Hi Guys, Posting this in the hope to get some help in respects to hose clamps. Such a simple subject I know, but I'm really having a hard time with it. I had a major service done on my F355 last year (December), and I've noticed since then that I've had a bit of coolant loss - drips on the ground. This has been getting progressively worse, with it getting so bad I decided to investigate last weekend. After taking off the undertray, it was apparent that there were in fact 2 leaks - from each side adjacent to the radiators, and from high above. Off came the wheel wells, and I found the problem straight away. Both clamps above the radiators were leaking. I was so relieved, I was concerned it was coming from the brand new water pump I had installed during the major. Phew... So anyway, here come my questions.. I had the mechanic use the "T-Bolt" style clamps during the major service, as I changed all the hoses out to those softer silicone ones and I didn't want standard Worm drive clamps chewing up the silicone. The T-Bolts have a solid band which is meant to be better for silicone hoses. Either my mechanic was really sloppy and didn't properly tighten up all these clamps - OR they somehow worked their way loose over time. They were all super loose. What's the go with these types of clamps? Do they loosen off over time to the point where they would leak this badly - or is it more likely they were never tight to begin with? I'm not looking to blame the mechanic but rather understand whether these clamps are appropriate for use. Second question - how damned tight do these things need to be? When I was fixing it, I tightened them up to where you'd think they'd be tight enough. Most of the leaks stopped, but the occasional drip (1 per 10 seconds or so) still occurred. I had to REALLY cinch them down hard before the leaks stopped... Does this sound right? Or am I completely on the wrong path wanting to use T-Bolts as radiator clamps. I'd hate it if that were true because it's going to be a pain swapping them all out now the engine's back in. Told you.. Simple question on a simple subject made complicated.. Thanks guys.
It is not uncommon to have to re-tighten hose clamps. I do it after a road test and re-check after the second. Not unusual to get a couple more turns out of a clamp. Be aware of over tightening. It can cause problems also. Good and snug should be all you need. If you are having to go overly tight..something is wrong.
Definitely agree with you that the screw hose clamps with the open slots into which the outer surface of the hose can get "extruded" are terrible, but they do make the screw style clamps with a smooth band -- for example: https://www.mcmaster.com/products/hose-clamps/worm-drive-clamps-with-smooth-bands-for-soft-hose-and-tube Of course, your local auto parts store won't have them . The T-bolt style should work well, but their downside is the T-bolt hardware is kind of bulky IMO. A few points I would make: 1. Cast ridged nipples can be kind of rough/mis-shapen/have parting lines present/etc. so doing some prep/clean-up with a file is sometimes required. 2. The hose should really be "stretched" a fair bit to go over the nipple and be kind of difficult to get on -- i.e., the clamp shouldn't be the only thing doing the sealing -- are you sure your silicone hose substitutes are the correct ID? 3. Unless the hose is a very thin delicate wall, I prefer the 3/8" wide clamps with rolled edges (not the wider 9/16", 3/4" ones) -- what clamp width are you using? (McMaster does also have the T-bolt style in 3/8" width.)
Thanks for the speedy reply. 1 - Both were brand new - radiators and hoses. 2 - Hoses were sold by a specialist ferrari website (superformance), so I can only assume they were the rights ones.... 3 - The clamps are no where near that wide... These: https://www.tridon.com.au/products/Tridon/35/480/hose-clamps/369544/ttbs-series-t-bolt-all-stainless Thanks chaps.
Don't follow you here. Can you be more specific about which clamp part number? For a size to fit a typical F radiator hose in that link, their widths are 20mm (which is 2X wider than 3/8")
Those certainly are wide clamps. Consider that the pressure placed on the hose would be by area, so with twice the amount of area as a standard clamp, twice the force would be required to seal the pipe. So maybe just crank the heck out of them. One other thing to consider is if the pipe wasn't shiny clean, there would be paths for a drip to get through. More clamp pressure would be required to completely seal it.
I forget the exact size (there's a few different ones with different diameters), but none are near that wide - most are about 1cm wide at most I'd say (same width as worm drive clamps, just with solid steel bands).
Should these clamps work loose over time? I can't believe the mechanic would have left them this loose, not all of them - not unless it was an oversight when the engine was being put back into the car. They weren't just a bit loose - they were all very loose.
I recently did the major service on my 612 and I used Gates PowerGrip clamps on every hose connection that I could reach. In my opinion, they are far superior to any metal hose clamp that I have previously used. Highly recommended.
The OEM type rubber hoses almost weld themselves to the metal over time, which is good for seal but hard for removal without damaging the hose. The silicone hoses won't weld themselves, good for ease of removal but not so good for sealing. Putting some silicone sealer on silicone hoses is not an uncommon way to deal with getting these types of hoses to seal. That is what Dave Helms recommended for his Scuderia Rampante hoses. I used his hoses with the stock OEM Ferrari clamps, which are the Wurth type clamps, and without any sealer, and they are sealing fine.
