Radiator swap almost done

Hello all, I’m a real newbie that decided to take on a simple project and one thing lead to another, but I feel like I’m close to finalizing this weekend, if it ever stops raining here in California.

I was swapping out a leaking radiator on my '67 289 C4 automatic and adding a fan shroud while I’m in there. However, I managed to break the transmission cooling lines in the process as well as some of those fittings. WCCC has been super helpful getting everything I need, and I’m awaiting a new, shorter fan spacer, which should be the final ingredient to finish this job. I hope.

I have 3 questions, in the hope of not running into any more compounding issues.

  1. I have a belt-driven fan (not a fan clutch) … should I loosen or remove the fan belt (or… belts? I have 3?) before swapping out the fan spacer? It doesn’t seem like it would be necessary, but it was a step I saw listed somewhere.
  2. When refilling the radiator, are there any good, proven methods for ensuring there’s no air in the cooling system?
  3. Similarly, when I’m topping off the transmission fluid (type F, right?), is there any concern with introducing air into that system … or anything else I should be considering with the transmission fluid?

Thanks in advance for any wisdom. I’ve been lurking on this site since I purchased my cat a year ago, and it is amazing to have access to such a wealth of knowledge and resources from this community.


Loosen the belt tension will help with R&R of the spacer. Depending on how much shorter the new spacer is you may need new fasteners. If you do, note that they are fine thread not coarse thread when selecting new bolts.

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As far as Question 2 ( 1. When refilling the radiator, are there any good, proven methods for ensuring there’s no air in the cooling system?)

Old school way…elevate the front of the car ( I just pull up on the ramps) cap off radiator, heater on full, let run and watch the radiator fluid cycle. A couple of minutes and your done.

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Already up on the ramps, so that sounds good. Thank you!

Sure. Drill a 3/32" hole in the thermostat. Put the hole at 12:00.

I never circled back with the end result, but everything worked out well. New radiator, shroud, fan spacer, and transmission cooling lines/fittings. Took more than the one Saturday I had originally anticipated, but she’s been staying cool and running smooth for a few months now.

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