Burping air out of coolant system

I recently changed my water heater, in doing so I introduced air into the freshwater coolant system of my Lehman 120 hp, 2715E engine. I picked up one of those coolant fill kits but all the adapters to the radiator are for automotive. Have any of you found a radiator fill adapter for a coolant kit? Do they stock them on Amazon, I’m having a hard time finding one hear in Vancouver, BC

I’ve been phoning around and the radiator guys just say run it with the cap off and the air should escape no problem. Does this make sense?

That is what I did to the Lehmans in our last boat when I changed the coolant. Same with my Cummins in the current boat l

I had an old mechanic tell me to just drill a small (1/8") hole in the thermostat to bleed the air. The beware Yanmar Tstat i ordered came predrilled. No problem bleeding / filling

Ive also ran n my Lehman with the cap off to purge air. Ive done that on older cars also.

grahamdouglass said:

I recently changed my water heater, in doing so I introduced air into the freshwater coolant system of my Lehman 120 hp, 2715E engine. I picked up one of those coolant fill kits but all the adapters to the radiator are for automotive. Have any of you found a radiator fill adapter for a coolant kit? Do they stock them on Amazon, I’m having a hard time finding one hear in Vancouver, BC

I’ve been phoning around and the radiator guys just say run it with the cap off and the air should escape no problem. Does this make sense?

Click to expand...

From Lehman manual:
"DO NOT OPEN VALVE WHILE ENGINE IS RUNNING, as this will draw air
into system, displacing water and causing overheating of engine.

Most complaints of overheating are due to improper purging of airfrom the fresh water system. The following is correct
method with engine not running:
A. Open air bleed valve (on top front end of manifold)
to allow air to escape.
B. Remove filler cap from top of expansion tank.
C. Slowly fill cooling system with water/anti-freeze mixture
D. Continue filling cooling system until all air or bubbles cease to expel at air bleed valve, and solid stream of water appears.
E. Close air bleed valve.
F. Continue filling of cooling system until water level reaches top of expansion tank.
G. Start engine and run approximately 900 RPM (in neutral) until thermostat opens. Turbulence in water will be noted through filler hole.
H. Maintain water level to top of tank.
I. Replace filler cap.
DO NOT OPEN AIR BLEED VALVE WHILE ENGINE IS
RUNNING, AS THIS WILL DRAW AIR INTO SYSTEM AND
DISPLACE WATER AND CAUSE OVERHEATING.

I tapped into the rad head to redirect water to a hot water tank.
Works well.
We notice a approximately 10 degrees difference in engine water temp.
Most diff open the manifold bleed valve, while filling the tank, and close once manifold is full.

Curious if you use heavy duty green line belts for the pump/alternator?
and
How often do you replace belts?
Our belt set up requires we "hang" spare belts as back ups, as the return hose goes thru the center of the belt! One day Im going to redirect this belt so as I can replace belts easier.

Mark
Cathryn Grace,
Saltspring Island

Rollysflyinghigh said:

I tapped into the rad head to redirect water to a hot water tank.
Works well.
We notice a approximately 10 degrees difference in engine water temp.
Most diff open the manifold bleed valve, while filling the tank, and close once manifold is full.

Curious if you use heavy duty green line belts for the pump/alternator?
and
How often do you replace belts?
Our belt set up requires we "hang" spare belts as back ups, as the return hose goes thru the center of the belt! One day Im going to redirect this belt so as I can replace belts easier.

Mark
Cathryn Grace,
Saltspring Island

Click to expand...

One concern if you break a belt and don’t have a spare in place be extremely careful about removing the hose with the engine hot. I read an article about someone pulling the hose and got burned so badly he had to be taken to the hospital and took a long time healing. So have a spare belt in place so you don’t get burned trying to change the belt.

Comodave said:

One concern if you break a belt and don’t have a spare in place be extremely careful about removing the hose with the engine hot. I read an article about someone pulling the hose and got burned so badly he had to be taken to the hospital and took a long time healing. So have a spare belt in place so you don’t get burned trying to change the belt.

Click to expand...

Oh Brother, its a goat fuc.
We keep three belts "hung" alongside ready to replace.
Fun fact.
Its a sh!t design, the moment a belt breaks, we notice the spike in water temp gauge, we shut er down.
BUT, by that point the head has already blasted water out the head!!!

Honestly Im so new to this world, I havent figured out if it is the belt breaking first OR did the head blow causing hot water to destroy the belt?!?!?!
Ive set up CCTV to observe the engine run under way.
AND, like I Said before Im going to redirect the hose so that the belt doesnt run around the hose.

Thanx for your input.
M

GB32Seattle said:

From Lehman manual:
"DO NOT OPEN VALVE WHILE ENGINE IS RUNNING, as this will draw air
into system, displacing water and causing overheating of engine.

Most complaints of overheating are due to improper purging of airfrom the fresh water system. The following is correct method with engine not running:

DO NOT OPEN AIR BLEED VALVE WHILE ENGINE IS
RUNNING, AS THIS WILL DRAW AIR INTO SYSTEM AND
DISPLACE WATER AND CAUSE OVERHEATING.

Click to expand...

Yeah, yeah, yeah. When I was in my 20's I was the smartest guy in the world and knew everything, certainly more than any old, yellowed manual.

Oops, come to think about it, I did exactly what @GB32Seattle says not to do. Sh*t, maybe I wasn't so smart after all

Is the water heater's heat exchanger and all of the plumbing between the engine and WH, below the pressure cap? If not, this can create an air lock. If all of this is not below the pressure cap, the correct approach involves installing a remote expansion tank. If it's borderline, you can sometimes get away with it, which might be your case.
More here Water Heater Primer | Steve D'Antonio Marine Consulting

I'm a fan of the Gates green Fleetrunner belts. If you replace belts routinely, and tension properly, they should never break. I advise my clients to replace belts preemptively, about every three years or 600 hrs., WECF. You can go longer with FleetRunners, but for ordinary 'black' belts, it's just not worth the risk for the cost. More on belts here Editorial: Reviewing Invoices – Feature Article: Fan Belts | Steve D'Antonio Marine Consulting I also recommend replacement of impellers annually, regardless of hours. More on that here Raw Water Pump Service – Editorial: It’s Just Lunch | Steve D'Antonio Marine Consulting Part of the value of this is, it keeps hardware "exercised" so it doesn't seize, while you are doing this, and you get to closely inspect these components and those around them, and you almost always notice something that needs to be serviced. More on that subject here The Boat Genie in the Cigar Box | Steve D'Antonio Marine Consulting

Steve,

I just spoke with a engineer at Gates Friday about a green belt for my 6.7 Cummins QSB. He could not find a reference. Do you have a suggestion?
Thanks,
Rob

If you have access to an air compressor I’d suggest to use an air lift to fill your coolant system for troublesome engines. Plus a small hole in the t stat helps.

This is what you need. From American Diesel.

Datenight said:

Steve,

I just spoke with a engineer at Gates Friday about a green belt for my 6.7 Cummins QSB. He could not find a reference. Do you have a suggestion?
Thanks,
Rob

Click to expand...

There is an online cross reference, I'd try that just to confirm, if unsuccessful, you can go my the dimensions and ribs on the belt to find the right one.