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2nd-Gen LGT Brake Upgrades: WRX front and H6 Rear


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I'm think the dealer replaced the master cyl a few years back for the original owners, I will have to review the service records to be sure.

 

This. I had my master cylinder changed out under a recall, and everything was bled properly and new fluid put in and whatnot. Even with the same older pads on back then, I noticed better pedal feel with the new cylinder in. Now with my new gear, it feels great, but yeah I know what you mean about the softer brakes compared to other cars. My dad's audi grabs and doesn't let go; it's night and day compared to my subaru.

 

That 7-series master cylinder swap is an interesting idea...do you think there's a larger master cylinder out there from a fozzy or something that could be swapped in to ours for some extra power to the brakes? Or is there an aftermarket upgrade that we can pick up?

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Though since you replaced your brake system completely I would replace the master cylinder. The seals in it are definitely worn out.

 

-Sean

 

This. I had my master cylinder changed out under a recall, and everything was bled properly and new fluid put in and whatnot. Even with the same older pads on back then, I noticed better pedal feel with the new cylinder in. Now with my new gear, it feels great, but yeah I know what you mean about the softer brakes compared to other cars. My dad's audi grabs and doesn't let go; it's night and day compared to my subaru.

 

I've just checked the service records on my wife's LGT. The original owners had the master cylinder replaced in late '99 under dealer recall, at about 30K. The car now has 110K.

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Well, everything makes sense now, LOL. Thanks for looking into it. WESTcoast, would it be okay if I asked you to make a quick edit to your post in the Second Gen. Aftermarket Parts and Upgrade Guide thread to include full H6 rear calipers and brackets in your list of necessary supplies for this rear brake upgrade? Just to keep the information consistent and help avoid confusion for the next guy. I really valued the information you provided in these threads! This is your post: http://legacygt.com/forums/showpost.php?p=3259551&postcount=188

 

Thanks! :)

 

changed and changed!!

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This. I had my master cylinder changed out under a recall, and everything was bled properly and new fluid put in and whatnot. Even with the same older pads on back then, I noticed better pedal feel with the new cylinder in. Now with my new gear, it feels great, but yeah I know what you mean about the softer brakes compared to other cars. My dad's audi grabs and doesn't let go; it's night and day compared to my subaru.

 

That 7-series master cylinder swap is an interesting idea...do you think there's a larger master cylinder out there from a fozzy or something that could be swapped in to ours for some extra power to the brakes? Or is there an aftermarket upgrade that we can pick up?

 

It would definitely be interesting to see if there was a bigger master cylinder. I believe the STI master cylinder is a bit of an increase, so it might be something to consider installing. Remember you did increase the size of the bore for your brake pistons without also increasing the size of the Master Cylinder bore. Both must remain within a certain ratio or pedal feel will change, barring the age of failing rubber gaskets or brake fluid.

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It would definitely be interesting to see if there was a bigger master cylinder. I believe the STI master cylinder is a bit of an increase, so it might be something to consider installing. Remember you did increase the size of the bore for your brake pistons without also increasing the size of the Master Cylinder bore. Both must remain within a certain ratio or pedal feel will change, barring the age of failing rubber gaskets or brake fluid.

 

In actuality, the brake caliper piston sizes are exactly the same as stock with this swap. The front WRX 2-piston calipers are identical (except for the taller mounting brackets) to the LGT 2-piston calipers.* The rear H6 1-piston calipers are not identical to the rear LGT 1-piston calipers, but are similar in overall size. I believe the H6 rear pistons are the identically sized as stock, however. It is the rotor size increase that is the primary aspect of the WRX/H6 upgrade.

 

Nonetheless, an improved master cylinder would be a welcome upgrade.

 

 

*When using MY2002 WRX front calipers, as I did.

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yep brake bias stays the same as does the piston surface area. You're increasing brake torque and heat capacity only.

