Pressurizing Engine Coolant System

[svprovidence]

Would love to get in touch with other Gozzard 44 owners. I have been working on mine now for 4 years and sure could use some advice. Right now I am trying to break the airlock in the cooling system and nothings seems to work. Seems the airlock occurs in the hot water heater look coming off and returning to the heat exchanger. Any advice would be greatly appreciated

[svprovidence]

FYI the water heater is higher than the engine. Here is how it is set up and what I have tried . . . 1" hose comes off heat exchanger acting as the feeder line up to an expansion tank located in the cockpit. From there another hose comes off the expansion tank which is the return hose going to the hot water heater and then back down to the return side of the heat exchanger. It took me 5 times to flush the engine before I could get out all of the old coolant. I have no idea why the system would not drain all the way particularly since I had the radiator cap off the expansion tank and the manifold and removed the return side of the heater hose from the exchanger. When the filled the system with new coolant, I was only able to get it to take 3 of the 5 gallons. The procedure I used to fill the coolant was as follows: I used the expansion tank as the fill point since it was the highest point. I removed the hose from the heat exchanger on the return side and plugged it. I then began filling the coolant from the expansion tank until it came out the barbed side of the heat exchanger where I had removed the hose. I then plugged that side and unplugged the return hose until coolant ran freely from that point. Once I knew the coolant was running freely on both sides, I re-installed the hose. I then opened the petcock on the heat exchanger to purge it of air. Then I opened the pet cock on the thermostat housing to bleed it from that point. The level in the reservoir still does not go down. I tried using a Stant coolant pressure tester to pressurize the system from the radiator cap on the manifold but all that did was backflow. I then tried to pressurize the system from the reservoir using the same procedure and that did not work. Then I went out and bought a fluid transfer hand pump and placed a hose on the return side of the expansion tank and put the other end of the hose in the coolant container and began pumping. I was able to get a little more coolant in the system but I am still 2 gallons away from filling it. I am stumped. I have been at this for 4 days now and nothing seems to work. Please help.

[FlyingCloud1937]

Pull your temp sending unit, it should be just below the T-stat, this should allow the system to bleed the air.

The run it with the stant of the header tank until you see water moving, this means the t-stat is open, let it run for 1/2 hr, then let it sit over night with the stant off.

Lloyd

[svprovidence]

Thanks for the help! I will give it a try . . .

[svprovidence]

Question: By the header tank, am I correct in assuming you mean the expansion tank located above the hot water heater?

[FlyingCloud1937]

Originally Posted by svprovidence

Thanks for the help! I will give it a try . . .

Just to be clear, please re-install the temp sender before you run the engine. I failed to note that in my prior post.

Lloyd

[FlyingCloud1937]

Originally Posted by svprovidence

Question: By the header tank, am I correct in assuming you mean the expansion tank located above the hot water heater?

Yes, if this is where the stant/radiator cap is.

Lloyd

[svprovidence]

Also, I have been trying to get the engine up to operating temp at 180 degrees but it never reaches it. is that because the system is not pressurized?

[svprovidence]

There are 2 radiator caps - one on the manifold on the engine and one on the expansion tank. The stant works best on the engine but gets hung up on the expansion tank.

[FlyingCloud1937]

Originally Posted by svprovidence

There are 2 radiator caps - one on the manifold on the engine and one on the expansion tank. The stant works best on the engine but gets hung up on the expansion tank.

OK,

We now need a time out.

I' am sitting down to dinner, and maybe a movie with my wife. I have some thoughts, but will need some more info.

2 caps, means the one lower is not a pressure cap, and the higher is.

So don't take anything I've said as advise yet. STOP.

I will endeavor to help as fast as I can.

Lloyd