KHedges

I spent more time trying to get the right tools to get that darned banjo bolt off the rack than it would take to do this whole procedure with an actual list of what I'd need.

The PS return hose from the cooler to the rack was dripping from the end at the cooler. When I pulled the wheel, fender liner, and guard around the tie rod, it had a pinhole leak up there too. But the top end where the line bolts onto the PS rack was clean and dry, and the replacement hose clearly just clamped some 3/8" PS tubing onto a new fitting, so why not just replace only the rubber part? All I needed for that was 3 feet of 3/8" PS hose from the local parts store (about $15 at O'Reilly), two hose clamps, and a $15 compact saw that takes a Sawzall blade. The lower end of the hose is easy to access behind the bumper once the fender liner is out, and the upper end is under the tie rod. The rest of the hose goes back under the heat shield over the fender inside the engine compartment.

I think Audi used the same setup for this line on multiple models, so this isn't specific to the A6 2.8L Avant Quattro.

Tools required:
Lug wrench, 17mm socket for lugs, torque wrench (whatever you usually use to remove and replace wheels)
Floor jack and jackstands
Drip pans or cardboard
Socket wrench, 8mm, 10mm, and 13mm sockets, T25 bit, some kind of extension
Parts dish
Cutting pliers (or whatever tools you prefer to remove crimped hose clamps)
Small pry-type tool and/or screwdriver
Compact LED light (a bike headlight that wraps around the handlebars works great)
Compact metal saw (I had very good luck with the kind that's like a knife handle that takes a Sawzall blade; the blade even folds in the handle for safely carrying it in your tool box)
Shop towels
Funnel, empty disposal container for PS fluid, small clean dry jar with lid, cheap squeeze pump or large squeeze pipet
Small file and/or sandpaper suitable for deburring stainless steel and smoothing edges
Magnetic pickup tool

Parts/materials required:
3 feet of 3/8" PS hose (available in bulk at the parts store; the precut ones on the shelf are only 2 feet)
2 hose clamps, #6 or #8
Optional heat insulation wrap?
Brake cleaner or other suitable degreaser
Zip ties
PS fluid (recommend Pentosin 11S in green can) at least a pint if not a full new can

Prepare car for procedure:

1. Loosen lug nuts on left side front wheel in a diagonal pattern. (If you have an Allroad, put it in jack mode.)
2. Lift the front end up on jackstands.
3. Start the car and rotate the wheels all the way to the left. (If you want to make sure nobody tries to start the engine while the PS system is drained, close the windows and sunroof, then disconnect the battery.)
4. Remove the left front wheel, loosening lug nuts in diagonal pattern.
5. Place drip pan(s) or cardboard under left side from PS cooler to back of wheel well.
6. Unfasten about a dozen T25 fasteners (and a 10mm screw) on the fender liner and ease it out of the wheel well.
7. Get the inner shield out of your way. There's a roughly rectangular shield with an opening for the tie rod near the top of the wheel well. In the upper right corner, there's a 10mm fastener you can remove. The other two fasteners are plastic push rivet thingies behind the coil spring. Use a small pry tool or screwdriver to ease them out so you can replace them. Slide the shield down the tie rod so it's out of your way.
8. Set up waste jar under connection to PS cooler.

Disconnect hose from PS cooler:

1. Remove the hose clamp connecting the rubber low pressure line to the PS cooler.
2. Drain PS fluid into waste jar, using funnel as needed. Let the cooler and hose ends drip into the jar while you work on the other end.

Disconnect rubber hose from metal fittings near steering rack:

1. If you have the original Audi hose, it has a fancy rotating connector between the rubber and metal parts of the line that will need to be sawed off. If it's an aftermarket hose with a clamp, just remove the clamp and skip to next section.
2. Raise the suspension a few inches to get the tie rod out of your way. Your suspension is dangling down while the front end is off the ground. Just put your floor jack under the assembly behind the rotor and carefully lift a few inches so it's in a position more like having the car resting on its wheels.
3. Attach the bike headlight to the coil spring to illuminate the area under the tie rod boot. (Or prop up whatever small light you have handy so you illuminate that area.) You will see the low pressure return line with a rubber hose on the left coming out of the engine compartment and connecting to a light-colored metal line that bends up and away to the steering rack. To the right of this, you will see a double loop of black painted metal line, which is the high pressure PS line. It passes in front of the infamous banjo bolt but curves back behind the low pressure line and turns 90 degrees behind the rubber/metal junction of the low pressure line. If you don't see leakage from the connection to the rack, go ahead and replace only the rubber hose.
4. CAUTION: The high pressure PS line is less than an inch behind the area where you are sawing off the low pressure line, so you need to be very careful not to damage the high pressure line.
5. Cover the brake assembly with shop towels, as you'll be right up on it when sawing the line and you don't need to wear all the dirt from it. Cover the sheet metal at the bottom of the opening for the tie rod so you won't bang up your hands/gloves as much.
6. Carefully saw the light-colored (unpainted stainless steel) low pressure line to the right of the junction. Be patient; you will be using only 1" of saw blade at the tip and this will take a while. I'm right handed, so I rested my right elbow on the brake caliper but held the saw with both hands. Saw from the shoulders even though you're making tiny strokes because if you use the muscles in your hands/forearms, they'll get sore or crampy soon. However, the PS fluid will lubricate the blade nicely.
7. Smooth any burrs on the cut edge of the tubing with a file. (I used the flat square-ended diamond saw from the cheap Harbor Fright set because it fits nicely in the tight space.)
8. Smooth the rough file marks and sharp edges of the tubing with sandpaper. (The flexible kind is probably best, but I had some 400 grit discs left from headlight sanding that worked OK.)
9. Clean up metal filings on tubing using a magnetic pickup tool wrapped in a strip of shop towel. (It's a magnetic Q-tip.)

