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Audi A4 (B5). Power Steering Cooler Install


In my seemingly neverending quest to prep this pig for the track this season, I finished one of my main concerns tonight. Last year, at Carolina Motorsports Park in Kershaw, SC (a 2.3 mile, 14 turn course thats hell on the car), my power steering fluid boiled, seized the pump, sending bits of pump into the rack. $2000 later, I realized I can't be at 5500rpm all day long without some kind of temperature reduction for the whole system.

After installing the EVO FMIC this weekend, the factory PS cooler (just a small aluminum tube attached to the bottom of the radiator) had to be relocated to the side, hindering airflow around it. You couldn't touch the factory cooler after a short drive without sizzling your flesh on it.

I went to Auto Zone today (open on Easter!) and picked up the Hayden 401 model transmission cooler:



It cost $26.99 and was the smallest cooler that they had in stock. It came with all the necessary clamps and mounting devices, and a 4' double walled high pressure hose. I cut the hose in half and it reached where I needed just fine for both inlet and outlet.

First step is to remove the factory cooler... unbolt it and remove the small hose clamps from the reservoir hoses. Have a pan underneath these hoses as about 1qt of fluid will drain out. Fish it through the labyrinth of hoses and pipes and bring it out the bottom. This is easier to do with the bumper off, but its no biggie if you remove the side grills.

In order to use the hoses that came with the kit, you must cut the ends off of the factory cooler. I left about 2.5" so it could give the hoses a little support at the bottom:



The ends of the pipe were ground down as to be smooth and round, with no sharp edges. I then used a flare tool to give a little lip so the hose would stay secured. The pipes were cleaned and washed out with carb cleaner, and blown through until dry and clean with my compressor. You don't want ANY dirt or shavings getting into the system.

Get everything secured tightly with the supplied clamps, and find a good position for the cooler. When the hoses are routed cleanly, with no kinks or rubbing on anything, go ahead and mount the cooler with the supplied cinch straps. It's a real bitch snugging those up and trimming the strap from behind-- as shown in my pics, so use the straps so the excess comes out the front to save you some time.



Make sure nothing is rubbing, and refill the PS reservoir with Pentosin. It took an extra .25L or so to make up for the extra volume in the cooler. Start the car, and let it idle for 30 seconds or so to build up pressure in the system. Check for leaks, and start bleeding it.



With the front of the car off the ground, and the cap off the reservoir, turn the wheel from lock to lock repeatedly, varying engine speed from idle to ~2000rpm. Add fluid as necessary, and when the air bubbles disappear from the reservoir, and the groaning noise from the pump goes away, you're done. Go for a drive, and make one final check for leaks, then reinstall the belly pan.

I can now drive the car and put my hand on the lines and they are only warm to the touch. Total cost = $45 including a liter of Pentosin. Took about an hour from start to finish, and now I will feel much more confident feeding in opposite lock at redline when I'm thrashing the car out on the track :)

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