There is something I don't understand about my radiator. I have a iirc 14-17psi radiator cap with an overflow bottle connected, but when the truck sits and cools, the pressure escapes through one of my hose clamps on usually the lower hose. Is my cap at fault? Should I get a cap with lower psi rating?
I run 50/50 coolant with the oem thermostat, 198*.
Can someone point me in the right direction? I run the truck until fully hot, drive it several miles, and I have no leaks. However, in the morning I find a large puddle of antifreeze beneath the front end. I have an aluminum radiator, if that makes a difference.

 

I would get a cap with a bit less pressure. Also no need for the overflow bottle. Just cover the tubes in the radiator cold and you will be good. The culprit is your clamp, tighten that sucker up! My opinion.

 

My '77 uses a 13 psi cap. If yours is loosing pressure at a hose clamped end of a lower hose, the clamp is loose or the hose has a defect or tear at the end is my guess ... but it could be that the lower hose bib of the radiator has been bent by over tightened screw hose clamping pressure, it gets it's strength by being really "round-round", if ever it has a side just slightly bent inwards from "round-round", it's going to collapse there and not seal. IMHO, spring clamps are kinder to hose bibs than screw clamps in that they spread clamping pressure pretty evenly around the circumference, but a screw clamp can exert greater pressure concentrated near the screw mount.

I'd first drain / save my coolant, then remove the hose at the radiator hose bib and have a good look at that lower hose bib. I don't know how stiff or thick the aluminum is ... but I've never had a crushing experience with OEM brass ones.. If your lower bib is out of round, tightening a screw clamp will only worsen it.

Pressure doesn't fight heat, it doesn't cool, it just increases the temperature that a liquid will boil at and become a gas. 13 psi is enough. I do have a coolant recovery system too, not to cool better, but to preserve my coolant.

 

Thanks to you both. It is always good to learn. I had installed a new inline sensor housing that I installed in the lower hose. I ran it to fully hot, drove it, checked again and no leaks. Next morning I had a puddle of coolant and it was dripping from the where the two hoses joined in the center. (I notched out of each side of the cut hose so that I could slide each end to touch the other in the middle.) Although that may be visually pleasing, it prevents one from seeing where a leak is coming from, I learned. So, drained the rad. Pulled the hoses and housing. Examination of the housing revealed two small voids in the soldier that held the fitting to the housing. I re-soldiered the fitting, trimmed back each end of the cut hose, after applying a bit of sealant. I waited for the sealant to dry, and will now refill the rad and try again.

The housing was made by an old guy who makes efan controllers in his garage. It was a marginal job. I also noticed that the fitting was not installed in the center. On one side there is not enough space between the fitting and the hose ridge for a hose clamp to sit down in. One edge of the clamp rides a bit up on the ridge. We shall see. BTW, my previous radiator cap was 16psi. I have now changed to 13 psi. Thanks.