Remove old rubber PS hose:

1. Follow old rubber PS hose up to heat shield.
2. Unscrew 13mm screw/bolt holding heat shield in place. The coolant lines will be in your way, so use extensions on your socket wrench as needed.
3. Release tiedowns near firewall and heat shield.
4. Remove waste PS fluid jar and put a lid on it.
5. Pull hose through rigid guide where it turns to go down to cooler.

Install new rubber PS hose at PS cooler:

1. Protect ends of new hose with a piece of shop towel or plastic so you won't get grease or dripping PS fluid in the part to be clamped.
2. Lay hose down where you just removed the old hose, but don't install any tiedowns yet.
3. Thread the hose down the guide and pull the end down to the PS cooler.
4. Degrease the barbed fitting on the PS cooler.
5. Hang one of the hose clamps on the PS cooler, oriented so the screw will be easy to tighten.
6. Remove the cover from the end of the hose.
7. Slide the end of the hose over the barbed fitting.
8. Tighten the hose clamp near the end of the hose.

Install new rubber PS hose on metal tubing near steering rack:

1. Hang the other hose clamp on the hose coming in from the engine compartment with the screw easy to access.
2. Degrease the cut end of the metal tubing (it will still be dripping PS fluid).
3. Remove cover from hose.
4. Slide the end of the hose onto the tubing and up to the bend.
5. Tighten the hose clamp, making sure the free end doesn't get caught on the tie rod boot. If needed, curve the free end around the hose so the tie rod boot won't be damaged when you lower the jack under the suspension. (I used #8 clamps which had too much free end sticking out.)
6. If you want to add heat insulation around the rubber hose, this is a good time to do it.
7. Replace tie wraps and heat shield. (If the original ones broke, use zip ties.)

Refill power steering fluid and purge air from system:

1. Clean cap to PS fluid reservoir.
2. Unscrew cap and set aside on a shop towel.
3. Pour PS fluid into reservoir, overfilling but not a lot over the HOT line on the dipstick.
4. If you add too much, remove some with the squeeze pump and set aside in a clean covered jar. (If you have any crud in the system, don't contaminate the fresh can with it!)
5. Check dipstick; if you removed too much, add some with the squeeze pump from the jar.
6. Replace cap.
7. Reconnect battery if you disconnected it earlier.
8. Start engine and turn wheel back and forth to both stops 5 times. (This will be noisy as air purges out!)
9. Check PS fluid level (it will be bubbly) and add more again.
10. Check both ends of new hose for leaks and tighten if necessary.
11. Repeat purge cycle at least once. It should get quieter.
12. Make sure upper hose connection isn't leaking before you reinstall shields and wheel.

Reinstall shields and wheel:

1. Remove light from coil spring area.
2. Replace small inner shield, starting with plastic push fasteners on left side.
3. Replace fender liner.
4. Using floor jack, remove jackstand on right side. (It's easier to replace the wheel on the left side if that side of the car is facing upwards a few degrees.)
5. Replace wheel (tighten lug nuts in stages diagonally, final torque to 90 ft-lb).
6. Using floor jack, remove jackstand on left side.

Complete air purge:.

1. Check PS fluid level and add some if needed, but not to top mark on the dipstick; replace cap. (If the fluid in the reservoir still seems to have bubbles rising, take a break.)
2. Start engine, turn wheel to stops 5 times each side. It should sound and feel normal by now.
3. Repeat steps 1 & 2.
4. Check PS fluid level, which shouldn't be dropping by now. If it's the same, and the steering sounds and feels fine, purging is complete.
5. Remove excess PS fluid with squeeze pump or top up as needed.

Aftercare:

1. Pack up your leftover PS fluid, squeeze pump, and funnel to keep in the car, in case a hose comes loose or you need to top up.
2. Put cardboard under the cooler connection in your parking spot to check for leaks before you leave.
3. Check the PS fluid level frequently in case of leaks at the top end or just more air working its way out of the system.

KHedges

n/t

Stubborn, but Happy

How is your work holding up so far?

