5 replies to this topic

[mattbeddow]

Ok so im replacing the hoses on my engine, theyre mostly perished and id rather not risk them blowing.
Anyway, i cant afford to get silicone hoses at the moment so i was looking at the kevlar ones on minispares but the heater hoses have mostly been replaced by just a standard hose that you cut to length, no shaping.
here's my question, how can i shape them so that the follow the path of the original hoses without kinking or just springing back?
Thanks

[smartie93]

I have these heater hoses,

Not much you can do about springing back, just hold the hose and jubilee clip it. The hose will also bend more than you think before kinking. And after being held in place long enough it will begin to retain that shape due to material creep.

Hope this helps

[dklawson]

If you are trying to make a tight bend on a hose, an old method of preventing collapse is to put a coil spring inside the hose before you bend it. The spring needs to be a relatively close fit to the inside of the hose. If the spring is heavy enough it will hold the shape of the bend when you are done. Regardless of how heavy the spring is, it will keep the hose from collapsing. I have used door closure springs inside places like servo vacuum hoses and heater hoses. Most recently I fit them inside some of the PCV hoses on one of my Triumphs.

[TopCatCustom]

Modern silicone hoses are made by wrapping layers around a mandrel in the finished shape, so they are not straight then bent into shape. I'd think it unlikely that you would be able to bend them into the shape of moulded hoses as the corners are reasonably tight.

[mattbeddow]

Yes, i know that is how silicone hoses are made but the kevlar/rubber ones are usually made as 1 long length and shaped after so i wondered how you can do that at home.
Springs are a good idea, i had also thought about making some kind of frame out of thick wire to hold the corners in shape for a few weeks till the heating/cooling cycles had set the new shape.

[dklawson]

Sorry, I did omit that when you install a spring inside the hose to form it, you leave it there. It becomes a permanent addition to prevent the hose from collapsing.