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2 pot rear calipers on a BH/BE


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Has anyone put 2pot rear calipers on a BH/BE legacy. I know they have the multi-link set up so later model wrx hubs won't fit. And getting adapters made would require a cert.

Just seeing what other options there are to fit them.

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 Optical said:

pretty sure there are 2 pots on some BH/BE from factory, you'll just have to find those particular hubs from somewhere

im beginning to think that as wlel have seen a number of them that seems to common to be someone converting them.

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subaru sell a complete backing plate, which was used in the S401. Only BE/BH to have 2pots on rear.

Adaptors would be alot cheaper.

*FYI

A few Forums ago, there was a complete DIY guide to do a 4/2pot conversion on a BE

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Booya Saved the below in Word. Unfortunately no happy snaps :'(

 
What you will need:

Floor jack or something to get the car safely in the air.

Jack Stands - to keep it there

Torque wrench - for lug nuts and other things

19mm socket - to remove lug nuts

17mm open end or sockets - To remove caliper bolts

14mm open end - to remove brake line banjo fitting from caliper

8mm open end - for bleeders

Brake Fluid - I purchased a 32 oz. bottle and had plenty left over

Brake parts cleaner - to clean rotors when you are done

2 - 8mm standard pitch tread bolts about 1" or better long in case the rotors are suck on the hub

A one man brake bleeding kit, or recruit someone to help bleed the brakes

Bucket - or something to catch the brake fluid that comes out of the line you remove from the caliper

2 brake line sealing washers - for the Banjo fittings that go on the caliper

How to do it:

I actually dreaded doing this install but turned out to be fairly simple. Get the car safely in the air and remove the front wheels, the lug nuts are 19mm. Put a bucket under the caliper and with a 14mm wrench or socket, remove the brake line from the caliper. (fluid will start leaking out - brake fluid will remove paint clean it up quickly) There will be a washer and a bolt like thing that holds the line in place, save the bolts but use new sealing washers. Sorry I don't know the part number. With a 17mm open end or socket remove the 2 bolts holding on the caliper. They are on there fairly tight. I could use a breaker bar on the bottom Bolt but the top one in close quarters and I had to use an open end. I used the locking wrench trick to get more leverage.

Once you remove the caliper, put that aside, now it's time to remove the rotor. If you're lucky it will just come off no problem. Just tug it straight off the wheel studs. The first one I did was stuck, but the second came off no problem. If it's stuck, there are 2 threaded holes between the wheel studs that will take 8mm standard pitch tread bolts. Put those in and turn them in

as evenly as possible, the rotor will come right off.

Next put the new rotor in place. My kit didn't include the dust shields. You really don't need them but I found that the ones there fit fine. I just pushed the shield in a little with my hand to give it a little more clearance.

Now put the 4-pot caliper in place. Be sure to place the caliper with the bleeder valve on the top and not the bottom. If you don't you will not be able to properly bleed the brakes. Air will get trapped. The 2 /17 mm bolts that hold the caliper on should be torqued to 51-65 ft/lbs. Now prepare the brake pads for installation into the caliper. There are 4 pads. Two of them have wear indicators on them and two don't. (see pics below) Make sure each caliper gets a pad with the indicator. The pads appear the same other than the indicator; I don't think it matters if it goes to the inside or outside of the rotor. Find that copper colored packet and cut a corner of the plastic. This is the anti-squeal compound. Put some on the back of each pad, then put the vented shim, more compound, the solid shim and a little more compound. On the top of each pad, fit one of what I call "locating clips". Those small gray metal things. You should have 4 of them one goes on the top of each pad (see pics)

Slide the assembled pad in the top of the caliper. Push it in till the holes in the pads line up with the holes in the caliper. The two holding pins will come through the holes and secure both pads . Watch the position of the top locating clip, it's a pain to get in properly. Now put the long holding pins in from the outside of the caliper to the inside. If the shims didn't move this will go smoothly. If they have shifted it's a pain. After the pins are in, take the long wire, with the bent ends and hook in the center, and put the ends of the wire though the holes in the pin ends. Then put the hook in the hole in the caliper. See pics below to get a better understanding of this. Next install the anti-rattle clip. The small end hook goes under the top pin and the long loop clips over the bottom pin. Again look at the pics.

Next re-attach the brake line. I was installing Stainless Steel brake lines at the time an they came with new sealing washers for the banjo fitting. From what I understand you are supposed to replace the washers with new ones. Torque the banjo bolt fitting (14mm) 132-180 inch lbs (according to my Haynes Manual). Use brake parts cleaner liberally and spray the heck out of the rotor to clean it. Make sure there is no grease or brake fluid on the rotor front or back.

