2003 Mazda 6 Radiator Replacement

[sreddos]

Does anyone know how to replace the radiator in an 03 6? Mine is cracked where the tranny fluid goes in and is leaking tranny fluid. Dealership quoted me $700 to replace so I am doing it myself. I got one on order for $135, but I am not sure of how to replace it.

Thanks

 

[sharky]

Tranny fluid in your radiator? I'm confused by your post. Are you talking about a transmission cooler?

 

[sreddos]

If you have an automatic transmission, the transmission fluid runs through the radiator to keep it cool, just like a tranny cooler, only its part of the radiator. The line for the radiator is metal, but the inlet of the radiator is plastic. It is cracked where the tranny fluid line goes into the radiator and it leaks tranny fluid when the engine is running.

 

[sharky]

Gotcha. As you can tell, I know nothing about Mazda A/Ts or the cooling system on an '03. I assume that it won't be much different than other A/T and radiator maintenance.

You'll probably just have to get in there and start unbolting things. I assume that you won't have to disassemble very much to get the radiator out.

I would disconnect the A/T fluid lines first and drain out the fluid. Then, pull the radiator drain plug and drain all of the coolant. Any oil change place will take your used fluids but they won't take them if they are mixed together.

You said that there is a broken plastic bit. Have you checked to see if you can just get the broken piece? It sounds like you might not need to replace the entire radiator. If you're thinking about it, I wouldn't suggest trying to glue the plastic bit back together.

When you get it back together, you'll have to make sure that all of the air is out of the cooling system. Fill the radiator and A/T to the recommended levels using the types of fluid your manual suggests. Then, turn the engine on and let it idle until it warms up just enough to open the thermostat. That should be the point when the temp gauge barely starts to raise. Then, turn off the engine and carefully open the radiator with a rag so that there is no chance you get sprayed. Fill it again. The level should have gone down because air was bled out of the coolant lines. Check the A/T, and take her for a spin. I'd check the levels after your first drive and again after a week or so.

My last suggestion is that, depending on the milage, this might be an excellent opportunity to change your transmission filter and replace the fluid.

Good luck.

 

[sreddos]

Well, 5 hours later, I have a new radiator. I actually had to take a lot of stuff off to get to it. Air dam, bumper, headlights, and front support. Basically you have to go down to the frame to get to the radiator. I found where it was cracked and it was the inlet nipple for the tranny line which is part of the radiator itself, so there was not a way to replace just that part. When filling the radiator with coolant, you actually don't need to put the cap on. Just fill it up and turn the engine on and squeeze the coolant lines going into the engine. It will work out the air on its own. As for the transmission fluid, I am due to have it drained, but will wait for my next oil change in 1500 miles and do it all then. Plus it will be a little warmer. Also, the Mazda 6 doesn't have a serviceable filter on the transmission.