Power steering fluid flush and power steering pump and rack replacement
Power steering fluid flush and power steering pump and rack replacement - for VW Passat
difficulty: 2/5back to 1000q: B5.5 VW Passat TDI "how to" index
This DIY shows how to flush the power steering fluid with OEM synthetic and remove the PS components. It should also work on other B5 and the Audi A4.
The steering wheel is directly connected to the steering column which operates the power steering rack. The power steering rack is assisted by hydraulic force from the power steering pump. If the rack is leaking fluid then it should be rebuilt/replaced. If you hear a high pitched metallic groaning the pump is probably low on fluid and is grinding - stop and refill it. The steering rack does not use bushings to hold it to the body. This is nice because there are no bushings to get worn out - the connection is more solid and is not harsh at all.
Only use OEM or Pentosin CHF 11s (synthetic, in the green metal can) VW / Audi hydraulic fluid in the power steering system. Pentosin CHF 7.1 is non synthetic (in the white can) so I do not suggest using it. Audi says you can mix them, BMW (also uses the same fluid) and Pentosin say you cannot but many people have mixed them with no problems. The difference is temperature rating and one is synthetic. Either will work in an emergency.
Other brands of cars use power steering fluid or ATF fluid, I do not suggest using these in your VW / Audi. In an emergency you can use them to top off the system but you must drain/flush/flush/refill it later.
If you are removing the engine, unbolt the power steering pump and set it aside. There is no need to disconnect its lines.
The power steering pumps are different in 4 cyl gas, TDI, 6 cyl, and 8 cyl. This is because of different engine rpm and mounting.
There were 2 types of steering racks used in the 4 cylinder engines (including TDI), the Koyo and ZF. They should be swappable amongst 4 cylinder because they both use 110 bar of pressure. 6 and 8 cylinder cars should have ZF racks and should not be used on 4 cylinder engine cars.
VW# g 002 000 power steering hydraulic fluid
fluid capacity: 1.0L (get 2.0 liters if you are flushing the system)
hand vacuum pump
For removing the steering rack: VW tool 1907 "centering bolt" or a bolt with a tapered head.
10mm 12 point sockets
misc extensions and torque wrench
For removing the tie rod ends
tie rod end pinch nut VW# n 102 861 10 (same as above)
tie rod end pinch bolt VW# 4d0 407 192 c
vertical tie rod end lockbolt VW# n 034 790 8
If you need more advice or details, feel free to ask your question in the 2004 2005 Passat TDI discussion forum.
Power steering fluid flush
Open the reservoir cap and use a turkey baster or hand vacuum pump like a mity-vac to suck out the old fluid. Refill and start the engine. Turn the wheel all the way to each side a few times. Suck out the old fluid, refill, and repeat.
It'll take 2.0 liters to dilute the fluid to the point where it's clean and clear. You can also do this procedure once every day to let the fluid circulate as much as possible before draining it. I do not suggest removing the reservoir lines or trying to open the fluid cooling loop in front of the radiator. This will cause a big mess and still won't drain all the fluid. The effort-benefit ratio isn't worth it.
Power steering pump removal
If there is no clearance to get it off so slide the lock carrier forward. Refer to 1000q: lock carrier set to service position for more details and pics. This procedure was done on a TDI, your car may be slightly different.
Remove the serpentine belt by putting a 19mm wrench on the tensioner's knob and moving it counterclockwise. Remove the 4x 5mm allen bolts holding the plastic coolant fan to the coolant fan clutch. See 1000q: serpentine belt for more details and pics.
Unbolt the 3x 6mm allen bolts holding the power steering pulley to the pump (shown above). Remove the pulley.
Loosen the 3x 13mm bolts holding the front of the power steering pump (yellow circles below) and the 1x 6mm allen bolt in the back (shown 2 pics below). The pump can now be set aside. Don't let it hang by the lines, rest it on a box or tie it up somewhere.
To remove the pump, remove the banjo bolts on the fluid lines. Note the washers. For pump installation, turn it over manually with fluid to prime it and prevent damage. The pump is lubricated by hydraulic steering fluid. In the pic above I replaced the pulley/bolts so that they wouldn't get lost.
banjo bolt on PS pump: 37 ft-lb
mounting bolts: 18 ft-lb
3x 6mm pulley bolts: 18 ft-lb
Steering rack removal
Start with the wheels pointing straight ahead.
