912A coolant air bleed?

[Iceflyer]

Hi.

I need to replace a coolant hose due to serious chaffing with the frame. Just purchased the plane and have no manuals.

Do I need to bleed the coolant system for air after replacing the hose or do I just refill with coolant and go?

Its a Kitfox III with 912A

[SkyPirate]

2 choices ..drain the coolant completely and replace your hose,..refill..with cap not tight, run the engine to temp so thermostat opens ..shut down and refill,..or

Get bucket and funnel ready first ..disconnect lowest point of hose to replace ..drain until water stops..replace hose,..refill .. warm up until thermo stat opens ..refill ..should be good to go .

if you get air in the system you will see water temp fluctuate drastically,.. when the thermostat opens it will "burp" any air in the system leaving space to put more fluid in .

Chase

[SkyPirate]

also ,..take note to where the hose was rubbing ..even if you put stainless braided lines on I would put a shield on the area that was rubbing .. something ductile that can be formed like a 1/2 shell around the hose ,..wire tie it in place,..
I would not wire tie the hose in a way that pulled the hose away from the area that was rubbing ,..reason for this,..if you pull the hose away to far your putting more bends in the hose ,..once the engine is to temp the hose will get very plyable creating a place where cavitation could occur or even worse ..a kink which would not be good .

Chase

[Iceflyer]

Thanx SkyPirate

Actually the old hose was routed wrong so it rubbed to the engine frame. I will route it differently so it should not rub anything now.

[Av8r3400]

Neither of my 912s have thermostats in them. Unless your 912 is modified to have one, they did not come with one. (Per LEAF and Lockwood seminars at Airventure 2009)

I don't know how to bleed the coolant system or if it even needs to be, so I can't comment there.

[Slyfox]

I agree, just let all the fluid out. There isn't that much anyway. Than you know what you have. The lowest part is the radiator, so release a hose there.

As far as an air bleed, I've never had a problem with getting all the air out. Fill it until it's full. Run it for a few minutes and check it. I went one step further and flew it around the pattern a few times, landed and checked it.

[SkyPirate]

Ahh I forgot ..rotax doesn't use thermostats to eliminate cold siezure proplems ..good call Av8r3400 ^5

Chase

[kitfox2009]

This may be a bit premature when the current temps here in BC are over 34 degrees C but I am pretty sure winter will come again this year. I have problems maintaining water temps during the winter. Experimented with shutters, tape and baffles last year with very mixed results.
Has anyone tried or are using the Thermo-Bob thermostat built for motorcycles.
This would seem to be the answer for uniform engine temps, both winter and summer.
Would appreciate any comments and experiences.

Cheers
Don
Model 5 Vixen 912UL IVO IFA.

[kitfox2009]

Hello All
I am a bit surprised this topic has not received any replies and/or comments. I would think someone must be using these thermostats on their 912`s.
Cheers
Don

[enyaw]

Would be curious to why it is specifically labeled "NOT FOR AIRCRAFT USE"