Hardlymoving writes about do-it-yourself automobile maintenance on various makes and models.
Three Types of Hose Clamps
I'm writing about three different types of clamps used on cooling systems in cars because I see that sometimes mechanics doing repairs on your car don't use the best, longest-lasting kind.
Spring Clamps (Constant-Tension Clamps)
On most automobiles as they come from the factory, the hoses in the cooling system are connected, fastened, and sealed from coolant leakage by spring clamps (also called constant-tension clamps). They are commonly referred to as spring clamps because they apply constant tension on the rubber hose. Automobile manufacturers use spring clamps on cooling system hoses because haven't found a better or cheaper way to apply tension to the hose regardless of the hose's condition. This matters because as the hoses age, they may harden, soften, swell, or lose their structural rigidity, and spring clamps will continue to apply force on the hose regardless of the condition of the hose.
I do have an issue with plastic compression ring clamps that are force-fitted onto the hose. These plastic clamps can't be serviced, and when I work on cars like this, I have to cut or saw off these plastic clamps and replace them with a serviceable clamp.
Worm Clamps: An Inferior Alternative
When I am working on a leaking cooling system, often I am annoyed to find that some mechanic has replaced the original factory spring clamp (let's say an upper or lower radiator hose clamp) with a worm clamp. The mechanic probably went for the worm clamp because he didn't have the right tools to get the clamp off and didn't want to go through the hassle of putting the original clamp back on. Worm clamps are substandard compared to spring clamps because they fray the hose with the adjustment slots, they can strip, they can cut into the hose, they may not be able to apply adequate tension to prevent leaks, and they don't compensate the shrinkage of the rubber. So worm clamps are likely to lead to leaks in the future.
Racing Clamps: A Compromise
A good compromise between spring and worm clamps are racing clamps (or t-bolt clamps). Racing clamps have none of the shortcomings of worm clamps. They're easy to get off, mostly made of stainless steel, provide 360 degrees of wide tension, and are very durable. I have occasionally used these as backup for weak spring clamps. But keep in mind that racing clamps do lose their tension sometimes. Also they are expensive, and not available at parts stores.
Video: Different Types of Hose Clamps, and Tools Used to Remove Them
The following 3-minute video will explain the tools used for removing factory original spring clamps and compare them with two other aftermarket hose clamps (worm clamps and t-bolt clamps).
This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.
Questions & Answers
Question: I agree the worm clamps are inferior to the spring clamps. However, there are worm clamps and worm clamps. The one showed in the picture has adjustment slots. But the worm clamps I buy here in Holland do not have adjustment slots. Therefore they don't really damage the hose. For whatever reason I have never seen worm clamps without slots for sale while I was in the US. Not sure why that is?
Answer: Yes, you are correct. I have seen non-slotted worm clamps on both European and Japanese cars that are factory installed clamps ... not aftermarket. They do seem to be better. For larger clamp applications (that is radiator hoses), I go out of my way to get t-bolt (racing) clamps. More clamp surface area and uniform pressure ... in my opinion. They're available from various vendors on Ebay but non to be found locally where I live.
Question: Are there any content tension clamp removal tools that are somewhat reasonably priced and yet very reliable?
Answer: Yes ... there are good prices on Ebay ... you'll need to shop for the best prices.
© 2018 hardlymoving
hardlymoving (author) from Memphis, TN on January 25, 2020:
With new hoses, the hose may give a little and the worm clamps must be re-tighten or they'll be leakage.
bhattuc on January 25, 2020:
Very informative. My experience is with worm clamps only. They are good in many situation.
hardlymoving (author) from Memphis, TN on March 29, 2019:
I'm with you brother. Seen too many independent shops struggling getting the spring clamps off because they don't have a spring clamp tool(s)... so come time to clamp on the hose, they revert back to aftermarket worm clamps.
Automotive engineer on March 29, 2019:
Spring tension coolant clamps as defined are the highest quality solution at this date and time.