Norma...Constant pressure hose clamps

[missfixit70]

The best ones from the Viper silicone hose site appear to be the Mikalor clamps:
http://www.viperperformance.co.uk/produ ... xscId=9790

I tried those & TBH they were less succesful than standard jubilee clips. They struggled to adopt to the round shape of the external diameter of the silicon hose effectively & they are not constant pressure, so there's no room for expansion contraction as with the original hose clips or the constant pressure ones.

[munroman]

Well done for your efforts Haydn, and as I have said a few times, look at what the manufacturers use, if that has lasted 10 years plus, there is probably not a lot wrong with the design.

The Silicone hoses introduce their own issues, and the heavier Norma clamps look like a good solution to try and counteract the weeping issues.

[missfixit70]

If anyone wants some slightly used silicon hoses to go with the clips , I've got most of a full set cluttering my garage now. (No responsibility accepted for any damage to your bongo as a result of any leaks )

[eoptio]

Hi

I bought some of the Mikalor clamps a few months ago to replace the jubilee clips I used on the silicon hoses, have not got round to fitting them yet. Can I just replace the jubilee clips with the Mikalor ones with coolant in the system or is there a chance of air getting in the sytem and will it need to be bled again afterwards?

K

[missfixit70]

There's a chance you may get air in, worth giving it a bleed after just make sure. Be intersting to see how you get on with them, I wasn't at all impressed with them (mine were the T bolt clamps) in operation although they are fantastically well made sturdy bits of kit, not the right thing for silicon hoses IMO.

[eoptio]

thanks, I'll have a think before trying this. I got the stainless steel t bolt ones, as the jubilee clips sEemed to weather quite quickly thought stainless steel would be better. The look quite well made, interested to know the reason not the right thing for silicon hoses?

k

[munroman]

thanks, I'll have a think before trying this. I got the stainless steel t bolt ones, as the jubilee clips sEemed to weather quite quickly thought stainless steel would be better. The look quite well made, interested to know the reason not the right thing for silicon hoses?

k

From the picture they do not look very circular, so will give different pressures at different parts of the hose, so in effect as you have to have enough pressure to form a seal at the lowest of pressure, the other parts will have too much pressure on the hose and spigot.

So, as the silicone flows under pressure, the coating will flow away from the 'over pressured' areas, this will then reduce the clamping force and the leakage cycle will start. (This will show after a short while by the clamp leaving a deep impression on the hose surface, like really really thick toothpaste the silicone gets squeezed out to the side of the clamp.

A circular spigot, a circular hose, and yet clamping them together with an oval clamp, it doesn't make sense, does it?

[eoptio]

ok thanks, I'd be interested in the Norma clamps in that case, might even remove the silicon hoses altogether and replace them with normal ones.

K

[Ron Miel]

Shucks! Five days before Haydn started this topic (which I've only just seen, anyway), I bought 8 0f the Murray 35-48mm clamps from here http://www.spoox.co.uk/catalog/index.ph ... 61b0f338b8, to use in replacing the four main hoses with silicone.

That's cost me £39 difference + any difference in p & p Anybody tried the Murrays, BTW? From motorsport refs I got, I'm pretty confident about them anyway, but they're even more expensive than Mazda spring clips

Support Haydn peeps!

[missfixit70]

thanks, I'll have a think before trying this. I got the stainless steel t bolt ones, as the jubilee clips sEemed to weather quite quickly thought stainless steel would be better. The look quite well made, interested to know the reason not the right thing for silicon hoses?

k

From the picture they do not look very circular, so will give different pressures at different parts of the hose, so in effect as you have to have enough pressure to form a seal at the lowest of pressure, the other parts will have too much pressure on the hose and spigot.

So, as the silicone flows under pressure, the coating will flow away from the 'over pressured' areas, this will then reduce the clamping force and the leakage cycle will start. (This will show after a short while by the clamp leaving a deep impression on the hose surface, like really really thick toothpaste the silicone gets squeezed out to the side of the clamp.

A circular spigot, a circular hose, and yet clamping them together with an oval clamp, it doesn't make sense, does it?

Couldn't have put it better myself as they are made from stainless steel to a specific shape & the edges are slightly kicked up, there ain't a lot of chance that they are going to adapt to fit the circular shape & apply equal pressure around the entire circumference.
Even with silicon sealant I was still getting weeps, but that coulda been because I was getting a degree of pressurisation from a cracked head, either way, I had to resort to putting jubilee clips on as well.
Bear in mind I've just had to have my head replaced - silicon hose weeps cause or effect? propbably never know, but I have low & high coolant alarms as well as a Mason & a Haydn prototype hi temp alarm as well as a couple of external gauges. I never had an overheat or a catastrophic leak, weeps all through the winter & by June this year I was having to bleed my bongo every time I drove it, just got me home from the bash with the high alarm going - pressurising system, head gone Is it worth the risk? I don't think so. I wasn't prepared to gamble with silicon hoses any longer, so I've gone back to proper Mazda new ones with new proper clamps.

[munroman]

thanks, I'll have a think before trying this. I got the stainless steel t bolt ones, as the jubilee clips sEemed to weather quite quickly thought stainless steel would be better. The look quite well made, interested to know the reason not the right thing for silicon hoses?

k

From the picture they do not look very circular, so will give different pressures at different parts of the hose, so in effect as you have to have enough pressure to form a seal at the lowest of pressure, the other parts will have too much pressure on the hose and spigot.

