fail to err......... pump.

Richard

 

[Bav34]

If the impeller is turning are you sure that sod's law hasn't kicked in and the rubber has came unstuck from the metal insert? It might look as though it's working with the plate off but spins under pressure.

 

[yotter]

Richard,
Many thanks for that, that did cross my find, and that's why I tool it out of the circuit to aid fault diagnosis. Currently the pipe comes directly from the seacock to the pump input (which is probably just below the waterline). I find myself doubting if I have correctly assemble the pump, but its pretty basic. I may try a pipe to a bucket of water tomorrow.
Angus

 

[Bav34]

Ahhh ... didnt see that ... post just about to be amended

 

[yotter]

Mystery solved But numty award to self:-(

Many thanks for the suggestions. I also spoke to a VP dealer who said that these pumps can be difficult to prime. I thought that, to help diagnose the fault, I would take the pump input hose direct into an elevated bucket of water, having first filled the hose with water. I then started the engine and to my amazement, bubbles appeared at the end of the hose in the bucket. I then discovered that it is very easy to refit these pumps out by 180 degrees! I unbolted the pump and refitted correctly. What a numpty, I should have taken or photo, or perhaps looked at a picture in the manual (although this pump is not well covered in the manual).

Very many thanks for your help

We can now go sailing tomorrow to the isle of Bute

Angus

 

[RichardS]

So you were blowing rather than sucking.

Glad it's solved.

Richard