[C320-list] Bleeding calorifier for cooling?

[jim brown]

Graeme,
Warren's advice is a tried and true method for bleeding air from the engine cooling system (both in older cars and boats). 

However, if you are asking if changing the impeller and introducing air into the fresh water cooling circuit can cause an air lock in the heater circuit I don't think that's possible. The fresh water circuit feeds water through the impeller pump, heat exchanger, and out through the muffler and exhaust and is entirely separate from the engine cooling system with the antifreeze. It is isolated from the engine block and head cooling system in the heat exchanger. So any air lock in the fresh water system would cause the engine to overheat and you'd get plenty of hot water and no exhaust burble.  It would be unlikely that you could have an air lock in the fresh water circuit by changing the impeller since it is a straight through circuit to the outside with no pressure. The pump plus 11,000 pounds of displacement would almost certainly push that water up and out. 

The valves and faucets on the water are to relieve pressure, drain the tank, prevent backflow, etc. You certainly can get an airlock in this house water system separate since sometimes (don't know why) the pump is not always "self priming". 

You normally don't drain the engine coolant for winterization but if it was drained to change it out when spring commissioning then see Warren's email. You will have an airlock in the circuit to the water heater unless you do. Been there.

If I'm not understanding your original question I apologize. 

Jim Brown
# 973  Yannar 3gm


      From: Warren Updike <wupdike at hotmail.com>
 To: "C320-List at Catalina320.com" <C320-List at Catalina320.com> 
 Sent: Saturday, March 18, 2017 4:46 PM
 Subject: Re: [C320-list] Bleeding calorifier for cooling?
   
"calorifier" huh? Oh, you mean the water heater. I had to look that one up. 

It's possible to get an air lock in the hoses to the calorifier. You can tell because you won't have hot water after running the engine. There are a couple of techniques people use to clear the airlock. What I have done that seemed to work is to 1) remove the filler cap on the heat exchanger and if very full remove a small amount of antifreeze, 2)remove the highest hose to the calorifier at the engine, insert a funnel into the hose, hold funnel and hose as high above the engine as possible, and pour in antifreeze slooowly. This may force any air out of the hose and into the engine. You may even notice the level in the heat exchanger rise. Hope this helps. If not, try another technique.

Warren and Pattie Updike
1994 C320 "Warr de Mar" #62
Middle River, Chesapeake Bay

-----Original Message-----
From: Graeme Clark [mailto:cg at skyflyer.co.uk] 
Sent: Saturday, March 18, 2017 10:09 AM
To: Catalina list
Subject: [C320-list] Bleeding calorifier for cooling?

This will be first year I am attempting to re-commission and de-winterise my engine
I have fitted a new pump impeller and refitted the fan belts but was wondering whether there will potentially be an airlock in the heating system, especially the  loop that goes to the calorifier
There are a lot of valves and faucets on the calorifier which I have never previously touched!
Do I need to bleed anything and if so, how?
Thanks
Graeme
#366, 1996


Sent from mobile: please excuse typos etc.!