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Model specific boards => Golf mk3 => Topic started by: WeekendMechanic on 06 October 2012, 19:18

Title: Coolant change and Brake fluid
Post by: WeekendMechanic on 06 October 2012, 19:18
I am currently doing all service interval codes,and I am on coolant change which needs to be done every 2 years,but on the haynes manual it says you have to drain the coolant from the thermostat hole,which means I have to take off the auxiliary belt and power steering pump to get to,is this true,do I have to do all this work to do it properly?
Title: Re: Coolant change
Post by: itavaltalainen on 06 October 2012, 23:54
Well.... you could just the bottom rad hose off. This way you'll drain most of the coolant, but not all that's left in the engine.
Taking the thermostat housing off will also drain that last bit.

Personally speaking, taking PS pump off the block (leaving tubing connected!) is not the biggest job. Only a few bolts and the p/s belt - then you can get to the second bolt for the th. housing and remove it. This is the sh!t part cos you'll end up with coolant in your face ;)

Then would drain it all this way - and only put the thermostat housing back on and keep the p/s belt off - and the pump well clear of engine. Top expension tank up with pure water and then fill up fully and run engine to flush the system. After that's complete (and cooled down again) re-drain and then fill with 50/50 water and G12++ coolant. This then would allow your 5 yrs drain intervals.

This was the 100% way.
Then obviously you could just opt not to take P/S pump off and "rinse" with pure water after draining by just taking bottom hose off and then drain again after rinse cycle (after thermostat has been opened for few mins) from the radiator bottom hose.

Then after draining the water again, fill up with a bit more coolant concentrate (i.e. 40% water, 60% concentrate) for the new fill and that would be pretty much the same ;)

I'll leave the decision up to you.

Only thing I'd recommend is to use "red" G12++ coolant since that can stay in the engine 5 yrs.
 
Title: Re: Coolant change
Post by: CJA321 on 07 October 2012, 00:08
Just take off the bottom hose. Its a piece of piss. Or if your lazy and of most dealers do in honest reality. Drain the coolant bottle only and refill that with pure coolant. Or test the strength of it and make sure it actually needs changed. If its weak adjust it to requirements
Title: Re: Coolant change
Post by: itavaltalainen on 07 October 2012, 00:19
Antifreeze does not loose effectiveness after 100 years but the anti corrosive and lubrication additives will deteriorate, hence replacing is needed every once in a while since those cannot be readily tested by "measuring" freezing temp. This will make sure that your water pump gets lubricated and your cylinder head and gasket don't happily corrode away.....

Only cos dealers don't do it properly doesn't mean it's OK or good practice (in particular if the only reason they do it that way is to safe time). Best example VW also recommends long-life servicing but personally I would not leave oil in my engine 20k miles / 2 years.
Even in an old Mk3...
Title: Re: Coolant change
Post by: CJA321 on 07 October 2012, 01:09
By the time you change the belt you will do a waterpump at the same time anyway, so do the antifreeze at the same time obviously. I know this might not necisarly be the same on the 8v as it runs off the aux belt but you know what i mean.

As for long life, i dont fully get it. I wouldnt leave oil that long either.
Title: Re: Coolant change
Post by: WeekendMechanic on 07 October 2012, 09:24
By the time you change the belt you will do a waterpump at the same time anyway, so do the antifreeze at the same time obviously. I know this might not necisarly be the same on the 8v as it runs off the aux belt but you know what i mean.

As for long life, i dont fully get it. I wouldnt leave oil that long either.

Yes that`s what I was thinking I will do the coolant after I change the timing belt

What brake fluid do I use DOT2, DOT3, DOT4, or DOT5 on a golf mk3 also my brake lines are really dirty I heard you can flush them with alcohol but what type thanks.