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mazda-fla 06-25-2012 12:14 PM

Complete Guide to changing all coolant hoses on 2.3 with pictures
I changed each and every single coolant hose on the 2.3. So I put together this guide.

Parts List:

Required parts:
Lower Radiator Hose: KJ01-15-185 (also available aftermarket as "cut to fit")
Upper Radiator Hose: KJ01-15-186 (also available aftermarket as "exact fit")
By Pass Hose: KJ01-15-261 (also available aftermarket as "cut to fit")
Sub Tank Hose (to Thermostat): KJ02-15-381A
Sub Tank Hose (to Radiator): KL47-15-383A
Oil Cooler Hose (in): KL47-15-536A
Oil Cooler Hose (out): KJ01-15-546
Thottle Body Hose: KJ01-13-682A
IAC to Thottle Body Hose: KJ01-13-681
EGR Hose: KJ01-13-691
EGR Hose: KJ01-13-692
EGR Hose: KJ01-13-693
Heater Hose and Connector: TA16-61-24XA (also available aftermarket as "exact fit")
Heater Hose and Connector: TA16-61-24YB (also vailable aftermarket as "exact fit")

Optional parts:
IAC Air Hose: KJ01-13-766 (Note: this is not a coolant hose, it is an air hose that I replace because mine was trashed)
Throttle Body Gasket: KJ01-13-655 (Optional if you are removing throttle body)
Thermostat: KL-15-171A (also avaliable aftermarket - buy one as "exact fit" with gasket and giggle pin)

Optional materials and supplies:

Spray can of Copper Gasket Maker spray, in case you have decades old metal gaskets and you want to freshen them up.
Assorted pack of colored electrical tape or colored zip ties for marking purposes.
One gallon of antifreeze and one gallon of distilled water, or two gallons of pre-mix. Might as well fill it up with new antifreeze while you are at this.

Special Tools list:
Most tools are just standard stuff. The usual 10 mm and 12 mm socket and extensions. Pliers and needle nose pliers. The only thing special is you need a couple long pairs of needle nose pliers. I used a pair of 12 inch needle noses and 18 inch needle noses. You won't be able to get a few of the hoses with standard needle noses, so you need a couple of long pairs. You also need a 25 mm open end wrench to remove the big nut on the EGR.

Total Time from start to finish: 10 hours. I did this all in a single day, but it took the entire day with two short breaks and a short lunch break. But pretty much 10 hours non-stop labor. Nothing to terribly complicated. Just a lot of stuff to remove and reassemble. The kind of thing that it is an hour of labor to get to the point to do a 5 minute hose change.

mazda-fla 06-25-2012 12:17 PM

Prerequisite steps:

These steps are just to start getting things out of the way to do the work.

Drain Coolant. By removing the drain plug. This will drain about a gallon of antifreeze. Later on when you remove the oil cooler hose, that will drain about another 1/2 gallon of antifreeze.

Remove Cover:

Remove cover that says "Miller Cycle Engine".

mazda-fla 06-25-2012 12:19 PM

Remove intake for rear intercooler:

mazda-fla 06-25-2012 12:20 PM

mazda-fla 06-25-2012 12:26 PM

Throttle Body hoses and IAC to Throttle Body hose.

To change the throttle body hoses, you have to strip everything down to the throttle body.

Remove top of air filter box:

mazda-fla 06-25-2012 12:29 PM

Remove Resonator Box:

Make sure you mark all the air hoses that connects to the resonator box, so you can remember how it all goes together. I used different colored electrical tape. They make colored electrical tape, and also colored zip ties. You could also get masking tape and mark it, or a label maker. Whatever you have is fine, just make sure you mark everything or will regret that you didn't when you forget where everything goes. Also, be careful removing the air hoses from the plastic nipples on the resonator. Use a gentle twisting motion. You don't want to break the plastic nipples, because the resonator is a couple hundred dollars if you break the nipples on it.

mazda-fla 06-25-2012 12:31 PM

Remove the bottom of the air filter box:

You need to remove this because later on you will need it removed to better access the lower radiator hose. So might as well do it now.

mazda-fla 06-25-2012 12:32 PM

Remove Rear Intercooler:

You will need to remove this to get better access to one of the hose clamps on the throttle body.

mazda-fla 06-25-2012 12:38 PM

Remove IAC to Throttle Body Air Hose, and Coolant Hose:

OE Part Numbers:
IAC to Thottle Body Hose: KJ01-13-681
(Optional, if yours is bad) IAC Air Hose: KJ01-13-766

My IAC to Throttle Body coolant hose was leaking. You can see the crude on the nipple and the dripping crust below. Also, I wanted to pull my Throttle Body off for cleaning. In order to do that you have to remove the IAC to Throttle Body Air Hose. Mine was cracking and dry, so removing it I knew would destroy it. So I bought a new one to have on hand, and had to use it because I had to cut that air hose off. I also bought a new IAC gasket (o-ring), because I was originally going to remove it and clean it. But since my IAC is fine, and there is really no place to accumulate carbon, and the fact that the IAC is over $400 to replace. I figured "if it ain't broke, don't fix it". I left it alone. I didn't want to remove it and risk messing it up, especially since it is working perfectly as-is.

The first picture is before the change and cutting everything off. The second picture is the new hoses installed after everything was removed and replaced.

mazda-fla 06-25-2012 12:40 PM

Optional. While you are there, you might as well remove and clean the Throttle Body:

Here it is, both front and back side, nice and clean.

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