kohler 7.3 impeller change

[mjk1040]

CaptBob; Your assumption of an air pocket in the antifreeze size will definitely give you an overheat issue. Even though you bleed the system through the bleeder plug, I think you have to be sure the unit was at thermostat temp. so it was open and you are bleeding the entire system and not just the bypass side of the system. Hope you remember the trick! Mike

[Viper]

I agree with Mike. Run her under load.

How have you confirmed she is shutting down due to temperature? How long will she run before shutting down?

[CaptBob]

The trick may just be plain persistence.

Yup, ran it under load, had it shut down after about 6-8 minutes (under load, both AC units on) Manifold temp was hotter to touch than heat exchanger. Checked AF, low at the cap side. removed the bleeder plug, filled the cap, squeezed the far hose (opposite the service (oil filter) side) and burped out some air. Burped some more with the hose and slammed the plug home while mid squeeze. (the hose on the service side has a coil spring in it, and cannot squeeze it.... but the other, squeeze away) released the hose, made sure the overflow hose was deep in the over flow tank, Hosed off the mess and fired it up. Ran at the dock for about 20 minutes under load, no shutoff. Went for a cruise, and hour or so up the river, up on plane for a bit of it (filled up the fuel tanks yesterday! )cruised back, anchored, ran continuously for about 4 hours.

I think it's fixed!

[bud37]

Heres a couple pics of the pump, interesting is how they are sealing the back of the pump to the rotation with the spring loaded seal.

[mjk1040]

Yep damn air locked again. Close the system and give us more head aches! Had the same problem with vehicles. Mike