DP-C drive, replace molded rubber hose

dell30rb

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Joined
May 7, 2015
Messages
3
I have a volvo DP-C drive with a 5.7 indmar motor. I recently installed a clear perko flush kit and noticed I am getting some air sucked in with the water. The engine runs right at 140F, but one of the manifolds/risers is running about 150-170F - the other is nice and cool, 120-130F. The raw water pump impeller, thermostat, hoses, manifolds and risers are all less than 1.5 years old. This is a saltwater, raw water cooled boat.

Video of water getting sucked in. This is about 1200rpm
https://www.youtube.com/watch?v=ni6HbxUjHRw


While my boat seems to be running fine I don't like the air getting in, and I am going to replace the only hose that has not been replaced - the rubber molded intake hose and the associated o-rings and gaskets through the transom shield. I pulled the hose clamp on the drive end of this hose and disconnected it today, the nipple that bolts to the drive is in good shape, no pitting, cracks or corrosion. This is a common failure point I know, and it also happens to be below the waterline when I see air bubbles coming through the intake, so I know its not the problem.

My question is - do I remove this hose by unbolting the fitting on the inside of the transom, and the hose simply slides through the transom shield into the boat? I haven't seen anything in the manual or online about how to remove/install this through the transom part.

I ordered a new hose, and the oring #18 and nipple fitting #10 and it should be here in a few days.

11199_4.png
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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47,297
Replace the inlet casting (item 19)
 

dell30rb

Recruit
Joined
May 7, 2015
Messages
3
I checked that part and it was fine, per the OP.

The problem turned out to be that the plastic fitting #11 was cracked and sucking air. It was actually leaking a bit of water when the engine was off.
 
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