Now you are done with the first side time to do the other one. After you do both sides you need to bleed the brakes, do all the calipers not just the fronts. According to Cobb Tuning you should bleed the brakes w/ ABS in this order Front R, Rear L, Front L, Rear R No ABS this order - RR, RL, FR FL

After bleeding the all 4 brakes torque the wheels down I use 70 ft/lbs.

Now you are done

Take it easy on the brakes when they are new try not to kick in the ABS if possible. The silver on the rotors will wear off after the first few stops.

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This was the one I was talking about:

I’ve prepared these notes in the hope that they will help other BE/BH Legacy owners who are contemplating this brake upgrade. I performed the upgrade on my 2002 JDM-spec Legacy B4-RSK (twin turbo) – some additional research may be necessary to complete the upgrade on other models. Much of this information will also apply to owners wishing to install the Brembo brakes from the WRX-STi – notes on this appear toward the end. If you spot errors, please contact me so I can make corrections.

Apparently the four-pot front brakes first appeared on the STi v3. The full 4-pot front/2-pot rear arrangement debuted on the 1997 STi v4 RA, and appeared on the 22B the following year. Since then, they've been used on a variety of models in the Subaru line-up, and remain STi’s homologated gravel brake set up for Group N cars (as they will clear many, but not all, 15” rally wheels):

http://www.subaru-sti.co.jp/e/GRN/tec_info/1.html

Much background information on these upgrades can be found in a thread by “Dendrobium”, published on the NASIOC forums:

http://forums.nasioc.com/forums/showthread.php?t=623187

Dendrobium was concerned with upgrading an Impreza. While up to 1999, the Legacy and Impreza shared virtually identical MacPherson strut suspensions front and rear, the 3rd generation BE/BH Legacy introduced a multi-link rear suspension. The only write up I could find that addressed the rear upgrade of this suspension is written in Japanese, although Dendrobium kindly provided Babelfish translation links. The “Babel-english” is entertaining at times, and totally incomprehensible at others, but with the extensive photos, the site is a very helpful reference for us Legacy owners. I’ve reproduced these links below:

In Japanese:

http://homepage2.nifty.com/~legacy/mainte/4pot/4pot-change.html

http://homepage2.nifty.com/~legacy/mainte/rear2pot/2pot-change.html

Translated by Babelfish:

http://www.babelfish.altavista.com/babelfish/trurl_pagecontent?lp=ja_en&trurl=http%3a%2f%2fhomepage2.nifty.com%2f%7elegacy%2fmainte%2f4pot%2f4pot-change.html

http://www.babelfish.altavista.com/babelfish/trurl_pagecontent?lp=ja_en&trurl=http%3a%2f%2fhomepage2.nifty.com%2f%7elegacy%2fmainte%2frear2pot%2f2pot-change.html

I’ll comment briefly on the 4-pot front conversion, but as this is very straightforward and well covered elsewhere, the bulk of this report focuses on issues relevant to the Legacy, particularly the rear.

FRONT 4-POT:

The 4-pot brake upgrade is a simple bolt-on procedure, provided your car is fitted with the 294 mm (11-9/16”) vented rotor. Just exchange calipers, bleed, and you’re done. If you have another size rotor, you will need to obtain new rotors, and you may also need to purchase new backing plates to provide correct mounting position for the caliper (I have not done the research on this). You will of course need the caliper assemblies for each side (the bleeder should be oriented at the top), complete with pads. When I sourced these from local wreckers, I felt it would be necessary to recondition the calipers and install new pads before use. After reconditioning, it turned out that there would be little saved over the price of new calipers, so I went that route.

Parts required:

Front calipers, left and right (for a 2006 Impreza WRX, or equivalent: these are red, but other colours were used in some other models of Impreza and Forester as standard)

Cross springs (2)

Brake pad pins (4)

Pad kit (comes complete with shims, retaining springs and other necessary parts)

New brake hose gaskets

Approximate cost NZ$ 1,100.

If you want to use non-OE pads (as I did), you can try to purchase the shims and other pad hardware separately, but I was told this was no longer possible (you may get lucky and find a dealer with old stock). Purchase the Subaru pad kit, and simply swap out the pads for the compound of your choice. The Subaru pads will stay on your shelf as spares.

The front caliper swap can be made with simple tools. Remember that anti-seize compound is your best friend if you ever need to revisit any of this assembly – get in the habit of using it!! Be sure to bleed the brakes correctly. The bleed order for all Legacys with ABS, regardless of left or right steering wheel location, is: (1) Front right, (2) Rear left, (3) Front left, (4) Rear right (Subaru Service Manual Legacy/Outback 1998-2003).

