[C320-list] Heat Exchanger Removal - Perkins M30

[Dave Hupe]

 Hi Jeff-
I had an article published in Mainsail last Fall for replacing the entire heat exchanger tank on the Perkins Perama M30, which also involved removing the heat exchanger tube, having it cleaned, and replacing the front and rear rubber cups. It sounds like you won't be doing such an involved job.  Just removing the exchanger tube is much easier.  If you want the entire article, either look it up or I can email the text and photos to you.  
To remove the tube, I suggest at least partly drain your engine antifreeze first, otherwise you will have a lot of antifeeze leak (or this would be a good time to replace it entirely).  My article talks about this.  Then you will need to take off both the rear and front rubber cup assemblies. The exchanger tube will slide straight out the front of the heat exchanger tank when the rubber cups are removed. As Christian suggested, I also would recommend getting new rubber caps and stainless steel clamps for both front and rear, especially if they have never been replaced.   Here is a great place in United Kingdom for parts that I've used several times (including last buying a new heat exchanger tank and the end caps, etc.) https://www.parts4engines.com/perkins-perama-m30-parts/  Their shipping turnaround and speed/rates are very good. Also, replacing the hose coming from the seawater pump,  through the anti-siphon valve and into the front of the heat exchanger tube at this time would be a good idea (again if old). 
Note .... When I pulled my front rubber cup off the heat exchange tube, I found about 2 dozen pieces of old impeller sitting in the front rubber cup (inlet end of the exchanger tube)...... Yikes!! Apparently old pieces were not retrieved when missing by previous owners. Remarkably, the small tubes of the exchanger tube inlet side were not plugged by these chunks, but the chunks probably flowed in front of the tube inlets when the engine was running.  I didn't overheat because of this, but just make SURE the hose from the seawater pump doesn't contain old impeller chunks.  
Pay attention to the orientation of holes on the side of the exchanger tube when you remove it for re-installation.  On mine there were 2 side holes pointing straight downward into the heat exchanger tank. I had my tube tested and cleaned (ultrasonic) at a local radiator shop, but you may be able to accomplish it yourself. I actually was surprised how clean the small internal tubes were (probably since my boat is freshwater). Also, my exhaust elbow was remarkably clean (again likely due to freshwater).  Removing the exhaust elbow is not needed to remove the heat exchanger tube.  In fact, that is a whole other issue (as detailed in my Mainsheet article) to remove from the engine block and the short exhaust hose heading into the wet muffler.  
Putting the exchanger tube back in likely will require 2 people (so the it can be slid in from the front and seated firmly into the rear rubber cup).   The tube should stick out of the heat exchanger tank equally in the front and back. It will take a person in the rear pushing forward on the rear rubber cup while another person slides the tube rearward and seats the tube properly into the rear cup. Don't clamp anything until you are sure you have the tube seated firmly in the front and rear cups and the cups are properly seated on the heat exchanger tank. 
Feel free to get back to me if you want additional info or any photos. 
Dave Hupe1994 C320 (#32) "Mayan Sun"Holland, MI