This is in regards to the two coolant leak threads. https://www.feoa.net/modules.php?name=Forums&file=viewtopic&t=47158 https://www.feoa.net/modules.php?name=Forums&file=viewtopic&t=46367 The hose in this pic is the hose that is offen the cause of an unknown coolant leak. This is the tutorial to change that hard to get to hose on the back of the block that circulates coolant from one side of the block to the other. The part is obsolete and after days of calls to parts store, dealers, and hose shops I still couldn't find the right part to replace the leaking hose. ------ PARTS YOU WILL NEED: NEW HOSE (1") and unbent, it needs to be about 25" ONE GALLON OF ANTIFREEZE HALF A QUART OF MOTOR OIL NEW HOSE CLAMPS (SCREW ON TYPE) trust me, you want to get rid of the spring loaded ones. I almost lost an eye trying to put the old ones on the new hose. ------ The very first thing you will need to do is make sure you car is cool and to drain the radiator via the flush spout on the bottom of the radiator on the driver's side. Of course, you will need a new hose. After searching and searching, the best suggestion I received was to use a hose that looks kind of like the one that needs to be replaced. No not Mazda, because that part is obsolete too. The part I got from Kragen was a standard bent Goodyear bypass hose. On line it's 12 bucks. At the store it's 15. Part number 63925. There is a sharp bend in the OEM hose so you will need one that has a bend in it. The next picture indicates what you want the hose to do when it is connected. The red mark will be the shape of the hose when it is in place. The first thing you will want to do is remove the air intake hose. This will allow you to get to the top of the hose so you can remove it without issues. Once you have the air intake off, you will be able to see a lot of wiring and other hoses. The one I am replacing lies beneath the green temp sensor and heads toward the back of the block. (not the heater hose that goes into the firewall) I have marked the right hose with a red dot. You will need to get a pair of pliers to take the clamp off. On mine, I could not slide it further down the hose because the hose had swelled to large to move the clamp. I ended up cutting the hose off with a knife and then cutting the small piece that was left off. When you get it off, you will see some corrosion. If it's bad, look for cracks and take a wire brush to it to clean it up some. Now that you have that off, lift the car and place it on jack stands. When you get under the car, look for the hose just above the oil filter. It is not the hose with the slotted hose protector on it. I have indicated the correct hose with a red dot in the following picture. You will need to remove the oil filter to get to the hose clamp so prepare for that. You will loose a half a quart of oil at most so have some on hand. This section of hose didn't give me any issue coming off but be prepared to get coolant down your arm and in your shirt because it will come out. Once disconnected you can pull it out from either the top of bottom of the engine. This is the hose that I am replacing. As you can see, the two ends have been cut off. Now it's time to put the new hose on. I suggest starting at the bottom. You will want to cut off about an inch and a half of the hose on the bent end. This end will be going under the vehicle. Put it on and cut it to your specs. Remember, the new hose will not be snaking between the fuel injection and the block. It will be bypassing it completely and heading toward the firewall so give room to go around the stuff. The new hose is in place with the new hose clamp. Remember to give enough room for the clamp so that the oil filter can go back in. I am going to say this now so that you won't make the same mistake I did. Tighten the clamp with a wrench, not just a screw driver. Tighten it till it won't tighten anymore or it WILL leak I left about an 8th of an inch from the base of the male end to get a good connection. Place the oil filter back in place an tighten to spec. Make sure that the new hose isn't rubbing against anything (it won't). Get up from under the car. Pull the new hose up and place it in the male end of the upper end to get an idea of where you will need to cut it. Remember that you need some extra length so that the hose makes a gradual bend and will not kink. You have lots of room and lots of hose to do this so take your time. Make sure you tighten the new hose clamp with a wrench or it WILL leak a lot! After you have it on, also make sure that the bend in the hose is gradual and not sharp so that you get no kinks. Once it is secured replace the air intake hose and vacuum line. Make sure the flush plug on the bottom of the radiator you opened to drain is closed and refill the radiator with water. Make sure you check the oil level and add as needed before you start the car. Once full, look for leaks. If you have compressed air, blow off the area with air and look for water flow. If all is good then start the vehicle and let it run. Look for leaks right away and let it run for at least ten minutes. If you have no leaks then you did it right. Let the engine cool and empty the radiator the same way you did at the beginning. Refill with 50/50 coolant and lower the vehicle. You're done!