Lower Radiator Hose / Flushing Cooling System

[moss1972]

Todd that was an awesome illustration, thank you for posting that! There is so much great information out there. Some of it you only find after but that's half the fun and really increases the learning experience. Thank you again for sharing!

[wetminkey]

You are quite welcome! Glad that it helps!
It's my pleasure, since a lot of folks do not have access to the Fiat Spider Shop Manual,...I bought mine twenty years ago. They're a bit more expensive now, but I find mine to be invaluable,....

[TX82FIAT]

The hole drill in the t stat is a good option. I have read at some point and I can not recall when or where..... Fill the system and insert a flathead screwdriver in between the t stat and hose and use that to purge air. Personally, I've not needed to do this after filling the system from a high point "T" before hose goes through firewall to the heater and run a few cycles. However, it does seem to make sense in a jam if you have air trapped there.

[moss1972]

The hole drill in the t stat is a good option. I have read at some point and I can not recall when or where..... Fill the system and insert a flathead screwdriver in between the t stat and hose and use that to purge air. Personally, I've not needed to do this after filling the system from a high point "T" before hose goes through firewall to the heater and run a few cycles. However, it does seem to make sense in a jam if you have air trapped there.

Yes that is exactly what we ended up doing. Great trick! We did my brothers 79 this week and had no problem squeezing out the air in the lower hose up into the radiator.

[SteinOnkel]

Neat trick I found if you can loan one of these from your local auto parts store (or you own one):

https://www.oreillyauto.com/detail/b/ev ... 85/4700282

Fill up the system. Just dump it all into the radiator.

Use the above tool to pressurize the system to 16 psi (or whatever your cap is rated for). Wait. Slowly release the pressure, you'll hear it gurgle and spit. Do that again, three times. Pressurize, slowly let it out.

Pop off the tool, top off your radiator. You're done.

Cheers
Steiny

[moss1972]

Neat trick I found if you can loan one of these from your local auto parts store (or you own one):

https://www.oreillyauto.com/detail/b/ev ... 85/4700282

Fill up the system. Just dump it all into the radiator.

Use the above tool to pressurize the system to 16 psi (or whatever your cap is rated for). Wait. Slowly release the pressure, you'll hear it gurgle and spit. Do that again, three times. Pressurize, slowly let it out.

Pop off the tool, top off your radiator. You're done.

Cheers
Steiny

That’s fantastic, This is going to be a fantastic resource thread for people in the future.

[SteinOnkel]

Now I should note that I also have a hole in the t-stat. Not sure if that is relevant or not.

[wetminkey]

I've never replaced my 1979 Fiat T-stat. It works perfectly and I've never had to resort to the gyrations that you guys describe. I follow the Shop Manual recommendations. Fill the radiator and cap it, fill through the passenger's side upper hose (at the coolant T), and then complete the fill from the coolant T's bolt.
I have to add about a cup of coolant to the reservoir after warming the engine, but that's it.
At least ONE THING is easy to get right, every time, on my car!