Monday, October 26, 2015

Transmission Cooler Line Leak Fix.

Disclaimer: Transmissions are EXPENSIVE and depending on the make, year and model can be VERY difficult to remove and replace if a line comes apart under pressure and destroys same. Any hydraulic line should be considered under very high pressure and so much so as to inject fluid under your skin. The pieces are very sharp and can cause some nasty injuries to skin and eyes. Injuries due to slips and falls can happen do to fluid that is not in a container. Property damage can also occur including to pavement, your vehicle, clothing or other property. Wear personal protection equipment such as eye and hand protection when working on a vehicle. I have no control over the quality of your work, the condition of your vehicle, or the situation of your work environment. When in doubt over the quality of material, your competence or state of sobriety, use OEM parts and/or consult a competent automotive professional to perform the work. Perform any and all repairs at your our risk. This is for informational purposes ONLY!

Back in the day, I could re-plumb transmission lines on the family Oldsmobile in about ten or fifteen minutes with a hoist, wrench, a set of steel lines and my mitts to bend them to shape. Today, cars and trucks are using hybrid lines made of steel, with rubber hoses at the vibration points with crimped aluminum fittings at each end. What's more is that the steel ends are usually quick connected into the radiator and held into the transmission with a flange. In time, the steel part of these lines will rust out and develop a leak, meaning replacing the entire line with an OEM or fabricated part from a steel line and a flaring tool. This is the proper way to do it and will last the longest, but the problem is that most of us drive an old car or truck already. These lines are expensive for the OEM ones and a bit time consuming for the ones you fabricate. Especially if you want to do a professional job. Again, if the steel part is leaking, this is the only way to go.

However, the rubber hoses are usually the culprit, especially on the pressure line. They deteriorate with heat, age and pressure until they shrink inside of their crimped ends and form a leak. This is usually apparent by transmission fluid wetting the outside of these parts. The first thought would be to replace the entire part and that answer should be a resounding "yes"! Even so, there are times that the part is either not available from the neighborhood auto parts store, is too expensive or one or both of the ends is going to be too difficult to get at. While this should be a non issue with the proper equipment, there are instances that we don't have time to fight with these parts. As forbidding as this job looks, you should be able to do this with a minimum of tools, materials, time and money. You'll need, a funnel, a cutting wheel, or a drill motor with a 1/4" or 7mm bit, as well as side cutters, a set of pliers, a small tubing cutter, a utility knife or other material to cut the new hose. For materials, you will need transmission cooler hose that fits very snugly over the steel line (this is where a competent auto parts person helps, because if the lines slips off easily, IT WILL LEAK), a pair or two of fuel injection hose clamps to fit over those lines snugly (these differ from the heater hose clamps in that the bands are solid and a screw and nut cinch the clamp around the rubber line {heater hose clamps will NOT work}), and a quart or two of your favorite transmission fluid. You might also want a catch pan and rags to clean up spills.

Remove the aluminum crimps over the line with either a tubing cutter on the OUTER layer (Do NOT cut off on the steel line), by cutting lengthwise with a cutting wheel, or carefully drilling a series of holes so you can peel the crimp off the rubber line . Again, do NOT damage the steel line. Then you can remove the rubber hose and a new piece to fit. Install a clamp over where the serrations are on the steel line over the rubber and tighten securely. Carefully fill the transmission with enough fluid to replace what you lost, but do not overfill. Start your vehicle and check for leaks, tightening the clamps and wiping any fluid off the outside of the lines. For the next few days, make a habit of checking these for leaks and as long as they stay dry, mission accomplished. Maranatha!


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