Welcome to the North American Subaru Impreza Owners Club Friday February 26, 2021
Home Forums Images WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo)

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.







* As an Amazon Associate I earn from qualifying purchases. 
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 03-28-2014, 01:21 PM   #1
freeman.matt
Scooby Newbie
 
Member#: 106540
Join Date: Feb 2006
Chapter/Region: TXIC
Location: San Antonio
Vehicle:
2002 WRX Wagon
Blue blue blue

Default 02 WRX Vacuum/Coolant Hose Install Guide

Warning: This is going to be a lengthy guide with lots of pictures. If I get too verbose and you just want the photos, check out http://imgur.com/a/aqDJt.

Another Warning: I'm no expert, and much of what I've learned about my car has been from this website. I've been running these hoses for about a month now without issue, but something could be lurking under the hood. If you see anything that needs correction in either the writeup or photos, let me know.

Background: My 02 WRX had at least two leaks under the hood. I could smell the coolant leak, and I could hear a vacuum leak (which also made my heater lose heat at idle). Knowing the car is now 12 years old, I decided to go through and replace all of the hoses and hope I remedied the two issues.

Hose Source: I bought a kit off of eBay of silicon hoses from HPSI-Motorsports (their website) which shipped with most of the hoses that I needed. I did have to go back and order a few more, but I think I replaced some hoses that they did not intend or used a slightly different size. Regardless, I liked them and would recommend them to anyone. These are the final lengths/diameters of the hoses that I used.
http://i.imgur.com/RMrvdjE.png

Tools Needed: Nothing specialized. I relied heavily on a beefy pair of needle nose pliers and there are a few nuts that need to come out here and there, so a socket set or wrenches of some sort. Silicon grease was very helpful with getting the new hoses on, use it liberally.

Annotations: In all of the images I've circled the start and stop of the specific hose, labeled some nearby hoses for orientation help, and noted the hose length and diameter (ID) used. I've rounded up on all lengths, so expect to trim to fit. The hose label is alphabetical in the order I replaced them, but the rest of the writeup goes in a more logical sequence designed to minimize intercooler/coolant tank removals.

Begin Writeup

Were I to do this again, I'd pull the intercooler first and get it out of the way. There are numerous writeups on how to do this so I'll leave it to them for the details. I will say that with my brittle 12yo stock hoses, there was a lot of swearing and bloodied knuckles getting it out. This would be a good time to get a silicon IC hose kit and it really goes back in much more easily.

The two hoses below connect to the same fitting which goes into a short thick piece of hose. I did not replace it as it would have probably required pulling the turbo, but if you want to, it's 14mm hose. I believe these are crankcase breather hoses... I ended up having to cut Hose X at the elbow to pull it out as it was too rigid.

Hose E, Passenger Breather: 6" x 12mm
http://i.imgur.com/NAtKD1r.jpg

Hose X, Driver Breather: 6" x 12mm
http://i.imgur.com/WYeglHR.jpg

With the IC still out, go ahead and replace the throttle body coolant hoses. The original Hose V ran through a mesh sleeve which I reused, I'm guessing it's for abrasion resistance or something.

Hose Y, Throttle Coolant Out: 10" x 6mm
http://i.imgur.com/r0Av2nZ.jpg

Hose V, Throttle Coolant In: 12" x 6mm
http://i.imgur.com/Xg1iSHR.jpg

Now you can put your IC back in... it shouldn't get in the way anymore. The next hoses run from the blow off valve. I have the stock boost meter, which is where Hose W goes. It runs through the firewall to the gauge. I replaced the hose all the way to the gauge, but should have only replaced the portion in the engine compartment. The hose in the cabin was still quite supple and it was a pain snaking the new hose up the the gauge. If you don't have a gauge, then you won't have a T fitting in hose U and should just cut a single 12" piece.