REAR 2-POT

If the rotors on your Legacy are 290 mm (11-7/16”) and VENTED, then you can rest easy. This is the case with all B4’s, but other models, including USDM Legacy’s have SOLID rotors, and these are too thin. While swapping rotors is straightforward, be aware that you may have issues with the diameter of the parking brake. The 290 mm vented rotors use a 170 mm diameter parking brake assembly.

Regardless of what rear rotor your Legacy had as OE, the mounting holes on the 2-pot caliper will NOT match those on your backing plates. One solution is to modify the backing plate itself. It seems that a Japanese firm known as Flatt Racing (http://www.flatt-racing.com) used to sell modified backing plates as part of a kit to carry out this exact conversion. Unfortunately, they don’t seem to answer emails, and they are clear about their sales being restricted to Japanese customers.

I originally thought I could use backing plates from a 2002+ WRX. Afterall, they use these same calipers. The caliper mounting holes are in the right place, but the mounting holes to the swing arm and the hub clearance holes are not. Furthermore, most of parking brake parts on the WRX are also different (despite being the same 170 mm diameter used on the Legacy). So, I ruled out modified backing plates and went in search of adapter brackets instead.

The only bracket I could find specifically for this conversion application is advertised in Japan by DSpeed for 35,000 yen (http://www.dspeed.co.jp/hard/) but I was unable to get any response from the company in English, either by email or telephone. Having a bracket made here in NZ would have been possible, but it is not a trivial piece of engineering or fabrication. I opted to purchase brackets from the Tuning Factory (http://www.tuningfactoryinc.com), located in Michigan, USA. The brackets they sell are intended for conversion of standard Impreza single pots to Brembo 2-pots (they company also sells a reduction ring to downsize the larger 190 mm parking brake hub of the larger rear rotors to the 170 mm diameter on the non-STi Imprezas). I figured this bracket would be close to perfect, as the bolt locations on both the Brembo and STi 2-pot calipers are the same (theoretically!).

Well, it turns out the bracket was close, but not perfect. Some of the machined angles near the caliper mounting surface were radiused. Had I access to a milling machine, I could have easily converted these radiused corners to 90-degrees, but without this capability, I had to work carefully with a grinder and files to remove material on both the bracket and the caliper. I also had to remove some material on the bracket to clear the body of the caliper piston housing. After fiddling with all that, I finally got everything to bolt on the car, only to discover that the caliper was sitting about 2 mm too far from centre. To compensate, I ended up having rear pads custom-made (not really that expensive, just inconvenient) with the pad material offset by 2 mm.

If I were doing the mod again, I would try to locate a Japanese-speaker who could call on my behalf to the folks at DSpeed, and order the “perfect” fitting bracket from them. Judging from the lack of response, the folks at the Tuning Factory don’t seem interested in fabricating a BE/BH Legacy-specific part.

Parts required:

Rear calipers, left and right (from a 2006 WRX, or equivalent -- these are red, but other colours were used in some other models of Impreza and Forester as standard equipment)

Spring clips (2)

Retaining pins (4)

Pad kit (comes complete with shims, retaining springs and other necessary parts)

New brake hose gaskets

Mounting adapter plates

Approximate cost NZ$1000.

Remember to bleed the brakes in the proper sequence, given earlier above.

SPARE TYRE

Chances are your original space-saver spare tyre will NOT fit over the new calipers. I simply went to a wrecker and purchased one from a 2002+ WRX for $20.

CERTIFICATION

Consult your local fitness certification requirements. While pad and rotor changes are usually “free”, if the same rotor size is used, there may be a requirement to have upgraded calipers and rotors certified. I was able to have my car certified for NZ$280.

OPTIONAL

As illustrated in the photo essay, I decided to make two other brake upgrades simultaneously, although I could have continued to use the OE parts on my B4:

(1) Brake hoses upgraded with Goodridge SSU0102-6 SS kit, with fmvss106 certification, shipped from UK for £108.

(2) Rotors upgraded DBA4000 slotted: front 4650SL/SR, rear 4653SL/SR at NZD$268 each

OLD PARTS HAVE VALUE!

All this added up to pretty hefty bill. I was able to lower the final amount by some $275 by selling my old calipers and rotors on Trademe.

