Constant Tension Hose Clamps

Constant Tension Hose Clamps

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Love 'em or hate 'em, constant tension "spring style" hose clamps are here to stay, and here's why we use them.

I'll admit, constant tension hose clamps aren't the most pleasant to work with, and the larger ones under high tension can be even more of a pain. At, that's all we use, and I'd like to take a moment to explain why.
  1. Simplicity. Doesn't get much simpler than a piece of spring steel wound into the shape of a circle with spring tension. No moving parts, no adjustment necessary; simply tighten it, slide onto the hose, and let it go.
  2. No guesswork. You all know that common German unit of measurement for bolts, "gudentite?" Well, it doesn't work too well for hose clamps, especially those carrying fluids. Overtightening those clamps can strip the adjustment screw, damage the hose itself, or even crack the component being tightened inside. Undertighten them can result in leaks. Furthermore, screw-style hose clamps tend to not apply consistent pressure due to the location of the adjustment mechanism. On the other hand, constant tension spring clamps have only one tension. You can't under-tighten or over-tighten them.
  3. Practical corrosion resistance. Even if a constant tension spring hose clamp corrodes on the outside, at least it will still work (to a point), but adjustment screws can seize, especially in northern states exposed to road salt.
  4. Most importantly: they provide constant tension. An engine bay will typically operate betwen -30F and 200F temperatures, and that means thermal contraction and expansion. This is the biggest reason why OEMs use this style of clamps on just about anything that isn't crimped. Thermal expansion and contraction can cause screw-style hose clamps to loosen over time as they aren't able to take up slack or account for increased pressure, causing them to be too tight when hot and too loose when cold.
For automotive applications, constant tension spring hose clamps simply make the most sense. The reason most people dislike them is that they are a pain to work with in larger sizes, particularly when used in cooling systems. For that, I'd recommend picking up an affordable set of hose clamp pliers, which should be available at your local auto parts store or Amazon. They're designed specifically to tighten these kinds of clamps and hold them open while you work with the clamp and hose.

The constant tension hose clamps included in the PCV fix kits can be easily opened with a pair of multi-purpose (not needle nose) or lineman pliers, and can even be opened and moved by hand using a shop towel to protect your skin. I recommend against replacing those with worm drive hose clamps.

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