Burping
- Thread starter Matpearce
- Start date
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 23,211
Mat.
Guessing that you are talking about the closed loop system using the antifreeze/ water mixture.
Options include:
Guessing that you are talking about the closed loop system using the antifreeze/ water mixture.
Options include:
- Open tank to fill, open the highest fitting in the system. This is usually a hose on the hot water tank. Fill system till water/antifreeze flows out. Close fitting, start engine, top of tank. Monitor temps.
- Or you can try filling tank, rocking boat. Filling tank, rocking boat. Start engine. Fill tank. Monitor temps.
- I've heard of owners attaching a small pump to there system to pump antifreeze/water mixture into their system till it filled the system.
On my 2qm15 fresh water loop I had to loosen the thermostat fasteners to get a bubble out the other day. I knew there was a problem shortly after I started the engine for the first time this season after replacing the antifreeze. My hearing is not what it used to be so several years ago I installed a boat horn under the helm seat that is connected to the idiot light overtemp sensor. I forgot that this horn was there until it went off with sufficient volume to wake the dead. Scared the hell out of me but probably saved the engine.
There are some good threads Stu has collected on the C34 forum. Some involve rearranging the plumbing to help with burping the hot water tank. Other disconnect specific hoses till the air is vented
Les
Les
There is a thumb screw on top of the thermostat housing that is for burping air from the system. There is also another thumb screw on a PVC T installed in the line at the water heater. With the engine running you open these up one at a time and keep them open until you have coolant flowing out and not air. But these thumb screws get hot and you might burn yourself so be careful.
Here is the discussion on the C34 board about the subject. Most things on the C34 board are applicable to our boats as well.
Personally I went with the system described in reply #14 on the link above by Mainesail.
Here is the discussion on the C34 board about the subject. Most things on the C34 board are applicable to our boats as well.
Personally I went with the system described in reply #14 on the link above by Mainesail.
This is the easiest way to bleed the system:
I designed this a number of years ago and have installed one on every engine since. The M-25 has a spot for a real ball valve on top of the t-stat housing.
1- Fill the engine as much as you can with antifreeze via the manifold.
2- Do yourself a favor and lose the sub par, burn your fingers, twist and open "pet cock" and replace it with a real ball valve. This one is male X female to reduce the number of fittings. Then connect a hose barb and a three to four foot piece of clear PVC hose. This hose now becomes your engines new "high spot" for both venting and purging air AND topping up with antifreeze..
3- Open the pet cock/ball valve and fire up the engine with the hose held high above it and let her run.
4- As the engine warms and the t-stat opens fluid may rise in the hose. As it drops, when the stat opens, use a transmission fluid funnel connected to the hose to fill it with antifreeze. Eventually the fluid will never dip back into the t-stat cap as the t-stat opens and closes. At that point the system is full and all the air has been purged.
5- Close the valve.
6- To drain any remaining antifreeze in the hose simply dip the hose end into an empty soda bottle to capture what is stuck in the hose after you closed the valve and you're good to go. Air and antifreeze DON'T mix well, especially if you are using Death Cool (AKA DexCool)...