Hose U, BOV: 12" x 6mm
http://i.imgur.com/hOrdHf2.jpg

Hose W, Turbo Gauge: 60" x 4mm
http://i.imgur.com/on9WEzR.jpg

Also in this area is the hose running the the brake booster and a vacuum hose running to the gas tank. This hose actually has a check valve in it, so either salvage the one from the original hose (which I did), or get another one. Basically, you want to be able to blow through the hose from the brake booster end into the engine, but not suck anything from it. The tank vacuum hose is in a group of three and it's the one with the simple pinch clamps on it, not the more powerful screw clamps required to contain fuel pressure.

Check valve in original hose
http://i.imgur.com/Bq8MQra.jpg

Hose F, Brake Booster: 16" x 9mm
http://i.imgur.com/yUm3Zk6.jpg

Hose Z, Tank Vacuum: 15" x 6mm
http://i.imgur.com/YvJ1FWT.jpg

More in next post...
freeman.matt is offline   Reply With Quote
Old 03-28-2014, 01:21 PM   #2
freeman.matt
Scooby Newbie
 
Member#: 106540
Join Date: Feb 2006
Chapter/Region: TXIC
Location: San Antonio
Vehicle:
2002 WRX Wagon
Blue blue blue

Default

Now to the other side of the car and some coolant hoses. Do the next three hoses as a stack (ie remove A, C, D; install D, C, A). There are two 12mm bolts on top of the coolant tank you need to remove and one 12mm nut on the side that needs to loosen. Also, to get at the bottom of Hose D, remove the top half of the air filter box.

Hose A, Turbo Coolant: 8" x 12mm
http://i.imgur.com/7cCZjBN.jpg

Hose C, Bottom Coolant: 5" x 12mm
http://i.imgur.com/P94HmGq.jpg

Hose D, Back IC Coolant Pipe: 13" x 12mm
http://i.imgur.com/PagJRhI.jpg

Go ahead and reinstall the coolant tank, then go for the two coolant hoses which run to the pipes on the front of the IC.

Hose B, Front IC Coolant Pipe: 13" x 12mm
http://i.imgur.com/nSkBm1O.jpg

Hose G, IC Coolant Pipe In: 7" x 12mm
http://i.imgur.com/Wo7oOnG.jpg

Now pull off the cold air scoop (it's 2 bolts of unknown size) and swap the two hoses running to the radiator.

Hose H, Left Coolant: 27" x 6mm
http://i.imgur.com/pWen09H.jpg

Hose I, Right Coolant: 22" x 6mm
http://i.imgur.com/5o0IVjj.jpg

These two hoses may vary on your car. I had to replace the radiator last year and there were some adapter parts required to fit newer radiators into the 02 WRX. The overflow hose is probably similar, but you'll likely not have the Uturn hose unless you've done a similar replacement.

Hose J, Coolant Overflow: 19" x 6mm
http://i.imgur.com/pnWHVrI.jpg

Hose K, Coolant Uturn: 7" x 6mm
http://i.imgur.com/EI4lKUV.jpg

Before replacing the air scoop, go to the next post and do the rat's nest. Once those 6 hoses are done, replace your air scoop and go replace some hoses in the turbo control circuit. Hose L is made of two hoses joined together by a coupler.

Hose L, Turbo Relay 1: 3" x 6mm & 17" x 4mm
http://i.imgur.com/qg2ZOyM.jpg

Hose M, Turbo Relay 2: 11" x 4mm
http://i.imgur.com/xRjfdhu.jpg

More in next post...

Last edited by freeman.matt; 03-28-2014 at 04:29 PM. Reason: updated text
freeman.matt is offline   Reply With Quote
Old 03-28-2014, 01:22 PM   #3
freeman.matt
Scooby Newbie
 
Member#: 106540
Join Date: Feb 2006
Chapter/Region: TXIC
Location: San Antonio
Vehicle:
2002 WRX Wagon
Blue blue blue

Default

The last part of the turbo control circuit is made of three pieces around a T fitting. The hose you're replacing also has a restrictor pill in it which needs to be reused.

