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Discussion Starter #1 (Edited)
WARNING:
I'M NOT RESPONSIBLE IF YOU DON'T TAKE THE NECESSARY PRECAUTIONS TO PROTECT YOURSELF. PLEASE VERIFY THE PARTS THAT YOU CHOSE TO PURCHASE TO DO THIS MOD AND MAKE SURE ALL THE PARTS ARE RATED FOR THE HIGH PRESSURE, IF YOU CHEAP OUT YOU MAY CAUSE A FIRE AND OR WORSE!!

Subaru power steering systems are finicky on the turbos models. I've found 12 points of failure in the system and this mod will reduce it to 4. The stock system came with spring clamps which get weak over time. This can allow air into the system which will cause "rough" spots in the steering, whining noises and eventually loss of power. The weaker those get, the more it may lead to leaks as well. (power steering fluid will ignite if it touches a hot turbo!!!)

Another HUGE issue is that being attached to the block AND being very close to the turbo, these lines get very hot which will wear out your pump faster and boil your fluid, which really sucks for autox.

Anyways for my build I decided that I wanted to build a setup that moves the line away from the turbo, doesn't touch the motor and is slightly longer to add more volume and cooling.

My application is a 98 RS with a 04 STI swap. I routed the lines down along the cross member and along the frame rails to the passenger side of the vehicle.

The STI pump operates at around 1200 PSI which is not a joke. You _MUST_ use a hose which is rated for that amount of pressure. Standard stainless hose will not cut it. I chose PTFE which is a hard teflon inner hose which is resistant to heat, corrosion and pressure. I used Fragola brand premade hose to save time and per their website: the -6AN is rated at 2500 psi working pressure and 10,000 burst. I recommend using steel but had to use aluminum for the adapters. The return line is low pressure, but the spring clamps should be replaced with worm drive clamps or better t-bolt clamps.

1. Using a turkey baster or some method of suction, remove the power steering fluid the best you can. I got a vaccum pump gun with a fluid reservior from harbor freight for 15 bucks and got some clear vinyl hose and that made short work of it. Once you get most of it out, undo the clamps and remove the reservoir, then suction down both hoses the best you can.

2. Remove the accessory belt cover, the banjo bolt from the top of the power steering pump, and you don't have to but I removed the spacer below where the banjo bolt is threaded.


Also undo the clamp for the return line. Since you're draining the power steering, this may be a good time to replace the O-ring on the return line which leaves you prone to drawing in air. You unbolt the return line tube and the o-ring is underneath: 34439AE020 (under 2 bucks)

3. Remove the airbox and hose to gain some room.

4. Unbolt the power steering hose from the passenger side of the block.

5. The hardest part of this mod is getting the lines off of the rack. If you're doing a swap, while the motor is out is the best time to do this, when is when I did it. If you have already done the swap, you could try unbolting the motor mounts and using a cherry picker to lift the motor up to give you some clearance. The nut that's on the rack side is the stationary one, so make sure to loosen the hose side so you don't bend the tube. Be warned that you will get some power steering fluid on you, the level depends on how much you got out!

6. From there I assembled the hoses in this order from power steering pump to rack, making sure that all the adapters were tight:

High pressure line:

14x1.5mm o-ring male to -6AN male adapter

Fragola Performance Systems 460614 - Fragola Performance Systems AN to Metric Adapter Fittings - Overview - SummitRacing.com

*** lots of people have been having issues with the whining, you could try a stronger steel fitting to avoid this, but I have not tested it:
Heidts Power Steering Rack Fittings PS-030

-6AN premade stainless steel hose with steel female -6AN 90 and a straight female -6AN fitting

Fragola Performance Systems 372042 - Fragola Performance Systems P.T.F.E Hose Assemblies - Overview - SummitRacing.com

14x1.5 mm o-ring female to -6AN male adapter

Fragola Performance Systems 491970 - Fragola Performance Systems AN to Metric Adapter Fittings - Overview - SummitRacing.com

Return line:

16x1.5mm oring to -6AN male adapter

Fragola Performance Systems 491971 - Fragola Performance Systems AN to Metric Adapter Fittings - Overview - SummitRacing.com


-6AN male to barb fitting

Summit Racing SUM-220756 - Summit Racing® AN to Nipple Twist-Tite Fittings - Overview - SummitRacing.com

7. I attached all of the high pressure line and return line to the rack first, and laid the hoses along the cross member up to the frame rail and ziptied them to the brake hardlines, and I followed it until just after the airbox. I pulled the high pressure side up and bolted on to the pump, I used teflon tape on the pump side of the adapter.



