Here's a few interesting thoughts on rads. I had rad leaks in my low miles '86 E350. Upper tank buldge and leaks at the top of the tubes at the upper tank. I fixed it twice at home but it always wept in a new place in the upper tank area. I now have a new rad.
Here is the story I got from my rad shop. This shop by the way, does commercial and retail for a large area has been in business for years and has an excellent reputation. Early Ford rads for this truck/van application had too small an opening in the rad tubes, with age or leak seal these tubes restricted even more. When the thermostat opens and that big pump dumps a large surge of hot coolant into the top tank the tubes can't take it fast enough, the pressure gets extreme in the upper tank, it buldges and the tube seams let go. Sure enough the engine side of my upper tank was buldged out slightly. I was also told that Ford, instead of replacing rads with a larger tube flow rad just reissued a new thermostat that restricted the flow to the top tank so volume stayed down. Now, this works if your tubes stay clean but with use and maybe stop leak these tubes restrict. If you tow, and at the limit in warm climates, this is your fate.
It is nice to pass along information that helps others. Great forum!
Here is the story I got from my rad shop. This shop by the way, does commercial and retail for a large area has been in business for years and has an excellent reputation. Early Ford rads for this truck/van application had too small an opening in the rad tubes, with age or leak seal these tubes restricted even more. When the thermostat opens and that big pump dumps a large surge of hot coolant into the top tank the tubes can't take it fast enough, the pressure gets extreme in the upper tank, it buldges and the tube seams let go. Sure enough the engine side of my upper tank was buldged out slightly. I was also told that Ford, instead of replacing rads with a larger tube flow rad just reissued a new thermostat that restricted the flow to the top tank so volume stayed down. Now, this works if your tubes stay clean but with use and maybe stop leak these tubes restrict. If you tow, and at the limit in warm climates, this is your fate.
It is nice to pass along information that helps others. Great forum!