Thanks all. They all seem tight and dry now (after repeated wrenching), so let's hope that holds. Is it possible that these clamps worked their way loose over time, or is it more likely they were never tightened properly to begin with? As I mentioned they were seriously loose, there was only the slightest resistance on the bolt when I started tightening them - and they were all loose.. Do these T-Bolt type clamps work their way loose over time? I wouldn't have thought so - otherwise you'd see posts all over the interwebs about it. Those shrinking type sleeve type clamps look very interesting, but the f355 has some seriously difficult to access spaces so I don't think they'd be a very good solution.
The clamps are usually put on and tightened with the engine off and cold. The heat softens the hoses up, so they probably were just not tight enough to begin with. The clamps would not loosen over time, but the compression/resiliance of the hose will take a set over time, hence why snugging clamps up over the years is a good practice.
Thanks, that's what I thought... I can only conclude the mechanic didn't tighten them properly during the recent engine-out. It's not as if it was only 1 clamp either.. They were all super loose - 3 different leaks in total. 1 on each radiator and another leak from the rear of the reservoir. The vision of green fluid is burned into my mind.. I need to move on.....
You can tighten the clamps you have. 90% no problem no Brainer. Cat's meow is this... https://www.amazon.com/Gates-32960-PowerGrip-Hose-Clamp/dp/B000CRFJCA Many reasons why these are the best thing going just source in right size.
Thanks... Access is a real issue though, so these wouldn't be the best solution I suspect. Getting them on would be hard enough, but possible with the right extension tube for the heat gun - getting them off though, that would be next to impossible with the official tool. You'd need to very carefully cut them with a razor - but given there's silicon hoses underneath it would be almost impossible not to damage them during the process.... It should be OK now, I'll just keep an eye out for that horrible green monster.
To remove a PowerGrip clamp, you just lightly score it with a soldering iron. After a few passes, it peels right off, without damaging the hose underneath. But this method might be difficult in the hard-to-reach areas. When tightening these clamps, Gates specifies you need to heat a minimum of 1/3 the circumference of the clamp. A full 360-degree heat application is not necessary. The clamps will further tighten as the engine and hoses go through their heat cycles. I was able to make a few "deflector" tips for my heat gun that helped me reach the underside of the hose clamps in tight areas. After several weeks...those clamps are TIGHT! And I have not had a single leak so far.
Many thanks, I might look into those the next time I have an engine out... Right now I just want to put it out of my mind, it was a massively painful exercise sorting it out even ultimately it was ridiculously simple.
Well so far so good. Tightened them down as far as I was willing, and so far no leaks. Will do some more heat cycles and see if it holds up. Thanks all.
Not a huge fan of anything you have to manually crank down on. Me, personally, the hose clamps I've settled on using over here are the Mikalor constant tension spring clamps from Spain. For radiator hoses on my Toyota, I use two constant tension spring clamps in opposing directions, as well as some Permatex Super 300 on the inside of the hoses. Works amazing. Never any leaks, never any maintenance. If the hoses change or age, the clamp will just automatically tighten down upon it further. I love them. Also, before selecting a sealant (which isn't really required, but I wanted to try it out), I tested several products against antifreeze, gasoline, etc. and the Super 300 by Permatex was the clear winner. It really makes a great seal when using those or any clamps. Here are some photos of how I have things setup as far as the clamps on the truck. Not sure if this would help your situation, but thought I would pass along how I'm sealing up my cooling systems these days. Ray Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
This product received 5 star reviews, and here is what one user posted: There are some things to know about them though. On the plus side Very sleek and compact look No parts to rust or corrode Will never need adjustment Can clamp irregular shapes Cons Cannot be removed without needing to be replaced Removal is difficult to do without hurting the hose it is on A little pricey, especially if you have to remove and install often Cannot be used anywhere you cannot get a heat gun all of the way around or close to it
AMEN to that. I had a clamp strip underneath the plenum on my 348. Luckily I could slip an extension bar and socket to tighten periodically to "temporarily" stop the leak (it was a band-aid fix until I had time to remove the plenum and do the job properly). Three-four job to get to a $1 hose clamp and replace it.
Image Unavailable, Please Login I’ve had good luck with this style of clamp. I used them on an application where the engine almost had to be removed to get to the connection. https://www.amazon.com/dp/B00OL237DK/ref=sspa_mw_detail_1?ie=UTF8&psc=1&sp_csd=d2lkZ2V0TmFtZT1zcF9waG9uZV9kZXRhaWwp13NParams
Well it iiissss free shipping. Or for 60% cheaper... 10 Pack Breeze CT-9440 Aero-Seal Constant Torque Liner Clamp with Stainless Screw Effective Diameter Range: 2-1/16" - 3" (52mm - 76mm) https://a.co/d/aWqd45n