UPGRADING TO BREMBOS

If you want to upgrade your Legacy to the Brembos used on the WRX-STi, there are a few other things to keep in mind. First, wheel clearance is more of an issue – 15” wheels are definitely out, but other larger diameter wheels may also have issues. Second, you will definitely need larger rotors. This shouldn’t pose any problem on the front, but the rear rotor must also have the correct emergency brake diameter. Those listed for a WRX-STi will have a 190 mm diameter emergency brake, while the Legacy is 170 mm. Your options are to find someone who makes the appropriate rotor, or to use an adaptor ring with the WRX-STi rotors to down-size the brake drum (available from www.tuningfactory.com, and perhaps others).

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I Still have photos from that thread somewhere, along with links to a few sites that sell brackets/backing plates etc etc on my External drive at home. I'll have a look when I fly back.

I think I got 41 to price up the D-speed brackets which came to about $470 odd to my door. That was about 4 years ago now...

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  • 1 month later...

i want to do the same thing on my B4 RSK what hubs could i put on so i dont need a cert? have tried to use search but cant find the answer!

i would prefer to change the hubs as i love the more stock look and idea! i have the 5, twin spoke rims so i believe they will clear the 2pots

cheers guys

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As said before, you cant change hubs over.

If you want the stock look, then you going to have to buy the S401 backing plates. ($$$$!!!)

Or modify your backing plates to adapt the 2pot mounting holes...

Or use aftermarket dogbones and get a cert.

EDIT:

Part numbers for S401 backing plates:

RH 2670466000

LH 2670466010

You can only get these parts if you own a S401 or know the chassis code of one.

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 D-Style said:

As said before, you cant change hubs over.

If you want the stock look, then you going to have to buy the S401 backing plates. ($$$$!!!)

Or modify your backing plates to adapt the 2pot mounting holes...

EDIT:

Part numbers for S401 backing plates:

RH 2670466000

LH 2670466010

You can only get these parts if you own a S401 or know the chassis code of one.

so what if i get some B4 backing plates CNC'd but with the mounting holes of an STI backing plate made into it? (aka cutting my backing plate mounts and putting on STI mounting holes - but made in 1 piece)

what would i need to do after this is done for the 2pots to work/fit? EBrake?

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If you going to do that, why not try a rear 4 pot conversion?

If you going 2pot:

Only thing you need really is the Handbrake gear. If you keep to the 170mm hand brake, then just re-use that.

As you can see, you can get larger diameter rotors but with the 170mm dia drum, so this would be the easier thing.

If you using Brembos, then you need to have the brembo caliper mounting bolts and brake hoses that fit the brembo banjo fitting.

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 D-Style said:

If you going to do that, why not try a rear 4 pot conversion?

If you going 2pot:

Only thing you need really is the Handbrake gear. If you keep to the 170mm hand brake, then just re-use that.

As you can see, you can get larger diameter rotors but with the 170mm dia drum, so this would be the easier thing.

If you using Brembos, then you need to have the brembo caliper mounting bolts and brake hoses that fit the brembo banjo fitting.

4pot conversion? the same as on the fronts?

I was planning on doing the subaru 2pot rear conversion, not the brembos cause they are too expensive! lol

all this talking has been good, cause ive learnt loads (i knew nothing about this before!)

but i think i need to meet up with some one who can show me the parts so i can visualize it.

any takers?

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Here are some pics I had on my Hard drive from a few years back when I still had my Biltzen.

Most of these website are Japanese, and after checking other day, most no longer exist.

al_armlink.jpg

Wheel off shot showing 2pots

caliper_back.jpg

Showing "dogbone" bracket use to mount 2pot

brembo_scm.jpg

One type of adaptor bracket

EifelSusR.jpg

Disc rotor off showing Handbrake setup

shoe.jpg

CLose up of setup

hub_puller.jpg

Pulling Hub off

hub_unit.jpg

View of Rear Hub. Much Different to WRX type.

housing.jpg

Rear Suspenion arm with Backing plate and hub removed.

backplate.jpg

S401 Backing Plate

brembo_rl_02.jpg

S401 Rear Setup

trailarm.jpg

Trailing arms. Top Cast arm is from BE/BH Gen III Legacy

Bottom Alloy one is from BP/BL Gen IV Legacy

Not even close to being same as WRX arms.

back_plate.jpg

This is one other method of Mounting 2pots. They have cut n welded in new Adaptor brackets to the OEM Backing plate.

rotor_space.jpg

shoe1.jpg

Handbrake shows which have been re-shoed for the larger 190mm handbrake drum of the brembo Rotor

braketo2.jpg

Another conversion

2pot1-1.jpg

2pot and bracket

absorber1.jpg

Front shocks

absorber2.jpg

Rear Shock for BE/BH legacy

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