Restrictor Pill
http://i.imgur.com/oUl5mKw.jpg

Hose N, Turbo Relay 3: (3" x 4mm) x 3
http://i.imgur.com/Wg6Yd0T.jpg

With that done, the last set of hoses is up near the alternator colloquially known as the rat's nest. This should actually be done when you're doing the long coolant hoses (H and I) since the air scoop needs to come out. It consists of 6 hoses. I was able to remove the relay that Hoses P and Q attach to simply pulling one bolt using a ratchet w/ a 3" extender. Go slow and try not to lose your place.

Hose O, Rat's Nest 1: 1" x 4mm
http://i.imgur.com/UUvV2k5.jpg

Hose P, Rat's Nest 2: 9" x 6mm
http://i.imgur.com/84uXooF.jpg

Hose Q and R, Rat's Nest 3 & 4: (3" x 6mm & 2" x 4mm) & (3" x 6mm)
http://i.imgur.com/XqSm1Y7.jpg

Hose S, Rat's Nest 5: 5" x 6mm
http://i.imgur.com/sFemYDx.jpg

Hose T, Rat's Nest 6: 9" x 6mm
http://i.imgur.com/THJ40hE.jpg

And that's all. I ended up having coolant leaks at Hose A and the radiator o-ring, and the vacuum leak was in hose U. Good luck, it's not hard, just somewhat time consuming.

Last edited by freeman.matt; 03-28-2014 at 03:45 PM. Reason: updated text
freeman.matt is offline   Reply With Quote
Old 08-09-2018, 08:18 PM   #4
oc2md
Scooby Newbie
 
Member#: 488800
Join Date: Jul 2018
Location: Maryland
Vehicle:
2004 WRX Wagon
Silver

Default

Maybe it's obvious but how do you get the restrictor pill inside of the tubing? I just ordered the same hose kit as you suggested and they look awesome. Can't wait to put them in this weekend.
oc2md is offline   Reply With Quote
Old 07-23-2019, 11:55 AM   #5
02WRX84
Scooby Newbie
 
Member#: 504001
Join Date: Jul 2019
Default

Great write up man! Great stuff! Where does the hose just below the IACV and to the right of it go?

Iím looking around and notice that there isnít a hose connected there or on the throttle body under the inter cooler. Iím thinking the hose popped off and that they should have a hose connected to each other. What do you guys think?
02WRX84 is offline   Reply With Quote
Old 07-23-2019, 11:55 AM   #6
02WRX84
Scooby Newbie
 
Member#: 504001
Join Date: Jul 2019
Default Hose Problem!

Great write up man! Great stuff! Where does the hose just below the IACV and to the right of it go?

Iím looking around and notice that there isnít a hose connected there or on the throttle body under the inter cooler. Iím thinking the hose popped off and that they should have a hose connected to each other. What do you guys think?
02WRX84 is offline   Reply With Quote
Old 07-23-2019, 12:21 PM   #7
Valarius Starchaser
Scooby Newbie
 
Member#: 459312
Join Date: Dec 2016
Chapter/Region: MWSOC
Vehicle:
2004 WRX Wagon
Hybrid 6MT Swapped WRB

Default

Quote:
Originally Posted by 02WRX84 View Post
Great write up man! Great stuff! Where does the hose just below the IACV and to the right of it go?



Iím looking around and notice that there isnít a hose connected there or on the throttle body under the inter cooler. Iím thinking the hose popped off and that they should have a hose connected to each other. What do you guys think?


Thatís a coolant line

A lot of guys remove it never understood why no matter what climate your in what the gain is to doing it

To my recollection itís a cold start/emissions type system
Valarius Starchaser is offline   Reply With Quote
Old 01-20-2020, 11:42 PM   #8
benders
Scooby Newbie
 
Member#: 181247
Join Date: May 2008
Chapter/Region: MWSOC
Location: Freeport, IL
Vehicle:
2004 WRX Wagon
Silver

Default

Quote:
Originally Posted by Valarius Starchaser View Post
Thatís a coolant line

A lot of guys remove it never understood why no matter what climate your in what the gain is to doing it