8. I cut a small piece of the return hose about 3" to clamp one side to the barbed fitting and then hose clamp the other side to the reservoir. Reattach the reservoir then reattach the return hose and reattach the airbox and hose.

Refill the reservoir with ATF (I like the motul synthetic ATF), leave the cap off, jack the car up and put it on stands. With the car off cycle the wheel left to right about 10 times. Start up the car and check for leaks. If there are none, keep turning the steering wheel left to right, checking for bubbles in the reservoir and adding more if needed.

 

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1999 SUBARU IMPREZA RSTI EJ20K
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Got custom ones made from shop in newport for my last subaru for $95. Power steering lines were burnt through by the DP which is fail on the EJ20G engine.

Great Mod!
 

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Questions for the wider DIY community...

Great write up. Thanks for the info.

I have a MY 2000 2.5RS with just bolt ons for mods nad over 178K mi. on the clock. My PS pump is starting to make noise, and I figured I'd replace the hoses as well as rebuilding the pump (seal kits available from PSKits.Com for like $15). I'd like to go with SS braided PTFE, but do not know the hose end fittings to order that connect to the rack and the pump. They are almost certainly different from the STi you described above. Does anyone know what they are? I talked to Techna Fit this morning, and they said that if I could get them the hose end fitting specs, they could fabricate some for me.

I'm also thinking if I can just keep the OEM steel tubing (10mm OD), use a tubing cutter to cut out the existing rubber hose, then use AN-6 adapters and power steering hose to reconnect the two hard lines, I could save myself a lot of work/research. Would a flare fitting to power steering hose similar to brake lines work for this high pressure application?

Any thoughts from the general community would be appreciated. Thanks in advance.
 

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Bump. Looking for adapter fitting information so I can do this mod on my stock RS pump and rack. Are they the same as the STi (2 ea. 14x1.5 o-ring to AN-6 and 1 ea. 16x1.5 oring to AN-6)? Any help would be appreciated.
 

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sorry to zombify this thread. I have a 05 STi and I need to replace my return line from the rack to the reservoir. The above part list doesn't specifically say what hose is needed for the return line. The hard pipe on my car is a bigger diameter than the high pressure line, so I'm not sure if hose listed for the high pressure is supposed to also work for the return.
thx
 

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I too am curious about the return lines. My feed and return lines are both leaking and i want to replace before i have a bonfire in my engine bay. Anyone have any input on the return line from the rack to the reservoir?
 

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1996 Impreza LX
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sorry to zombify this thread. I have a 05 STi and I need to replace my return line from the rack to the reservoir. The above part list doesn't specifically say what hose is needed for the return line. The hard pipe on my car is a bigger diameter than the high pressure line, so I'm not sure if hose listed for the high pressure is supposed to also work for the return.
thx
I used the parts listed on the first page with the exception of making my own line. To make my own line I used -6AN braided steel line (check pressure rating, at least 1,200psi). Along with a 45° Swivel Hose End for the connection to the rack and a 90° Swivel Hose Ends for the connection to the power steering pump. You do not need to use a 90° fitting for the PS pump and can use a straight fitting if you'd like. My preference was to use the 90°.

Nothing is wrong with using the pre-made hose like the OP did but it is cheaper to make your own assuming you are willing to learn how. If you are learning, you will want to buy some extra hose to practice cutting braided SS as it's a pain without fancy tools. (Hacksaw and some duct tape)

Here is a helpful video if you decide to learn to make your own hoses.
https://www.youtube.com/watch?v=KwmvRWuAwno

To answer your question on the return side, my WRX used a hard line that connected to a rubber tube and then the reservoir. The return line is not a high pressure line and thus why a rubber tube is acceptable.
 

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It didnt seem too hard making your own line but it didnt seem like it would be That much cheaper. Again on the return side i want to use the an fittings the op posted and then just use a steel braided ptfe hose from those fittings to the reservoir for the return side. Does that seem logical?
 

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I have completed the mod. I did the high pressure line as the op did and i did the low pressure line with the stainless ptfe hose as well. Looks great and no leaks but my pump is whining like crazy and i know its not bad i just replaced it less than 5000 miles ago anyone else have this problem?
 
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