Radiator failure due to frame flexing?

[dbbowen]

im late to this thread, but you are absolutely correct. In my 60 i went through 3 aluminum FSR radiators in 3 years. The tubes would pull out of the end tanks on the upper right or upper left side of the radiator. It looked like electrolysis because the leaks would be tiny and then get discolored. The stretching would produce tiny cracks in the radiator tubes.

This is specifically due to the truck body pulling the top of the radiator apart and thermal expansion making the material weak. Specifically the core support twisting. The older brass radiators have some give to them since the material can bend and flex. Aluminum just cracks. thats why you see 30 year old oem radiators still kicking

I worked with the owner of FSR to develop a radiator that has reliefs in the upper cross support to allow a few mm of flex if you want i can take some pics of it when i get home from work. Its been over a year now and this radiator has no signs of the tubes pulling out

 

[86aggie]

It went in fine per the mechanic. He made sure there was no twisting or binding as he bolted it in. Shroud is square. No offroading ever - I've owned it since it was new.

 

[wngrog]

Ok. Maybe you have the wrong fan. Some of the plastic fans don’t have enough backspacing and are too close to the radiator.

I had this issue trying to get a fan clutch into a no fan clutch application and @cruiseroutfit found me a fan with about 1.5” more backspace than the standard 60 fan

 

[dbbowen]

It went in fine per the mechanic. He made sure there was no twisting or binding as he bolted it in. Shroud is square. No offroading ever - I've owned it since it was new.

Yep same here. Either The truck is pulling it apart laterally or its thermal expansion, or it’s both. My frame has an extra support up front bracing the two frame rails together via an additional rigid welded crossmember as well and it still pulls them apart. I even bought all new oem Toyota rubber isolators for all of the mounting points and all new Toyota bolts.

Here is an image of my current radiator with the expansion slots that I was talking about earlier. The driver side tanks are welded like normal, but the passenger side is left unwelded and is under tension from the bolts but is allowed to stretch a little and expand and contract. The bottom of the radiator has this as well.

As you can see. The tubes have zero sign of wear after a year. I do wheel my truck and have had no issues with this one finally. 3rd times the charm

 

[dbbowen]

This is opposed to what it looks like after the radiator is pulled apart laterally with fatigued tubes. The aluminum is suuuuuper thin on these tubes so it doesn’t take much to crack them. The coolant was tested, voltage tested, and the rad is grounded. I used to use a sacrificial anode rad cap too. 100% ruled out electrolysis on my situation.

I had 2 radiators do this. One on the driver side and the other on the passenger side. Don’t want to jynx it. But it seems to be fixed now with this new one. Green coolant, red coolant doesn’t matter. Used them both and had the same issues