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Coolant change interval - how long is too long?

Discussion in 'Maintenance and Servicing' at netrider.net.au started by Sitting Bull, Dec 31, 2014.

  1. Question, would you buy a 2006 FJR1300A that's done nearly 20000kms with no record of a coolant change? Service records at 10K and 15K show it was checked. 15K was over 4 years ago and it's been sitting in the shed unregistered until last month. What I've managed to find is that most people are changing coolant every two years and the service schedule states every 3 years. I know it's a risk but how much of a risk?

  2. I don't think it is a big deal.

    more importantly break fluid will need to be flushed and the break system inspected.
  3. I'd have to agree with Iclint. I've never heard of problems with aged coolant. Though probably it's anti corrosion properties decline with age. Better question is there enough. In fact it's almost a help, if it'll start and you get it fully warmed up you can then check the colour, if it ain't green (or some are blue) but oily or rusty &c... Like when a leak goes the other way and your oil goes milky.
    Like Iclint said check the brakes. If it's been sitting for years there could be water in the brake fluid (it attracts water) which can corrode the bores and then rubber bits harden & leak. Same with clutch if it's hydraulic.
  4. I like to change coolant every 12 or
    Anti corrosion suffers and as much as people don't think it, coolant is a lubricant. It lubricates pump components as it passes through. All lubricants break down over time.
  5. No worries, I'll check the brake and clutch fluid. I did read somewhere that leaving coolant change too long can lead to problems but it wasn't stated what they were. Corrosion anywhere in the cooling system can't be a good thing. The coolant level looked OK and green in colour when the bike was cold. I will be checking it over thoroughly if I decide to go back for a second look.
  6. Yeah that was something in the back of my mind. Water pump impellers are usually rubber. I know a few cars that if you have covers off to check or change cam belts then you just replace the water pump as a matter of course while you're in there.
  7. #7 jstava, Dec 31, 2014
    Last edited: Dec 31, 2014
    In a perfect world where the metals used throughout the cooling system were all completely compatible, no fluid was ever lost and the coolant consisted only of de-ionised or distilled water and ethylene glycol, it should go on and on, BUT people introduce ions into the coolant solution when they top it up and parts are replaced, some metal parts wear (notably in the water pump), or corrode over time (the cap), or a gasket starts to break down exposing metal parts which were never meant to come onto contact with the cooling water. Any of these can expose different metals to the solution and introduce metal ions. Then you have corrosion due to electrolytic effects of different metals exposed to the coolant solution. Notwithstanding, there are often dissimilar metals built in, eg. if you have a copper radiator and alloy engine, or you've fitted an aftermarket radiator after damage, or the inside of metal reinforced hoses begins to break down exposing, the coolant to the metal.

    Short answer? Coolant is best changed annually. Like oil changes recommended at 10K? Lots of people halve this, and benefit from engine longevity. I think 3 years as a maximum interval. The best way to ensure that you are getting quality stuff is to buy the concentrated Ethylene Glycol and mix it with deionized water in the recommended proportions. The best reason for doing this (change regularly) is to monitor whether corrosion is occurring in your engine. If not, the coolant will come out looking like it came in (if so, you could re-use it! but only if it is collected in a clean container and not contaminated) if it's cloudy or full of gunk you have a developing problem which you can forestall a secondary problem of this gunk building up and restricting coolant flow through all of the galleries it needs to move through to cool the engine. Meanwhile, what is causing this? Possible causes above OR the manufacturers have included a mix of metals in the manufacture of the machine which will eventually leave one part with a problem. This is least likely, though it is not so unusual for some builders to include a "sacrificial anode" part - usually a gasketted hose fitting, or the water pump (planned obsolescence?) These often will corrode away and begin to leak first. The upside is the main metal of your engine is preserved as a result of this.

    Once a year. You get to look at the fluid, whether it contains a "load". You can flush it with rainwater if you don't want to use ion laden tap or bore water, then refill. This is good preventative medicine for cooling systems. Pure water does not contain ions and does not conduct - be anal about this. The quality of your water is crucial in overcoming any differences in the activity of the metals the coolant touches inside the engine. If it is perfectly clear, lengthen the interval. How long is a piece of string?

    If it's all grotty and got gunk, be careful about using radiator flush products. They need to be used strictly according to instructions AND flushed and rinsed completely from the system. This is painstaking stuff, but if there is residue, it can make the corrosion problem worse, by leaving ions in the system. The coolant needs to be as poor an electrical conductor as possible to avoid corrosion. This means pure water and ethylene glycol only.

    This is not short. I am sorry. If you are only going to keep your bike a short number of years it's probably not an issue at all. If you started with a new bike, it won't all go to $hit in 2 or 3 years, If longevity is your thing, be fussy.
    • Agree Agree x 1
    • Informative Informative x 1
  8. Thanks jstava. No need to apologise for the informative post, it's the type of answer i'm looking for. Water pump leaks seam to come up a lot on a search of the FJRowners forum, perhaps coolant related. As far as this FJR goes I think I would be better off with a bike that had double the kms and serviced on schedule. The quest continues.
  9. In theory yes the coolant should be changed periodically. But just a couple of thoughts on this topic.

    Road bikes in general seem to have very few cooling system problems, and I am not sure if changing coolant frequently would reduce the number of problems.

    I have seen a blocked radiator on a Suzuki because the coolant was changed, and the new coolant reacted with the old residue. Suzuki now run a special coolant and they say it should only be topped up with this special coolant, not water, or any other coolant.

    I have seen brand new Kawasaki's leaking coolant on the showroom floor. New mechanical seals were replaced under warranty. Seen many leaking water pump seals on particular models such as Yamaha YZ/WR 250F/450F's, and coolant mostly still looked ok. I very much doubt that old coolant was the cause of all these leaks.

    So many times I have seen people make a fuss over oils, coolant, valve clearances etc, only to crash or sell the bike a few years later, without ever having any issues with the bike. So seeing this process repeated many times has made me sceptical of your concerns. The FJR is a bloody good motorcycle, and even though this particular one has sat for a few years, you may be having needless concerns. What's the worse that can happen if you buy the bike? A leaking pump? If the price is right, and there are no current issues then go for it.
    • Like Like x 1
  10. I'm hearin' you Tinkerer. The bike is a bit overpriced, considering what it's going to cost me to bring the service schedule up to date. Around $600 i'm told, for all the fluids, spark plugs and the center stand and mufflers have to come off to grease the rear shock linkage. I don't plan on buying another bike for quite some time and I need it to be as trouble free as possible so I can keep it on the road. If the price drops I may well consider buying it, it's pretty well spotless all round.