To my recollection itís a cold start/emissions type system
I believe it's also to prevent the throttle from icing up in cold. Otherwise the pressure/temperature drop after the throttle plate could form ice and a sticking throttle.
benders is offline   Reply With Quote
Old 04-20-2020, 04:53 AM   #9
evo_nahh
Scooby Newbie
 
Member#: 492988
Join Date: Oct 2018
Default

How are you guys clamping the hoses?
evo_nahh is offline   Reply With Quote
Old 03-28-2014, 01:22 PM   #10
Psychoreo
Scooby Guru
 
Member#: 79643
Join Date: Jan 2005
Chapter/Region: NESIC
Location: The internet
Vehicle:
2021 STI TE
Terminal black pearl

Default

That's a lot of words for "unplug the old hose, match up to the new hose, plug in the new hose"
Psychoreo is offline   Reply With Quote
Old 03-28-2014, 01:24 PM   #11
freeman.matt
Scooby Newbie
 
Member#: 106540
Join Date: Feb 2006
Chapter/Region: TXIC
Location: San Antonio
Vehicle:
2002 WRX Wagon
Blue blue blue

Default

Indeed it is. The high yield stuff here is the table showing overall lengths and diameters required. The rest is just for thoroughness.
freeman.matt is offline   Reply With Quote
Old 03-29-2014, 01:07 PM   #12
silverstreak02
Scooby Newbie
 
Member#: 316307
Join Date: Apr 2012
Chapter/Region: South East
Location: Kannapolis, NC
Vehicle:
2002 Impreza WRX
Silver

Default

Looks really good, was doing some work under the hood this weekend and was going to order a few small hoses to replace, but now I see there's a full kit I can buy..great post
silverstreak02 is offline   Reply With Quote
Old 03-29-2014, 03:34 PM   #13
rdieder
Scooby Specialist
 
Member#: 257818
Join Date: Sep 2010
Chapter/Region: SWIC
Location: ABQ, NM
Vehicle:
2007 STi
CGM

Default

What are the closest sizes in non metric? The AutoZone near me has nearly all bulk hose in standard measurements.
rdieder is offline   Reply With Quote
Old 05-08-2014, 12:04 AM   #14
big_dog35
Scooby Newbie
 
Member#: 273299
Join Date: Feb 2011
Location: Miller Place, New York
Vehicle:
2003 bugeye wrx
WRB

Default

Great write up man, gettin at this real soon! Been waitin for a DIY like this for a while. It's nice to be able to see and plan it all out before gettin at.
big_dog35 is offline   Reply With Quote
Old 05-08-2014, 02:56 PM   #15
CJ12
NASIOC Supporter
 
Member#: 202539
Join Date: Feb 2009
Chapter/Region: Tri-State
Location: NJ
Vehicle:
02 WRX MBP 6SPD
94 LandCruiser/84 NH 650

Default

I for one appreciate write ups just like this. Plenty of useful information and colorful pictures that show relevant detail. Thanks!

I'm a couple of steps away from buying an ancillary hose kit and will reference this when I do the install.
CJ12 is offline   Reply With Quote
Old 05-10-2014, 04:35 AM   #16
lamby
Scooby Newbie
 
Member#: 237869
Join Date: Feb 2010
Location: queens, ny
Default

Thank you so much for this. I was looking everywhere. Kind of lost on hose T though. Could you post a better picture?
lamby is offline   Reply With Quote
Old 05-11-2014, 11:55 PM   #17
Garo
Scooby Newbie
 
Member#: 390554
Join Date: May 2014
Default

Nice upgrade to get ride of the old ones and ensure no leaks.
Garo is offline   Reply With Quote
Old 05-12-2014, 03:00 PM   #18
bleuquila
Scooby Specialist
 
Member#: 31922
Join Date: Jan 2003
Chapter/Region: SWIC
Location: new mehico
Vehicle:
03 wrx wagon
78 brat

