RJR

I've never had any problem using worm-drive clamps. Keep in mind that they heat up and expand at fairly close to the same rate as the pipe underneath the hose, so the change in clamping pressure isn't as great as all that.

Generally, for manufacturing, the criteria is (1) adequate for the job, meaning that it will last as long as the hose (or the vehicle warranty), (2) really quick and easy to install, preferably in an automated way, and (3) cheap.

So, just because Toyota doesn't use worm-drive clamps doesn't mean they're worse than the spring clamps, and it doesn't mean they're better. It means the spring clamps are adequate, they install quicker than the worm clamps, and they're cheap. That's really all you can say without reading the engineers' lab notebooks.

scope103

I'm pretty sure that's correct; I don't think heat cycling is an issue with hose clamps.

I have noticed that with some older hoses held with worm-drive clamps, the hose "oozes" through the "gear teeth" in the clamp. I'm not sure that's any different than the permanent mark left in the hose by a spring clamp. But if the hose looks (to me) like it's starting to age, I generally assume that it HAS aged and I replace it. With the same (worm-drive or spring) clamp.

mct75

Would wrapping the hose in something first help with that? Maybe a strip of metal from a beer can? Geeze, I'm way overthinking this.

scope103

I agree. You're overthinking it.

Personally, I would be afraid that if I tried to "line" the hose clamp I would end up with the clamp slipping. There are clamps that seem to have this as a design feature (I'm thinking of Oetiker clamps, which are pretty rare in automotive), but if it was a real improvement some genius would start selling lined worm-gear clamps for $1 extra.

mct75

I ended up reusing two of the spring-type hose clamps on the radiator necks (the truck had two on it to begin with) and buying new worm drive clamps for the remaining 4 joints. So far, over 2 complete heating and cooling cycles, no signs of a leak yet. I reused my coolant, and was surprised at just how little has to be added before the level fills up to the neck, maybe a third of what was drained. There must be a heck of an air lock in there! Of course, I just pump the upper hose and eventually it drains into the block.

Rosco1977

regular hose clamps have always worked for me!!!

bootscootboogie

iTrader: (1)

A roll of Teflon tape isn't very much at home depot. Wrap it around the part the screw will work its way onto, and it would probably work. Either that or some 243 loctite. Let it cure. I'm a cheap man myself. Good luck.

mct75

I thought about it, but the clamps I got have a little metal shield that protects the area. I did wipe a thin film of PB Blaster on the inside of the clamps to prevent them from pinching the hoses as I tightened them. I took the advise here and just barely tightened them. Knock on wood, not a drop has leaked from any of the hoses.

I even added an engine block heater (don't laugh) and so far that's not leaking either.

wyoming9

iTrader: (1)

If your really paranoid about this just use the turbo style clamps ( bolt clamps) and be done

You can get them in just about what ever size you want.

bootscootboogie

iTrader: (1)

I just remembered an old mechanic telling me that any time he did radiator hoses, he would put a thin layer of good old fashioned grease on the mating surfaces, I guess after it dries its kinda like a glue, and its water/coolant resistant. I dunno. Never tried it myself.

RAD4Runner

Hi guys,
I hope you all had a fine Thanksgiving weekend.
Glad to find this page. Since my engine was rebuilt and all cooking components were replaced (in 2013), I never saw any leaks - even after 8-hour long drives.

However, the morning after Thanksgiving, I saw coolant dripping under upper radiator hose where it is clamped at radiator neck (see below). I re- tightened and checked when we got back to San Diego tonight. So far, no leaks

This could have been because of combination of:
(1) After-market constant-tension worm-drive hose clamp,
(2) Almost freezing temp in Las Vegas these past few days, making materials shrink when they cooled after a 6-hour drive, AND
(3) Hose looking like under tension (I may have to replace with something that would have more slack.)

So now I'm leaning toward replacing the worm-drive clamp (where hose material starts to squeeze through the slots/threads) with either OEM or Spring-Loaded ones like this from McMaster-Carr
Have you guys had any experience with the McMaster one?

Terrys87

iTrader: (1)

I have not seen a McMaster clamp. It does seem like when I replace a hose at some time later I do need to go back and retighten it.

RAD4Runner

Thanks, Terry.

I think, like many people say, retightening is a necessary maintenance item for worm-drive clamps. That's fine with metal radiator fittings but I would be wary with plastic ones. I would just use a "lined" one where the un-threaded/un-slotted part of the metal strip extends under the slotted part (like on the McMaster one pictured below). This way, hose rubber would not get extruded through the slots.
McMaster Clamp looks like below.

mct75

Not that it helps, but I reused two of my OEM spring clamps on the plastic necks, and bought new, basic worm drive clamps for the other 4. No issues aside from having to retighten one of the worm drive clamps.

RAD4Runner

Makes sense and agrees with what many people are saying.
Clamps with give like OEM good for plastic connectors, and rigid worm-drive OK for steel connections but need to be retightened as the hose material compresses.

RAD4Runner

Above post shows how my radiator end of my upper radiator hose had to be re-tightened. It happened after we drove to Las Vegas when it was significantly colder than San Diego.

Last weekend, I parked my truck at trailhead where it went below freezing. When I checked today, I saw coolant drips and found a pool of it below where upper radiator hose connects to thermostat housing "elbow". Yes, that end of the hose is wet. I'l retighten and monitor.
Could it be possible that extreme (by west coast standards) cooling and heating of these parts cause rubber to shrink or make it lose its ability to bounce back?

scope103

I know i expressed the opinion (in this thread!) that worm-drive clamps might be better than spring clamps. But since then, I came across a source that clearly disagreed (I know, I know .. without the cite my recollection is suspect). The argument was that spring clamps hold a (relatively) constant pressure, whereas worm drive clamps hold a constant diameter and will change pressure with temperature changes.

You can get a set of 100 OEM-style clamps (in different sizes) for $12 delivered. https://www.aliexpress.com/item/100p...833084012.html You might measure your radiator input; if it's 22mm or less this could be an option.

87-4runner

hey rad... living in oklahoma its -10 one day and 70 the next... been using screw clamps for 50 years with very few problems... occasionally need some tightening, occasionally over tightened and ruined or pinched a hose... but overall they've served me well... i do try to buy gates hoses whenever possible...
I'm sure O'Reilly gets wore out from me digging thru the hoses to find one with the right bends, od, id, that i can modify... regardless of application.

snippits

My local NAPA stocks Ideal Tridon Flex-Gear 47 behind the counter. These clamps solved all of my radiator hoses cold leak problems on my 22RE

It's a Belleville spring design that maintains constant tension, and they are all stainless. Cost round about $5.50 each.

http://idealtridon.com/aftermarket/f.../flex-gear-47/

RAD4Runner

I tend to agree with Scope103...
(The hose with OEM clamp (like the aliexpress above ) to power steering fluid reservoir - which is a low pressure line - of a friend's Camry. Worm-drive clamp fixed it.)
However, I understand that worm-drives need to be adjusted occasionally.
Therefore, I think the Tridon Flex-Gear 47 has the spring load and adjustability at the same time. $6 is a fair price so use on a high-pressure, high-temp line. Will check it out next time I'm near Napa.