So, as the silicone flows under pressure, the coating will flow away from the 'over pressured' areas, this will then reduce the clamping force and the leakage cycle will start. (This will show after a short while by the clamp leaving a deep impression on the hose surface, like really really thick toothpaste the silicone gets squeezed out to the side of the clamp.

A circular spigot, a circular hose, and yet clamping them together with an oval clamp, it doesn't make sense, does it?

Couldn't have put it better myself as they are made from stainless steel to a specific shape & the edges are slightly kicked up, there ain't a lot of chance that they are going to adapt to fit the circular shape & apply equal pressure arounf the entire circumference.
Even with silicon sealant I was still getting weeps, but that coulda been because I was getting a degree of pressurisation from a cracked head, either way, I had to resort to putting jubilee clips on as well.
Bear in mind I've just had to have my head replaced - silicon hose weeps cause or effect? propbably never know, but I have low & high coolant alarms as well as a Mason & a Haydn prototype hi temp alarm as well as a couple of external gauges. I never had an overheat or a catastrophic leak, weeps all through the winter & by June this year I was having to bleed my bongo every time I drove it, just got me home from the bash with the high alarm going - pressurising system, head gone Is it worth the risk? I don't think so I wasn't prepared to gamble with silicon hoses any longer, so I've gone back to proper Mazda new ones with new proper clamps.

I would say that you have done the right thing Kirsty, the OEM stuff is tried and tested and the cooling system on the Bongo is not the sort of thing you want to experiment with, no matter how pretty the Silcone hoses look when fitted.

And I hope that you get many more years good service out of your Bongo!

[nfn]

Thanks for sharing your experience with silicone hoses Kirsty -- I think I'm going back to all rubber rather than attempting to get a good seal on the silicone ones.

[Ron Miel]

Shucks! Five days before Haydn started this topic (which I've only just seen, anyway), I bought 8 0f the Murray 35-48mm clamps from here http://www.spoox.co.uk/catalog/index.ph ... 61b0f338b8, to use in replacing the four main hoses with silicone.

That's cost me £39 difference + any difference in p & p Anybody tried the Murrays, BTW? From motorsport refs I got, I'm pretty confident about them anyway, but they're even more expensive than Mazda spring clips

Support Haydn peeps!

Initial performance by the Murray clamps seems good* (http://www.igmaynard.co.uk/bongo/forum/ ... ba#p434819), so perhaps it can be done. Hope Haydn's Norma clamps are materialising, as they're a much better price and look just as capable of doing the job.

*(Any change to that with time, then of course I'll post.)

[mikexgough]

Bear in mind I've just had to have my head replaced - silicon hose weeps cause or effect? propbably never know, but I have low & high coolant alarms as well as a Mason & a Haydn prototype hi temp alarm as well as a couple of external gauges. I never had an overheat or a catastrophic leak, weeps all through the winter & by June this year I was having to bleed my bongo every time I drove it, just got me home from the bash with the high alarm going - pressurising system, head gone Is it worth the risk? I don't think so. I wasn't prepared to gamble with silicon hoses any longer, so I've gone back to proper Mazda new ones with new proper clamps.

Sorry to hear that you had head problems, Kirsty, I guess you will never know it was the Silicon hoses that caused or accelerated the head issue, I did look at getting the Silicon hoses but after the knowledge I have of the cooling system then Factory rubber and decent springband clips are way to go for me.......
My mason chirped off for the 1st time on Friday after a 10 mile, 1 in 3 windy climb..... then the other 6 miles the fans had kicked in and it was only 1 in 4 ups and downs, all was well, no boiling,coolant loss and I drove home from Cumbria to Huntingdon yesterday no worries at all.....

[Ron Miel]

Bear in mind I've just had to have my head replaced - silicon hose weeps cause or effect? propbably never know, but I have low & high coolant alarms as well as a Mason & a Haydn prototype hi temp alarm as well as a couple of external gauges. I never had an overheat or a catastrophic leak, weeps all through the winter & by June this year I was having to bleed my bongo every time I drove it, just got me home from the bash with the high alarm going - pressurising system, head gone Is it worth the risk? I don't think so. I wasn't prepared to gamble with silicon hoses any longer, so I've gone back to proper Mazda new ones with new proper clamps.

Sorry to hear that you had head problems, Kirsty, I guess you will never know it was the Silicon hoses that caused or accelerated the head issue, I did look at getting the Silicon hoses but after the knowledge I have of the cooling system then Factory rubber and decent springband clips are way to go for me.......
My mason chirped off for the 1st time on Friday after a 10 mile, 1 in 3 windy climb..... then the other 6 miles the fans had kicked in and it was only 1 in 4 ups and downs, all was well, no boiling,coolant loss and I drove home from Cumbria to Huntingdon yesterday no worries at all.....

Yes, there's nothing to beat a thrash over some big hills to check out your cooling system is there? If you follow this link http://www.igmaynard.co.uk/bongo/forum/ ... 3d#p434819, you'll see that I successfully did exactly the same on Friday but, somewhat bravely, in torrential rain straight after a full coolant change/system bleed and substitution of silicone for the main hoses.

I've also reinstalled MotorMaxx coolant additive, which I had previously in the old coolant, and which does what it says on the bottle - slight reductions in normal cruising temperatures; big reductions in extreme load (e.g., hill climb) temperatures; reduction, if not elimination, of engine hot spots (no longer any continuing heat gain at the TM2 temp sensor, after stopping the engine).

Mind you, belt and braces - the coolant's also got some of Haydn's Tracerline UV leak detector dye in in it, for good measure