 

When upgrading cars with 1-pot fronts you do end up with more piston area and pedal travel and bias issues. With my old 93 I had wrx fronts and h6 rears, which did maintain stock bias, but there was a noticeable increase in pedal travel since the piston area had gone up on all four corners. I think that car only had a 15/16 MC.

 

legacy777 has a very handy brake math spreadsheet on his site somewhere with all this info.

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yep brake bias stays the same as does the piston surface area. You're increasing brake torque and heat capacity only.

 

When upgrading cars with 1-pot fronts you do end up with more piston area and pedal travel and bias issues. With my old 93 I had wrx fronts and h6 rears, which did maintain stock bias, but there was a noticeable increase in pedal travel since the piston area had gone up on all four corners. I think that car only had a 15/16 MC.

 

legacy777 has a very handy brake math spreadsheet on his site somewhere with all this info.

 

So since I have an L I should get a GT Brake Master cylinder or do you have a recommendation for an upgrade? I plan on doing WRX fronts H6 rear.

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I think the GT has a 1 1/16 MC which would be good and means less pedal travel and more effort- i.e. better brake feel. If you don't have ABS the SVX non-abs master cylinder is the way to go.

 

My L seems to have come with every factory option available. So I do have ABS.

 

Any other Brake Master Cylinders other then the GT that would work? Or just go with a GT one ?

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Let me know what you guys come up with. I will just buy new from napa or autozone. I just currently don't have money to throw around since I am going to have a new engine put in.

 

Along with Group N STI Engine Mounts, STI Pitch Stop, and Grimmspeed phenolic spacers.

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it needs to be from an older car unless you want to swap the brake booster too. As far as I know the LGT and SVX were the only cars to get the 1 1/16 MC that will swap right in. If I was going to go through the trouble I would probably also try to find a single diaphram brake booster. I *think* that most 1st gen imprezas came with them and they are also on some 2nd gen Legacys.

 

centric part numbers are:

 

130.47023 - abs LGT MC (need to confirm it's actually 1 1/16)

130.47019 - non-abs SVX MC

Edited by jamal
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  • 2 weeks later...

I am revisiting this because I have been thinking about it. Does anyone know if an 02-07 WRX brake master cylinder and booster would be interchangeable and how hard it would be to do?

 

Seems I can get an 04 Master Cylinder and brake booster from autozone for a hair over $200 any other things I would need?

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BTW how is everything on the LGT going camron?

 

Our LGT wagon has been running great. It is now my wife's daily, and she is very happy with it. No more instances of overheating. I think I still have a leak in the sunroof area, so I will be checking on my earlier repair there - the front passenger footwell is getting soaked again. :/ Just got some new custom Weathertech floor mats. Getting antsy for some warm spring weather so I can buff and polish the paint. Waiting on delivery of the JDM tails from a certain forum member (hi Zeus!) :D

 

The 4EAT shifts a little rough from 1-2, which I hear is normal, and sometimes under moderate throttle it shifts a little slow from 3-4 (getting on the freeway, etc.). At some point I will be doing a drain-and-fill with some Redline ATF. Seems the reading on the ATF dipstick is somewhat high, even when the tranny is nice and warm. Tranny fluid was regularly serviced by the dealer with the original owners, so I'm not too worried about it yet.

 

Pretty happy with the brake upgrades. We've gotten used to the "pedal feel" I was wondering about a few posts back.

 

you didnt paint your new calipers.. fool!!!.. my remanufacterd calipers turned orange in 2 weeks!!!! i had to take them off and paint them.

 

Lookatmyrust was absolutely right here... the remanned calipers - even though they were pre-painted by the remanufacturer - are starting to cosmetically rust up. :/

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arent you planning on the 5spd swap in the near future? You must document the brake swap if you do them much like this tread.

 

BTW how is everything on the LGT going camron?

 

There is a lot of I have planned. I need to get these STI mounts installed but cannot find anyone local on any forums to respond to give me some assistance on installing them. Not feeling like I want to crush my hand.

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