Am getting ready to do a coolant change on my st170 2003.

I know this is an easy job, but i just want some advise on do's and dont's, last thing i want is a cracked head, or air in the system,

can sombody give me a guide, also, im not going to bother with rad flush, and im using the blue anti freeze

 

1.Pull bottom hose off rad
2.undo top hose to engine.
3.unscrew the cap on expansion bottle
4.blow down top hose until all coolant has come out of bottom of rad.
5.put all hoses back on.
6.start engine and fill with coolant/water..50/50 mix.leave cap off for now.
7.inside the car turn heater on hot full power.
8.whilst checking the coolant level in expansion bottle,rev engine at about 3000rpm until you get constant hot air from blower.
9.then switch off blower and check coolant level,top up to max if low and put cap on.
10.all this time engine is still running.now rev engine again at 3000rpm until you hear the fans cutting in.
11.then idle until you hear fans stop and rev again till fans cut in for a second time.
12.switch off engine and let it cool down(10 minutes)
13.finally top up coolant to max and your done.
As you have already checked that you have warm air in the car ,you will not have an air lock.
Good luck ..

 

fantastic guide mate, thanks a lot

 

but that won't remove anything from the block

 

If you pull bottom hose off rad as stated in item 1,the coolant from the block will come out

 

not personally worked on one, but 9/10 cars it won't as the thermostat creates an airlock so the water won't drain out the block.

 

I've never had a problem using this method,obviously you won't get rid of all the old coolant but the majority of it you can.