Back pressure in coolant system?

[Mike534x]

After seeing a post made by Tollkeeper, it reminded me to ask about this. I've been having issues with my upper radiator hose backing off where it connects up top. I tried replacing the radiator cap, upper and lower hoses with ones made by Gates. The upper one was "fudged" in the sense the previous owner cut it to make it fit?? The lower one was similar in butchering. I ordered those up and put them in last summer. I replaced the upper and lower hose clamps as well, but for some reason the lower hose comes loose every once in a while, but for the upper its usually every week, or every other week that I need to loosen the clamp and "push" it back into place.

There's not cracks or anything in the neck for the rad that I can see causing this, so I'm not sure if the radiator cap is bad, or if there is back pressure being created somewhere in the system.

 

[Mounce]

There's definitely pressure in the system, up to about 15psi when fully warm. Designed to pressurize with temperature.

Maybe you're not tightening the hose clamp enough?

 

[m.mcmillen]

If you’re using spring clamps, they might be weak.

 

[Mooseman]

If using worm clamps, I have found that some do back off and have to be retightened, or it's the rubber that compresses a bit making it seem like the clamps are loosening. Try using two clamps.

 

[Mike534x]

I was using HF's worm clamps originally, the ones connected to the t-stat are still secure. I do have the top and lower ones as tight as they can be without damaging anything. I switched to a set from O'Reilly thats a worm style one but with a ring/band that goes over the hose and seems to give it added "clamping" around the neck. I swapped the HF one two weeks ago at the radiator for this newer one, and when I got to work I was smelling AF. Propped the hood up and found a small puddle with the hose backed off about 5/8 in from that small nub that keeps you from pushing the hose up further. So I loosened the clamp a bit, pulled the hose back up and tightened just a bit harder.

I was running two clamps before swapping the upper hose, and it was still backing off, which made me think it was an issue with the hose the PO installed/butchered. My next step is maybe throwing the OEM style one back in.