Hey Chaps,

I noticed the other day my coolant hoses are weeping, if they are the originals them that would make them 10 yrs old so would sound about right.

Now, my 2 options are either Yamaha or AS3 http://www.as3performance.co.uk/yama...r-hoses-black/

I asked on another group and someone said the OATs coolant will eat the AS3 hoses. Has anyone had any experience with the AS3 kit or know of a suitable replacement coolant for the XTR?

I have a vague recollection that for some reason silicon hoses aren't good. Can't for the life of me remember why but may have something to do with the type of coolant. Hopefully someone else in the know could shed some light on it.
(Sorry for the half ar5ed answer!)

Organic Acid Technolgy (OAT) coolant's main anti-corrosion inhibitor is either sodium or Potassium 2-ethylhexanoate which form ethylhexanoic acid and that is what is incompatible with silicone Rubber. Ethylhexanoic acid will slowly eat away at the silicone of the hose.

Fluorosilicone hoses are compatible with OAT coolant, but 99% of all silicone hoses on the market are not made from this primarily because it is more than three times as expensive as standard silicone.

You would be ill-advised to use old fashioned Inorganic Acid Technology (IAT) coolant as its anti-corrosion properties rely on it building up a layer of silates on the internal surfaces of the cooling system. This layer of silicates is not good for the longevity of mechanical water pump seals on pumps designed to run with OAT coolants.

You basically have three options: (1) Find some hoses that are fluorosilicone (state that they are 'OAT Safe'). (2) Find an OAT based coolant that states it specifically excludes 2-EHA. There are some just coming on to the market but they are very expensive and hard to find. (3) Stick with the OE hoses and get another ten years of use without the added complexities.

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Next question then does anyone know a cheap source of the OE hoses?

A complete set of three OE hoses (top, bottom and water pump bypass) is �50 from a dealer... �10 cheaper than the set of AS3 silicone hoses you were originally considering which almost certainly won't last as long as your originals!

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I'll give my dealer a call, I tried aj suttons and that looked expensive

It's up to you. If you think their claims are substantiated then get some. I just couldn't see any evidence (or claim) on their site/shop that they are OAT safe.

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Hopefully you can see it in this picture

Attached Images

image.jpeg (21.6 KB, 10 views)

I assume you mean the blue lining? If that is a fluoro-liner, then you should be good to go. Have you actually had it from the horse's mouth, so to speak, that they are fluoro-lined?

What's odd is that, if they are fluoro-lined, why is there no mention of it on their web site, and why does it state "made from pure silicone" in the blurb?

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I've not heard it yet but did ask with a open question. If it turns out these really are suitable I'll report back.