My radiator is leaking quite a bit and I was told it’s a pretty simple thing to replace.
Where do I start? Don’t mind getting something new. Doesn’t need to be stock or anything.
Just want it to work and hopefully install relatively easily.
Thanks
Scott
I know there are “stock appearing” repro radiators out there. WCCC carries some.
Yes, a pretty simple job! I consider myself a novice and I managed to pull it off - twice!
Drain your coolant. There should be a small petcock valve at the bottom of the radiator.
Remove your radiator hoses on the radiator side. They might be stuck on there pretty good if they’ve been on there for a decade or more. You may need to just cut the old ones off and replace them.
Loosen the fan belt by loosening the alternator mounting bolt and remove your fan from the water pump pulley.
Remove the fan shroud from the radiator. Should be four bolts at the corners. Be gentle as they can be fragile.
Remove the top radiator mounting bracket.
Now your radiator should be free and simply sitting in the lower mounting brackets. You should be able to give it a good wiggle to break it loose from the lower brackets and just lift it out.
While it is out, you might consider a few other preventive maintenance items:
Depending on your work area, you may want to stick a hose in the engine and do a bit of a flush on it while everything is apart.
If the radiator is original, you may want to stash it away for the next owner.
Fantastic. Thanks, Mike!
The temperature gauge on the car doesn’t work. Would that be the “engine thermostat?”
Mike didn’t mention disconnecting the transmission cooling lines. Those are often the most difficult to remove due to age. Best to have a “line wrench” to get them cracked loose. You might even need the assistance of a “hot wrench”. I often use a small Bernz-O-Matic torch to heat up the fittings to get them un-stuck.
The thermostat is like a “dam” that blocks the coolant from flowing into the radiator until the engine is up to operating temperature. Then it opens and lets the coolant cycle through the entire system. That is located inside a housing where the upper radiator hose attaches to the engine.
Your gauge not working is likely the sending unit. That looks like a fitting threaded into the intake manifold directly behind the distributor. It will have a single wire going to it. The best time to replace that is while you have the coolant drained when replacing the radiator. Just make sure you get a sending unit for a gauge (sounds like you have one) and not an idiot light. They’ll be different.
The thermostat controls when the fluid that is in the engine is sufficiently hot to require going through the radiator to be cooled.
If your temperature gauge isn’t working, you might want to check the sending unit that is screwed in to the top of the intake manifold. I believe you can ground the wire that is connected to it and observe the gauge in the car. It should go all the way to the high end of the gauge.
Also, you might be able to get your original radiator rebuilt instead of buying a new one. I had my two core rebuilt into a 3 core for better cooling.
Edit: Mark is just a little faster on the keyboard than I am!
Mike described removing a 24" radiator when equipped with a manual transmission.
Mark added the steps required when equipped with an automatic transmission.
If you have the 20" radiator then you will not have the top bracket that Mike mentions, your radiator will have 4 bolts on the sides (each will be close to where the shroud bolts are) that attach the radiator to the support. They are in the corners and are accessed from inside the engine compartment.
Thanks all. I also have an air conditioner. Will that change things?
Just adding that if you don’t have a radiator shroud now is a good time to buy one & add it during reassembly. Personally, I’m a big fan of having the original radiator re-done vs. buying a new one.
I’m having trouble finding a radiator that fits my car. I have a '70 convertible, 351W, auto with a/c. I’m trying to find an aluminum replacement. I’ve ordered two from Jegs that were supposed to be direct fit, but both were too tall (they wouldn’t allow the hood to close). Does anyone have another source or recommendation?
Does it have the 24" radiator like the earlier Cougars? If so … https://www.johnsmustang.com/1967-1968-mustang-radiator-aluminum-8-cyl-small-block-24-rh-lower-hose-high-performance
Yeah, auto trans connections… totally slipped my mind, LOL! Thanks for adding in the other details, guys. I figured there would be stuff I forgot, or details I didn’t know because of model differences - but I knew you guys would chime in with that info too 
Hmm… I bet it will, but I don’t have those answers. Sorry 
Regarding recoring the original radiator ~ nowadays, it seems that costs more than just buying a new one. But if you actually have the original (check your numbers to be sure), and you care about the originality aspect, then that can be a good way to go. My 24" radiator recore cost about $450, and I had to strip and repaint it myself because their paint job was horrible.
I recently had the original radiators redone on both my Cougars & had the exact same experience.
Has anyone (Don?) looked into making an exact FoMoCo RePro?
At $450 for a ReCo I’d think you could make some GooDough
Griffin has exact fit aluminum radiators. On my 428 the height is identical as what was in the car, but it is slightly wider.
Steve
Link?
4-speed lower tanks would be great too!
WCCC has a good video on changing your radiator:
Just watched it. Awesome!
Thanks
I recently reinstalled my stock radiator into my 68 XR7 302 2v C4 auto. I installed new transmission cooling lines and noticed the fittings are missing on my radiator. What size is the male to male fitting necessary to attach the cooling lines, and where can I get them? It is the 24" radiator.