Volvo Md3b Cooling Problem.

[touchwoodtoo]

During last season I experienced a problem that I havent had before. Following sailing through moderate seas, when I started the engine, the cooling water was regularly airlocked. To solve the immediate problem I simply had to bleed the system as far as the inlet to the Jabsco pump. There are no obstructions in the strainer and the impeller is new.

 

[VicS]

Look for sources of air ingress if you have any parts of the intake system (eg strainer) above the water line and the possibility that the insides of one of the inlet hoses is collapsing. It could be due to wear in the water pump itself, either in the back of the impeller cavity or of the end cover plate resulting in poor sealing with the sides of the vanes leading to difficulty clearing any air which is drawn. You are sure that the inlet seacock/gate valve is fully open?

 

[Dave_Noakes]

Check all the components carefully for any cracks or similar that may be opening up and allowing air in . Moderate seas might be enough to cause movement if there is anything just a bit loose.

Dave

 

[LadyStardust]

Have a look at my post on a very similar matter, My problems started after I changed the impellor and fitted a speedseal, I am convinced I must be getting air in at the water pump now. My Post
Good luck