Anti-freeze mud - Lee H
I posted a thread a while back about checking my anti-freeze, and after having to sort out a puncture today at tyre centre, they checked the water with that syringe thing I was advised on.

I'm fine for -50 or something ridiculous, but the water was a decidedly murky brown colour....I think that's probably not too healthy.

Should I do something about it? - it's a 1.6 Xantia, doom blue, but much loved.

Re: Anti-freeze mud - David W

Treat the poor old car to some new coolant this weekend, you know it makes sense.

Re: Anti-freeze mud - Lee H
OK, you've got me convinced (and afm, head gasket failure? oh dear, I don't like the sound of that)

How do I do it.. Will Halfords rip me off if I turn up there for just a coolant change? Where else can I go and how much should I expect to pay?

I'm a bit of dead loss under the bonnet (although I do know how to check the oil, water, etc) Would I be pushing my luck to try and change it myself?

Re: Anti-freeze mud - ladas are cool
i would get the haynes manual and do the job myself, its not hard to do the job, and you get a kind of buzz knowing that you did the job yourself.
Re: Anti-freeze mud - afm
They test the water with a hygrometer to estimate the % anti-freeze concentration and degC freeze protection. However, the ethylene & propylene glycols in the antifreeze will eventually oxidise into acidic compounds when hot; apologies to the chemists, I'm a bit vague on the formulae.

Although the antifreeze protection may be adequate, the corosion inhibitors need to be renewed, by replacing the solution every 2 years or so. Corrosion and head gasket failure are fairly certain if the inhibitors are exhausted.

I had a service done at Halfords; the service sheet said to test anti-freeze concentration and corrosion inhibitors so, out of curiosity, I asked how they tested the inhibitors. The man hadn't any idea what I was on about, so I shut up.
Re: Anti-freeze mud - Stuart B
Sorry afm I know nobody loves a smart alec but I have engaged pedant mode.

A hygrometer is what is used to check for moisture content in the atmosphere.

The device for checking the relative density of a fluid is a hydrometer, used for such tasks as antifreeze content, battery acid strength and in beer brewing.

Re: Anti-freeze mud - robert

I had my Omega serviced last week and asked that the coolant be changed. Before it went in it the coolant in the header tank was a yucky brown colour. It came back from the service all nice bright blue, smelling really sweet and without any scummy bits in the header tank as it had been flushed as well.

This was the first coolant change in 60,000 miles and 3 and a half years from new.

Go on - treat yourself ......

Re: Anti-freeze mud - Brian
Once upon a time, radiators had drain plugs, not any more, so you will probably have to remove a bottom hose to drain the system.

When refilling it is easy on modern systems to get an air lock because of the complicated hose arrangemets, so you need to locate ALL the bleed valves and make sure water comes out of them. I have a suspicion that even garages or service centres may neglect this on occasions.
Bleeding. - David W

Brian is right about bleeding, this is crucial. I have no idea about others and how they charge for this but I usually do it for under £30.

If you want more info to "DIY" e-mail me.

Re: Bleeding. - Alwyn
Had a water pump changed on a Sierra a few years ago. I drove it about half a mile and heard severe banging from the engine.

Limped back to garage and they found that there was an air lock in the cooling system. Ooops.
Re: Bleeding. - Andrew Hamilton
I check the coolant in the freezer which is usually at -25degC just for confirmation that it is still liquid!

Value my car