Hose clips

[Scootles]

I’m in the process of fitting new leg shield trim to my gts300. While in there I’ve noticed a slight weep from a coolant line. (The floor has to come up to allow trim fitting). The whole system is connected with the modern chips which are fitted with special pliers. I’m tempted to replace the ones at the leak site with good quality “jubilee “ clips.
What’s the general view on jubilee vs the modern clip.
PS the trim was damaged when the bike blew over - side stand! You’d think I’d know by now.
Thanks.

[roadster]

There are a couple of types often used as original equipment. The type which is a very tough sprung clip requiring strong pliers or mole grips to squeeze the tangs are in my opinion as good as jubilee clips or arguably better because they can accommodate changes due to temperature or aging. The down side of these is that the hose must be disconnected to fit them.
The type which are machine fitted and have a kind of ladder and notch plus a crimped loop are more susceptible to leaks and I would definitely replace if possible. Jubilee clips when fitted to existing pipes will generally not need re-tightening especially if you grease the worm when fitting.

[Data]

Hi Scootles. Yes, the clip you are talking about is the 'one time use' hose clip fitted to the underfloor coolant hose connection under the floor of the GTS on the left side of the bike. It carries the engine coolant from the cylinder block back to one of the twin radiators behind the glove box at the front of the bike. These clips are in fact a menace & are well known for failing at this coolant junction on the GTS's.

There are some issues when considering a replacement clip. If you use the same type 'one time use' clip again it nearly always leaks as time goes by (usually very soon) since the hose has already been compressed leaving a deep groove around the hose making it difficult to reseal the joint using the same type & size of clip. The special one time use clip applicator won't do the clip up tight enough to seal properly on an old hose. In other words it usually doesn't work. From experience in the trade I can tell you it's difficult trying to get a size of that type of clip to actually fit properly if you try to go down in size slightly. These clips are approximately 9mm in width across the hose clip band; same size of course as the groove in the hose. This also makes it impossible to find any other clip of the worm drive type to fit & seal the hose. The narrowest band on worm drive is usually 12mm, it won't fit in the groove in the hose! Therefore it WILL leak however tight you do it up.

Ok, so the answer we found is to select a QUALITY stainless worm drive clip with the size range 18-24mm & band width of about 12-13mm. The secret to get it to seal is to use an auto coolant resistant sealant that bonds the hose to the plastic connector & then use the clip to hold it firmly together. You must drain the system to do this job properly & take the joint apart to completely dry it. It'll never leak again if you do it right. This sealant is available from eBay or Amazon. It does require 24hrs to set correctly & you must not allow coolant to come into contact with it during that time. I cannot remember the make of the stuff we always used but I'll try to look it up when I go into my garage. It's black in colour & allows you to break the seal anytime in the future should you need to do so. It's widely used in the trade for this sort of job as insurance against leaks. You could use the spring type jubilee clip, again requiring draining of the system to fit it. However, we found those clips seem to damage the rather thin hosing as you do need a very tight fit to seal the joint which does cut into the hose quite a bit. So after experimentation the above worm drive clip & sealant/bonding agent always worked best we found. As professionals we could not afford a coolant joint failure on a customers bike. Also just to be clear, DO NOT lubricate a worm drive clip screw drive as this can increase the chances of failure. The clips are self lubricating as you screw them with a dry thread. I'll post back asap with the name of the sealant. It's a small tube costing about £7.

[Scootles]

Thanks for your replies. I may be taking a big chance here but I’ve left the system alone , with a weep of water - just a trace of dampness - I wasn’t confident that fitting a couple of jubilee clips would sort it and might even have been worse. I don’t expect it to fail catastrophically.
This may come back to haunt me. Data - your technique sounds good, so I would be interested in the name of the sealant. Thanks.

Incidentally - why do the Vespa’s on YouTube come apart and reassemble so easily. My experience was ….. different. Perhaps I’ll get better at it!
Thanks again.

[Data]

I would not leave that joint weeping Scootles. You can lose a lot of coolant very quickly from that joint especialky as you ride. I did! Remember the cooling system is pressurised at 13psi so once warm the coolant can start to spray out under that pressure & from being pumped around. When stationary & cold the leak becomes just a weep & doesn't look too bad. But they only ever get worse. It's not a hard job to fix it. Are you anywhere in Essex? It's an hours work. If you are nearby I could help you out.

[Scootles]

Given the difficulty of spotting and then repairing a leak at this difficult to access joint I’ve decided to take your advice. I found some high temp silicon sealant/adhesive which claims to be compatible with cooling fluids, oil etc. and high temperature. While it’s all in bits I can hopefully do a permanent repair.

Ideally needs coolant replaced anyway according to maintenance schedule, although I wasn’t rushing to do that this week!

Thanks.

[Scootles]

Well I used high temp silicon seal (automotive), waited 24hrs before filling system and the leak persists when hot. Just to clarify the sequence, did you apply the sealant then immediately tighten the clamps, or did you apply the sealant and let it rest for 24 hrs before tightening up? I did the former. Used 18-25 genuine jubilee clips.
I’ll try again in the morning.
On the bright side, the heated grips I fitted during the 24 hr wait are working well. Oxford hot grips touring model.

[Data]

Hi Scootles, sorry to hear it didn't work. It's important to tighten the clip (or clips if you want to fit two) after you have pushed the hoses together. The best way to apply the sealant is to put it over the plastic connector especially at the receiving end of the connector and also put just a little adhesive inside the coolant hose. Make sure to put enough on especially around the indents on the connector pipe. This will make sure the sealant stays in place all along the plastic connector surfaces. Otherwise you simply push the sealant along towards the middle of the connector and there won't be enough to fill the indentations in the plastic connector tube. if you see what I mean. Just one point. How old is the bike? Is the hose still in good condition? Hoses have a finite life (excuse me for saying that as you probably know it) and anytime after 7-8yrs you can expect issues. It may be you have a pin prick hole somewhere around the clip/connector area. Or, you just may not have used enough of the sealant adhesive. Don't use so much that it gets into the hose coolant area after fitting the hose in case a bit breaks off and circulates in the cooling system. That can cause issues.

NOTE: The sealant adhesive we used is: K2 Bond High Temp sealant. It can be used to replace traditional gaskets too.

[Scootles]

Hi Data,
Thanks for responding. Part of my problem, I think, is that the coupling does not have ridges. It has a lip at each end, over which the hose is pushed, but the hose then sits on a perfectly smooth diameter . Despite careful assembly I think much of the sealant is wiped off this smooth surface by the hoses when they are fitted.. I would have preferred ridges to retain sealant and around which the hose could deform to help make a seal.
Presently the system is assembled without sealant, and using two 18-25 jubilee clips - and has remained watertight during approx 20 mins running on tickover, during which the fan came on, so full temperature. I also took it for a hilly 20 mile spin (with spare coolant on board) and it was fine. What I will do is short careful runs while I get confident in my joint. I might have a go with sealant if it leaks again. What I found last night was that the sealant I already have adheres well to plastic and remains flexible if left for a couple of hours. Perhaps a method is to apply the sealant, give it an hour or two to adhere, then assemble and leave for the 24 hours. Perhaps in this way the sealant would not be wiped off during assembly. I would have to achieve smooth even coatings.

Bike is 2020 by the way, in good condition

[Scootles]

PS K2 is on order !