I’m staring down the barrel of finding my own solution to the same issue in a 2001 allroad. Yours makes perfect sense. Does it hold up?

KHedges

Thanks for asking! I check it any time I have the wheel off and it's 100% leak-free so far.

Stubborn, but Happy

Thanks for letting me know. I have an OEM return line in my hands, but from what I’ve read elsewhere, I really don’t want to try to install it in its entirety. In all fairness, I haven’t taken the wheel liner and tie rod cover off to peer inside yet, and that’s when I’ll decide, but your solution sounds very tempting.

I’ll let you know the outcome.

KHedges

I didn't see your photo when I answered on my phone. Gorgeous travel shot with your Allroad! I have heard so much about what fun cars they are for trips like that. There are times I wish I had an Allroad instead of my "lowrider" Avant Quattro. Such as when I see an interesting side road or my front bumper hangs up on a curb AGAIN. (I was going to replace the bumper this week, then we had a heat wave followed by wildfire smoke.)

All you need to remove to access the rubber/metal junction is the wheel and fender liner. Just turn the wheels hard left to angle the tie rod out of the way. After I wasted a couple of days on tool runs without a spare car when I was still trying to access the banjo bolt, the procedure I wrote up took only an evening. It takes patience to saw through the stainless steel line because there's so little room for each stroke, but as repairs go on these cars, it's relatively easy. You can see what you're doing, there's room for your hand, you're not trying to insert tiny little parts with a magnet (hello valve stem keepers, all 60 of you little buggers), and you're not expected to torque something in a space where no torque wrench would fit.

I don't think I gave credit to another friend I consulted about this. I originally thought of using a Dremel, but he advised against this because there's so much important stuff going through here (brake lines, high pressure power steering) that you could wreck if the rotary cutting wheel slips. You also want to minimize and clean up any metal particles. Re-reading my procedure reminded me why I have oily shop towel on the end of my magnet.

Stubborn, but Happy

And thanks for the appreciation of road trip photos—that one was a great one. The day of the photo started before dawn up the long climb to 10,000’ in the White Mountains, where I photographed Bristlecone Pines from sunrise until noon. Of note to Audi drivers, Highway 168 out of Big Pine to the turnoff for the Bristlecones is one of the most amazing pieces of asphalt I’ve ever driven. Surreal and entertaining enough to keep one laughing the whole way.

Anyway, I held off on replying because of the journey that continued to unfold around the return hose. I won’t bore you with the whole process.

When I finally got the tie rod surround off the wheel well and peered in, the first impression was honestly, “Wow, that doesn’t look too bad.” I knew I was in trouble then... But the ensuing investigation and being shown how it needed to happen just kept coming to me. At one point, I was certain I was going to do it the way you had described. But the very next morning I found myself ordering a very expensive German offset box wrench (20/22mm) from KC Tools—fully commited, without any conscious decision, to replace the entire hose.

The tool arrived, and the next day was pretty amazing. I hadn’t noticed that all this time I had been doing alot of proprioceptive practice in my head. It all went smooth and steady. All I removed was the wheel well liner, detached the end of the tie rod, and got the hose out relatively easily. Getting the new hose threaded down from the rack to the cooler went well, and I attached it there. Before I got to the upper end, several scenarios for dealing with the new washers and getting the banjo bolt threaded came through, and I settled on what seemed most plausible: mainly, getting the bolt and first washer in and up under the pressure pipe into the end of the return hose with my right hand, then, with my left hand and a long forceps holding the top washer, slipping that washer over the end of the bolt held up through the return hose. So I went in with the right hand, and actually got it in place right away. Now let’s see if I can really get this washer in there with the forceps in my left hand. I dropped it the first time I released it from the forceps, but pulled it back out, and thought, gee, it almost feels like I can get this in there with my hand. After deciding to abandon the forceps, the whole procedure was done with eyes closed and everything transpiring on the inner. Tried it, and got it the first time. The real kicker then came when I kept going and went for threading the bolt—and got it on the first try!!!! I was so amazed I wanted to scream inside. But I chose satisfied containment instead, which only got me higher.

I had anticipated spending the better part of two days on repeated attempts to accomplish this! And it turned out to be an immensely gratifying slam dunk. Holy Moly. I receive a lot of help on the inner, but this was a whole new level. Would that all Audi inner expeditions be so graced!

Thanks for your encouragement, and inspiration. I really thought your approach was what I was going to do. But then, I’m usually the last to know!

That was two days ago—everything remains dry as a bone.

KHedges

I'm glad you got the right and proper replacement to work for you. That's very impressive fine motor control work!

Stubborn, but Happy

In truth, the procedure transpired through sensory currents, rather than motor—and “I” was not the do-er. But that’s an entirely different story.

If you and your Avant ever find yourselves in the lower end of the Owens Valley, by all means take the time for that road east out of Big Pine. It’s unbelievable. On the way down, I was almost catching air. But the turns are a little too tight to do that—for me anyway.