Open the power steering fluid reservoir and suck as much fluid you can using a vacuum. A turkey baster or mity vac vacuum hand pump works well. Do not use your mouth.
Remove the tie rod ends (highlighted in yellow below) from the control arms. You'll probably have to remove the front wheels. If you do, make sure the car is safe and secure on jack stands at the factory jack points. Make sure the car is secure before getting under it far enough to be injured. (Ignore the disconnected upper arm, it's from another write-up).
First remove the vertical 1x 13mm bolt holding the tie rod end and squirt some PB Blaster or other penetrating lubricant into it's hole. This will penetrate down and make the tie rod much easier to remove. Then remove the 16mm horizontal nut/bolt pinching it in place. If they are rusted/seized, let the penetrating lubricant sit for a while and gently tap them with a hammer. You must remove the 16mm horizontal nut all the way because it locks the tie rod in place.
Thread the bolt back most of the way but leave a gap. Use a hammer to tap the tie rod end down and out. Once the bolt runs out of thread, use the pinch bolt, a punch, or a socket extension to knock the tie rod end out only after the pinch nut/bolt are removed. Be careful not to damage the tie rod end threads if you use a punch.
Open the driver's side door and pry off the fuse box cover at the end of the dashboard. Remove the 2x torx screws holding the side of the lower knee trim panel.
Remove 2 more torx screws in the front of the panel. There are a few spring clips that may pop out when you pull off the panel, make sure to save them. Once it's off disconnect the headlight switch, dimmer switch, and obd2 port plugs.
You can also remove the headlight switch by (in the off position) pushing the switch part forward, then turning it about 1/8 turn, then pull it straight out.
Look under the steering wheel and follow the steering column down to the steering rack. You will see a u-joint. Turn the steering wheel to get access to the 16mm nut - remove it. Then you can release the T50 torx oval shaft bolt (highlighted in yellow below) to disconnect the steering rack. Note: turn the T50 oval shaft bolt clockwise about 1/2 turn to unlock it. The oval shaft acts like a cam to lock the steering column to the rack.
Remove the plastic/foam barrier on the frame around the tie rod ends on both sides (1x 10mm nut highlighted below and a plastic plug, suspension removed for illustration).
Place a catch pan under the steering rack feed and return power steering fluid lines (19mm and 22mm banjo bolt) and let them drip dry. (This picture was taken with the engine out for illustration).
Highlighted in yellow are the lines. The white arrow points to one of the 10mm 12 point bolts holding the steering rack. You have to reach through the driver's side wheel well and around the rack using extensions and universal joints to remove it. If you can't reach it from next to the steering rack consider removing the foam/plastic shield around the axle and reaching up from there.
Remove the other 2 bolts. One is underneath the battery and the other is underneath the brake master cylinder area (white arrow below).
Remove the battery to get access to the 1x 10mm bolt underneath the battery (pictured below). See 1000q: battery removal for safety notes during battery removal. The 1x 13mm bolt holding down the tie down bracket and the cables. I suggest removing the spring clip above the battery holding the windshield trim to the metal. This will let the windshield trim move a little and make it easier to pull the battery out.
Remove the steering rack out to the side.
Steering rack installation
It's pretty much the reverse of removal but you must center the rack before installing it.
Note the washers on the banjo bolts on the steering rack.
Remove the 6mm allen bolt in the centering hole indicated belowand make sure you see the centering hole on the rack inside. Insert a tapered bolt to hold the steering rack while you install it. Install the tie rods to the correct length and then you can remove the tapered bolt.
When installing the outer tie rod ends, note the flat spot on the tie rod end. Rotate it so that it's in line with the pinch bolt (the horizontal bolt). Use a crowsfoot attachment set 90o to the torque wrench to avoid changing the torque spec too much. See 1000q: torque wrench FAQ for more details. VW's crowsfoot tie rod end tool is VW# 1923.
fluid supply line (smaller banjo bolt): 30 ft-lb
fluid return line(larger banjo bolt): 37 ft-lb
3x 10mm 12 point steering rack bolts: 48 ft-lb
tie rod: 74 ft-lb
outer tie rod vertical bolt: 5 ft-lb (it's a single use bolt so use threadlocker if you reuse it)
outer tie rod horizontal pinch bolt nut: 33 ft-lb (it's a single use nut so use threadlocker if you reuse it)