Priming washdown pump

Post here if you want to discuss a topic specific to the MV/32, MV/34, and MV/41.
Post Reply
User avatar
AMCarter3
admiral
admiral
Posts: 450
Joined: Thu Apr 21, 2016 8:32 am
Location: Bellingham, WA
Contact:

Priming washdown pump

Post by AMCarter3 »

Any suggestion for priming the washdown pump? After cleaning the filter on it last Fall, it has not been used. Now it doesn’t prime. The thru-hull is open and the pump runs.., I spurts of air out the deck fitting, but no water. I also tried filling the filter cup.
Mac Carter
2006 34' PDQ PowerCat "All Heart"; MV 98; twin 100 HP Yanmars
Home Port: Bellingham WA 98229
deising
admiral
admiral
Posts: 361
Joined: Mon Sep 15, 2014 3:48 pm
Location: Punta Gorda, FL
Contact:

Re: Priming washdown pump

Post by deising »

I don't know the internal design of the pump, so maybe this won't work. You could try inserting the hose, removing the spray nozzle and pouring water back down with a funnel. If the water dribbles into the pumping mechanism, that might make a prime.
Duane Ising
m/v Diva Di
Punta Gorda, FL
2006 PDQ MV 34 - hull 91, 75HP, 3-blade
User avatar
AMCarter3
admiral
admiral
Posts: 450
Joined: Thu Apr 21, 2016 8:32 am
Location: Bellingham, WA
Contact:

Re: Priming washdown pump

Post by AMCarter3 »

Duane, if you mean our water down the deck fitting, I tried that 3 times. It only accepts a little water and it did not prime the pump.

My next thought was to remove the hose clamps on thd intake hose sync put water down it.
Mac Carter
2006 34' PDQ PowerCat "All Heart"; MV 98; twin 100 HP Yanmars
Home Port: Bellingham WA 98229
deising
admiral
admiral
Posts: 361
Joined: Mon Sep 15, 2014 3:48 pm
Location: Punta Gorda, FL
Contact:

Re: Priming washdown pump

Post by deising »

I can't quite picture the arrangement right now, but moving the pump as low as possible would certainly help. That might not be very easy. Good luck.
Duane Ising
m/v Diva Di
Punta Gorda, FL
2006 PDQ MV 34 - hull 91, 75HP, 3-blade
duetto
admiral
admiral
Posts: 984
Joined: Wed Jun 15, 2005 11:18 am
Location: ICW (32043)

Re: Priming washdown pump

Post by duetto »

when you release the nozzle does the pump continue to run? if so, it could be an air leak downstream from the pump. the strainer seal ring would be a likely place but we had a pinhole develop in the hose to the strainer which had the same symptoms. if you have the same jabsco pump as we do it we easily self prime. another possibility is a faulty or clogged check valve in the pump head. if it's a clog you can disassemble the head and clean it. if the valve cups have taken a set you may have to replace.
john & diane cummings
duetto mv34 #23
User avatar
AMCarter3
admiral
admiral
Posts: 450
Joined: Thu Apr 21, 2016 8:32 am
Location: Bellingham, WA
Contact:

Re: Priming washdown pump

Post by AMCarter3 »

I solved it. The strainer cup was not completely tight. My maint. tech guy suggested that and, after tightening it, it instantly primed and we had water flow.

Thanks for the ideas! It all helps.
Mac Carter
2006 34' PDQ PowerCat "All Heart"; MV 98; twin 100 HP Yanmars
Home Port: Bellingham WA 98229
Tom Green
skipper
skipper
Posts: 72
Joined: Fri Jun 22, 2007 10:39 pm
Location: Sammamish, Washington

Re: Priming washdown pump

Post by Tom Green »

My washdown pump also lost its prime and would not function.

The 90 degree elbow fitting that screws into the deck valve was loose. The caulking that was used at installation was deteriorated. Took it off. Need to remove hose from pump to unscrew fromdeck fitting. Clean fitting well and applied some good tape and replaced it and reconnected hose. The pump it primed itself just fine. All is well.

He key seems to be finding the air leak in the system.
Tom & Nanci Green
Diastole
MV3499
Post Reply