Default

Amazing post and very timely for me - someone else took all my hoses off, and it's been a real headache getting everything reconnected from the bucket of hoses n' bolts. Like a really expensive 3d jigsaw puzzle. I knew I was going to need to replace your "hose b" to the IC, I trimmed my stock one too short when putting in a new inlet and now it doesn't route the way it should. So now I'm sort of fired up to replace all the hoses while I'm at it!
bleuquila is offline   Reply With Quote
Old 05-12-2014, 05:46 PM   #19
taylor_90
Scooby Newbie
 
Member#: 389932
Join Date: May 2014
Chapter/Region: SWIC
Location: Phoenix, AZ
Vehicle:
2005 WRX STi
2019 WRB WRX

Default

Very helpful thanks. Nice write up
taylor_90 is offline   Reply With Quote
Old 08-08-2014, 12:49 PM   #20
mathiasddr
Scooby Newbie
 
Member#: 181206
Join Date: May 2008
Chapter/Region: TXIC
Location: Houston, TX
Vehicle:
2002 Impreza WRX
Silver

Default

I've been thinking about replacing the hoses under the hood for a while now, still not having any issues related to the work you did? Also, thanks for the great write-up, it looks like something I would make.

Since we both have older model bugeyes, I feel I should mention that you should check your trunk seal for rust, if you remove it just get some silicone RTV adhesive for a quick reinstall. If your dashboard clock goes out it's a quick solder job with removal of the clock from the dash being the hardest part, and take care to wash down your engine every once in a while as well as cleaning your MAF sensor (both sides and inside where you can't easily see) to keep a smooth idle. Just some stuff I've had to take care of over time.
mathiasddr is offline   Reply With Quote
Old 08-08-2014, 05:56 PM   #21
kaminaricelica07
Scooby Specialist
 
Member#: 113042
Join Date: Apr 2006
Chapter/Region: South East
Location: Charleston, SC
Vehicle:
2012 STi Hatchback
Plasma Blue Pearl

Default

I just order this same set today after seeing your post. Might be ordering more by the foot as I see fit. Thanks for the write-up!
kaminaricelica07 is offline   Reply With Quote
Old 08-10-2014, 02:28 PM   #22
Dn41387
Scooby Newbie
 
Member#: 202895
Join Date: Feb 2009
Chapter/Region: NWIC
Vehicle:
2005 Sti,2005 Wrx
2000 Rs coupe

Default

Thanks, great post,will be very helpful pretty soon for me.
Dn41387 is offline   Reply With Quote
Old 08-11-2014, 11:52 PM   #23
kabz
Scooby Newbie
 
Member#: 351744
Join Date: Mar 2013
Chapter/Region: TXIC
Location: Northwest Houston
Vehicle:
2004 WRX Wagon
SRR

Default

Awesome write-up. This'll help when I put my blobeye back together, though I did take pics and save and label all hoses and anything that would fit in a ziploc.

Hoses D and G (I'm fairly sure) are the head breathers that are Y'd together by the IC hard-line, and routed to the turbo inlet via Hose B. I guess they get routed like that so they don't end up heating the inlet air any more than they have to. [You have them labeled as IC coolant lines]

Last edited by kabz; 08-12-2014 at 12:09 AM.
kabz is offline   Reply With Quote
Old 11-09-2014, 05:29 PM   #24
Luuuuukebradley
Scooby Newbie
 
Member#: 377050
Join Date: Dec 2013
Vehicle:
2002 WRX
WRB

Default

Hey I was wondering if you had to drain the coolant in order to change Hose A: turbo coolant hose.

Thanks,
Lucas
Luuuuukebradley is offline   Reply With Quote
Old 11-10-2014, 12:59 AM   #25
Brother EddieJ.
Scooby Specialist
 
Member#: 181617
Join Date: Jun 2008
Chapter/Region: MAIC
Location: frederick, md
Vehicle:
2004 wrx
Dom3/IAG built hybrid

Default

Quote:
Originally Posted by Luuuuukebradley View Post
Hey I was wondering if you had to drain the coolant in order to change Hose A: turbo coolant hose.

Thanks,
Lucas
Nope just suck some out with a turkey baster.
Brother EddieJ. is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -4. The time now is 06:34 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2021 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.