Sti Master Brake cylinder swap Qs

yes. with an extra very.

 

chances are you won't be able to properly bleed it at all and will end up with a lot of air in the abs module. And I have actually experienced this, where the only way to get things to work was to pull the MC and bench bleed it.

I don't think it's necessarily difficult. Just time and fluid consuming.

Are the Sti booster/MC the same dimensions as the Legacy parts? I want to do this swap on my '05 but I don't have much clearance between my MC and FMIC piping.

It seems the STI booster is actually alittle thinner.

 

*Note: for those using a power bleeder: it is not necessary to bench bleed your MC, but for those of you doing it the good ole fashioned you really want to look into it*

I am planning on putting this setup in my car. I currently have the Grimmspeed MC Brace. For those who have done the swap, and are familar with the MC Brace, would you anticipate any conflict with the brace?

it is actually very easy to bench bleed an MC. stick it in a vice, run a couple short pieces of silicone tubing from the ports into the reservior, fill with fluid, pump repeatedly. takes 2 min, makes the whole process go much more smoothly.

the overall size difference was minimal. The booster is just a little bit larger in circumference by about 2 cm. length did not seem to change

Anybody know if the brake fluid reservoir for the LGT is the same as the brake fluid reservoir on the STi? I picked up an '06 STi M/C and booster a little while ago, but it didn't come with the reservoir. Just wondering if I can swap the reservoir that's currently on my car over to the STi master when I have time to do the swap or if I need to pick up an STi reservoir. Anyone know if the reservoirs are interchangeable? Visually they look pretty close...

I believe the bolt patters are different, thus not allowing you to bold your LGT MC to the Sti Booster.

He's asking about the reservoir, not the mc and booster bolting together.

yes. with an extra very.

 

chances are you won't be able to properly bleed it at all and will end up with a lot of air in the abs module. And I have actually experienced this, where the only way to get things to work was to pull the MC and bench bleed it.

 

will "Motive Power Bleeder" help on that??

yep, no need for a bench bleed with pressure bleeder/motive bleeder.

He's asking about the reservoir, not the mc and booster bolting together.

 

Yes...just asking about the reservoir itself...NOT the M/C since I have both the M/C and Booster from an '06 STi...

Sorry I misunderstood. Makes sense. I should be getting my booster/MC combo within the next week. If you have not found the answer by then, I can take a look at both of mine if you'd like.

Sorry I misunderstood. Makes sense. I should be getting my booster/MC combo within the next week. If you have not found the answer by then, I can take a look at both of mine if you'd like.

 

Well, I looked up the pats on OpposedForces and it lists different part numbers for the '05 LGT brake reservoir and the '06 STi brake reservoir. (26451AC010 for the LGT and 26451AC000 for the STi). Now my question is...will the LGT one work on the STi M/C? The port holes visually "look" to be in the same location, but who knows...would have to actually try to fit the LGT one to the STi master to know for sure, but since the one is still installed on my car I can't easily do that. Hmm...was gonna try to do my Booster and M/C swap this weekend, but maybe i'll have to wait and just get myself an STi reservoir. Would hate to take it all apart only to find that the reservoir doesn't fit...

Installing the booster and M/C this weekend. Can anyone clue me in how the booster is removed from the firewall? Do you unbolt it from inside the car, under the dash? I was pulling my clutch last night and gave it a quick look over, but didn't see anything obvious.

yep, there are 4 nuts behind the brake pedal that hold the booster in. The biggest pain in the ass for me was getting those 4 nuts off, for me it was a mixture of contorting and patience.

So you're saying I should send the wife in there with her small hands and a ratchet.....

and while she is preoccupied you should take the opportunity to....errr nevermind.

 

Yes.

^^way ahead of ya.

To my understanding from reading this thread..

 

1. You need a 04-05 STI Master Cylinder and Brake Booster

2. You need the check valve from the STI. Take it out of STI hose and shove it in the LGT hose with a BIC pen(cap off). The bullet side of the check valve goes towards the engine and the flat side goes towards the firewall.

3. Bench bleed the MC before install or use a power bleeder.

4. Make sure the rod length on the new STI booster is the same as the LGT booster

5. Install everything and bleed the brakes.

 

Did I miss anything?

 

Assuming someone who's never done a Master Cylinder before and doesn't have a power bleeder, how long should this procedure take?

Mani-you have a very good grasp of what need to be done. Should make a new thread and make it a sticky.

Mani-you have a very good grasp of what need to be done. Should make a new thread and make it a sticky.

 

Thanks. I took your advice and made a new thread.

http://legacygt.com/forums/showthread.php/sti-master-cyl-and-brake-booster-swap-summary-lgt-181067.html

 

Let me know if there's anything else you would like to add to it.

Posted in the other thread as well, just did mine today. Long story short it helped the pedal firm up a little, but there is still a bit of the "nothing happening" at the top of pedal travel (right as you start to press it down). It did help get rid of a bit of the mush out of the pedal. For the ~100 bucks I paid for the booster/MBC, and a few quarts of fluid for the various flushes I did, I would say it is definitely worth it. Now for pads, SS lines and some ATE superblue.

 

-Steve

Need to adjust your clevis if there is to much take up for your taste.