Leaking SFS Silicon Hoses!

[jjsanz]

Recently bought a set of SFS silicon hoses for a 2004 1.8 K series, wet sump. Kept the same cooling circuit and original thermostat as it was working fine, just changing over to silicon as the old hoses were starting to perish. Fitted all the hoses, fitted a bleed T to the top heater hose, filled with coolant and then the problems started!

 

I'm now struggling to get the bottom hose and J hose to seal properly. The bottom hose to the radiator is particularly bad, even with the engine off and the system cold, you can squeeze the hose and see fluid seeping out.

 

I've tried jubilee and Mikalor clips, the Mikalor ones were worse. I had to swap back to jubilee on the top hose to get a better seal.

 

Anyone else had any problems with these hoses? Any recommendations? I've phoned SFS and they are checking their tooling, the radiator pipes and submarine are all 32mm diameter on mine. Have these ever changed?

 

Any help, greatly appreciated.

 

[Jonathan Kay]

I got mine from Classic Silicone Hoses but SFS have a good reputation and I'm not aware of any size changes.

 

What was the fit like by hand? Mine were all tight except for the thermostat, which was very tight.

 

Do you have the clamps where the thread doesn't bite the outside of the hose? CSH sent those and they were identical to the ones originally used by Caterham, which I reused.

 

Do you use a bit of silicone lubricant? I did.

 

How do you tighten them? Using a hex driver lets you apply the force without the fear of spearing the 7 or yourself with a screwdriver.

 

All of mine were dry first time and haven't needed tightening.

 

Jonathan

 

Edited by - Jonathan Kay on 3 Jun 2013 15:04:38

[jjsanz]

The hoses went on too easily (apart from the J hose onto the thermostat housing). I didn't need to use any grease to ease them on! Makes me think they're too big!!

 

I tried both the worm drive type clips (jubilee) and T bar style (Mikalor), with minimal success. Tried screwdrivers, spanners and socket set! If I tighten them anymore, I fear I'll collapse the pipework or at best strip the threads!

 

[glasgow]

Recently used CC not SBFS... silicone lubricant and Mikalor clips, no problem (K series 2003)

 

Ahmed

[Bob L]

Cut up a cycle inner tube and place that over the outlet, then the silicone hose on top.

[DaveMorris]

The recommendation is, I think, to use lubricant on the connections to ensure that the silicon hose does not bite in one area and form a channel for leak to pass through.

 

Worth a try.

 

I have SFS hoses on Vx and x-flow and no problems,

 

Dave

[Stationary M25 Traveller]

Check the spigots are clean and use silicone grease.

[jjsanz]

Thanks for the feedback.

 

Have spoken to SFS and their sending some different clamps. Will try the tips mentioned here also.

 

If that fails, they've offered to make up some silicon sleeves (similar to the inner tube idea) to plug any gap between the pipework and hoses.

 

Failing that..........

[jjsanz]

Fitted a set of Murray clamps sent over by SFS, they seem to have done the trick. No leaks so far. A big thanks to SFS for their support and to the L7C community for their suggestions.

[andy couchman]

Stretched bicycle inner tube and silicon sealant. Leave to dry and clamp up tight.

 

Than add water and antifreeze.

 

Voila!

 

Andy

[oilyhands]

I've fitted a number of sets. Where the bottom hose meets the metal pipe there are some flats on the pipe, if the jubilee clip sits over the flats rather than on the round part of the pipe it will leak regardless of how tight the hose or clip is. Where the 'J' hose meets the thermostat housing ensure that there is no rubber 'o' ring fitted or again it will always leak..

 

Oily