5window

Ok. Yes, I have done a search first and looked at all 370 relevant posts. So, I have a '65 200 CI six with the auto transmission and a stock,original radiator. The radiator started to leak, badly, even when the car was not running and,fortunately, we still have a long time radiator repair shop nearby.

After doing quite bit of re-soldering, the guy sent it back with a 7# cap, replacing the non-original 13# cap that was on it and insisted this was correct.

Most of the previous posts on this subject suggest 13-14#, but nowhere can I find what the original Ford recommendations were. Maybe 13# was the reason it failed in the first place (or it's 50 year sold). Any help? Thanks.

Tilley

I believe the science of cars in the 1960's is not as good as today. I do believe the caps then were 7lbs, but then again, the thermostats were 195 degrees. By the time the radiator got to operating temps, there was greater than 7lbs of pressure in the radiator. Cars were always dumping water out. I remember it wasn't uncommon to check the radiator every week.

I have used a 7 pound cap, and it just made a huge mess on the street. I have also used a 16-18 pound cap too, but this made my car run a little hotter. Since then I have used a 13 pounder on my 1965 I6'er and have had good results.

The modern aluminum 2-row radiators are much more efficient AND durable than the old rads. I have bought two "Champion Radiators" for my Mustang and 1962 Ranchero and can't say enough about the quality and efficiency of their product. It is also relatively inexpensive. Champion also has a lifetime replacement warranty. You can't beat that.

barnett468

if your rad leaked because it hsad a 13 lb cap your rad is a pos.

also it means your car is overheating and needs repairs.

a 7 lb will puke all over if your water level is too high.

5window

Thanks for your insight.

67mustang302

Just replace the radiator with a good one. Champion makes excellent radiators, I'm using a 4-row.

There are very few old radiators that are worth repairing, and a 6-cyl radiator is not one of them.

Tilley

I agree 100%. I have gone through at least five stock radiators in less than a year. The reason why they leak so easily is because they are epoxied at the seems instead of welded. They also have some non-aluminum parts (plastic) inside. The Champion radiators are all aluminum and welded at the seems.

I do not have stock in Champion, but I wish I knew then what I know now. The stock radiators are extremely cheaply made, and the Champions are really nice. The price for a 2-row is about $165.00. You could go with a three row but you will need to get rid of the fan spacer for the rad to fit. Also, you will need to buy a shroud. There are really 2 types: the metal stock ones that go for about $25 at JEGS, or a $100 three inch fiberglass shroud.

I have another thread which goes in much greater detail. The cost is about $500 to do what I did to get my car to run cooler and be consistant.

https://mustangforums.com/forum/clas...-i6-motor.html

Hope this helps.

5window

Thanks. I may well have to go the replacement radiator route, if this doesn't work. However, this is a basically stock,original car which was owned by my aunt from the day she bought it in early '65 until the day she gave it to me last November. I am hoping to keep it as original as possible.