Do constant tension hose clamps lose their clamping ability over the years?

MasterSolenoid said:
Use the right tool for the job.
These Hose Clamp Pliers are great to use.
https://www.acmetools.com/craftsman-hose-clamp-pliers-cmmt14136/S0000000081288.html
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Honestly when I don't need the remote access or right angle ability of the cables, my favorites have quickly become the big pliers style with the flat waffle jaws. Incredibly versatile and not finicky about placement on the clamp ears.

But yeah, I'm a believer in having EVERY style tool for constant tension clamps -- each situation is different.
 
Lubener said:
Any spring will loose tension over time.
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No. That's not the case, though it is a common misperception and the source of many "bro science" things like "don't leave ammo in your magazine or it will cause the springs to lose tension". The spring will have a very short period at which it will lose load as it initially settles, but once it's installed and had a couple thermal cycles, the metallurgy of the spring does not change.

Tension loss is a metal fatigue phenomenon and metal fatigue requires plastic deformation (yielding). Which spring tempers are specifically designed to reduce.

Now the hose it's clamping? ABSOLUTELY is changing over time.


It's not that your clamps are getting loose. It's that your hoses are degrading.
 
The spring clamps on my Focus simply rusted too much and broke, but they held leak free until then. The clamps on mine broke on the bottom side but stayed on looking not too bad on top and just producing a small drip under pressure.
I left the hoses as they didn't have any cracking and put on some hose clamps, as they lasted 20 years and I only need them for a few more months. Also the thermostat end is buried in the Focus, requiring taking off the intake, or your could take off the power steering pump pulley...
 
Hohn said:
No. That's not the case, though it is a common misperception and the source of many "bro science" things like "don't leave ammo in your magazine or it will cause the springs to lose tension". The spring will have a very short period at which it will lose load as it initially settles, but once it's installed and had a couple thermal cycles, the metallurgy of the spring does not change.

Tension loss is a metal fatigue phenomenon and metal fatigue requires plastic deformation (yielding). Which spring tempers are specifically designed to reduce.

Now the hose it's clamping? ABSOLUTELY is changing over time.


It's not that your clamps are getting loose. It's that your hoses are degrading.
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No, you missed the entire metallurgical phenomenon's of metal creep, and micro cracking of the tempering.

You can calculate the creep if you had the needed constants for that alloy. The micro cracking I don't think there is a good way to predict.

I have had this happen - and pure speculation but I imagine the combination of long term creep followed by the rapid expansion to remove the spring causes micro cracking. I have had these springs clearly loose their strength, and even had one snap which made for all kinds of fun getting it off.

I imagine they use the cheapest alloy and fastest possible heat treat on a 10 cent production cost spring clamp. There are all different kinds of spring steel and processes to get it there.
 
Bailey28 said:
I went through a life learning episode with these factory spring clamps on a Kia Sorento. At 60k I decided to remove the upper hose and flush the radiator. Upon replacing the spring clamp in a slightly different position it leaked coolant.

If you remove the clamp it has to go back EXACTLY where it was before. If your clamp lost tension and is leaking and you try another one, it has to nest into the imprinted area the previous clamp made on that specific hose.

If you use new hoses you get to 'start over' and the clamp can probably go anywhere on the bung.
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Been working on Hyundais during a dark period in my life, I can attest to the above
 
The springs in an old fashioned mechanical clock will lose their tension over the years. This is known as being "set."
Leaving them fully wound in storage will cause it to happen sooner.
Of course the quality of the spring does affect this. So springs arguably can, and do lose their tension over time.
Many clock springs can be over a century old, but are not subject to the temperature extremes seen under a car's hood.
 
zrxkawboy said:
A related question: anyone have a good source for new spring clamps, other than OEM?
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good question. I wonder if these can be gotten from the dealer? All my spring clamps are a light grey color and not a spec of rust. I see a ton that are a dark grey graphite color and I question the quality and corrosion resistance. These particular hoses also seem different than your basic heater hose type coolant hose. They're like a double layer hose. Red on the inside and a shiny grey on the outside. Silicone possibly?
 
Rubber begins to compress faster/more significantly than spring steel creeps (elastic relaxation, visco plastic, whatever you want to call the phenominon) at low temperature.

That's right. Underhood temps are low in the regime of creep initiation.
 
Some engineers who should know better claim that the equations covering springs in general do not include time, meaning the spring should always function without change. In the real world, things corrode, metal fatigues and gets brittle, etc.

Carroll Smith warned against using or reusing spring clamps in his racing books.

That said, I'll reuse a clamp that seems solid and as tight as it had been, but the next time I change the hose, I check the clamp again. If the clamp is getting rusty, it's time to change it.
 
I noticed this past weekend at a Ford display their engines looked to be using worm drive clamps again instead of the spring clamps that were typical for the past 30 years. Unless they are some type of hybrid clamp is that the direction things are moving now?
 
The motor guy said:
good question. I wonder if these can be gotten from the dealer? All my spring clamps are a light grey color and not a spec of rust. I see a ton that are a dark grey graphite color and I question the quality and corrosion resistance. These particular hoses also seem different than your basic heater hose type coolant hose. They're like a double layer hose. Red on the inside and a shiny grey on the outside. Silicone possibly?
Click to expand...
I get my Nissan clamps from the dealer. Well online dealer. Pricing is all over the map. From like a buck for a small one, I think they want close to $10 for the rad hose clamps. Still, $10 for no leak is a good deal I guess.

I will happily re-use a clamp if it comes of straight and shows not sign of fatigue but I do like to have them around JIC. I tried ordering a selection of Chinese clamps from somewhere and they had so little tension I am unsure how they would seal anything.
 
I have worm drive clamps I bought at a flea market years ago that have the "Ford" logo imprinted on them. They were made by Tridon.

20250821_071358.webp
 
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