1989 Volvo Penta AQ271c cooling system

[jhetrick55]

Hey, I'm looking for some advice on part of the cooling system on this engine. Where the raw water hose comes through the transom, it goes into a plastic fitting which turns into a black tube with a couple rubber hoses coming off of it and at the top it goes into the raw water hose which runs to the impeller. Sorry I don't have pictures.

Does anyone know what this black, vertical tube does? Is it possible that this tube could be plugged? I can't seem to find anything to help me identify this. Thanks!

 

[jhetrick55]

I think I figured it out... I believe its the steering oil cooler.

 

[QBhoy]

I think I figured it out... I believe its the steering oil cooler.

It sure is. Quite prone to getting perished or corroded abs drawing air, not allowing the impeller to pull water well.

 

[Scott Danforth]

Power steering cooler, and it's copper

 

[Scott Danforth]

If you are having cooling issues, check the fitting on the drive

 

[jhetrick55]

Scott, I have replaced that fitting with a brand new one. The old one crumbled when I removed it.
As for the power steering cooler, if I flush water out backwards, it doesn't seem to have any issues - comes on good and strong. QBhoy... you're suggesting it may have trouble due to corrosion internally? What is their lifespan generally?

 

[Scott Danforth]

if you are concerned about the power steering cooler, pull it out and have it pressure tested.

they are a simple pile of plumbing tubing and parts.

 

[jhetrick55]

Good idea, Scott. Thanks!

 

[QBhoy]

Scott, I have replaced that fitting with a brand new one. The old one crumbled when I removed it.
As for the power steering cooler, if I flush water out backwards, it doesn't seem to have any issues - comes on good and strong. QBhoy... you're suggesting it may have trouble due to corrosion internally? What is their lifespan generally?

Yeah. They can suffer and end up causing a loss of prime to the pump.

 

[kenny nunez]

Another place to check is the seal where the lower gear housing contacts the water tube on the suspension fork. When the boat planes off air enters the incoming water flow.
Sierra #18-3888 lower seal kit.
Raise the drive and drain the oil and with some Allen wrenches the lower drops off. This is an easy job.