anyone have any tips for coolant flush, my mechanic recommends I bring it into Mazda dealer to have done, possible issues with bubbles forming according to him. Is this right?

 

Hi, main tips are...
Make sure you replace the radiator plastic drain plug and washer (these become brittle with age), and don't over tighten it,

If you have an FL22 sticker on your radiator cap, then its long life coolant and only needs to be replaced every 10 years,

Jack up the front of your car until your front wheels are approx 6 inch off the floor (this will bleed the heater system of trapped air),

Put your heater on hot and fan speed on 2,

Fill your radiator with the correct coolant until the level stops dropping,

Leave the radiator cap off, start your engine and allow the engine to warm up, topping the coolant up as required,

After approx 5 mins your heater should be blowing warm, if not, turn to cold and then back to warm.

When heater is blowing warm, switch off heater fan, and monitor the coolant level,

The coolant level will rise and fall several times during warm up stage, make sure you keep the level topped up,

Once all the air is out of the cooling system, the engine should be hot, the temp gauge should read half way to 3 quarters and the radiator cooling fan should operate.

Then carefully refit the radiator cap and lower the car back onto the floor,

Add coolant to the expansion bottle, and add more than the maximum mark to allow for the level to drop when the engine cools,

Points to remember are... Heater should be hot, radiator fan works, correct coolant level and no leaks.
Recheck coolant level mark in expansion bottle when engine is cold.

ALWAYS REMEMBER... COOLANT CAN BURN!! Be careful.

Hope this helps!