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3G brake master in a 2G

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bullettdsm

N/T DSM Wiseman
DSM Wiseman
2,609
34
Dec 17, 2004
East Hampton, Connecticut
Thought I would post this up for future searchers out there (plus let you guys know this is an option for us as well as the GS-T and GSX guys). I knew the info was out there so I did some simple searching and it took a while to get the info via search. So I figured with this title, it would be easier to find.

This is an easy peasy upgrade. Advantages are it looks cleaner and the bore on the master cylinder is bigger (1 1/16th inch). The install? Pretty much a direct bolt-on. All you have to do is bend one line (simple enough to do by hand). Also, if you happen to have some special or painted cap, the caps are identical so you can re-use it on the 3G

And this is what it looks like;

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MB
 
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This wasn't a direct bolt-in on my 99 gsx with abs. There was a mismatch in line fittings (inverted flare versus double flare I believe) and while the fittings on your oem lines may screw into the 3g master cylinder ports they may not be really seating properly and draw into question whether or not they will leak or let air in over time. My car's a track car and I had to be sure things sealed (I prefer not to lose my brakes on the track) so I sourced all the proper fittings and replaced the two lines with I think some -3 (or maybe it was -4?) AN lines from the master cylinder over to the abs box.

As for which type was needed on my car... I've forgotten. You'd have to look at your lines to see which type of fitting is there and which is on the 3g master cylinder.

Also, I think while in the OP's case both lines were able to mate with perhaps minimal bending, this may not always be the case. I'm pretty I recall on the dsmlink forums it being posted that folks without ABS had a hard line that could not be massaged into use and had to be replaced with something like a stainless steel braided line.

Anyway, point is before you go advertising this as a drop-in on all 2g's we may want to do a bit more investigation. Sorry that I can't provide all the missing info but I tend to just work through problems and move on :-\ I'm pretty sure we had all the info worked out over at the dsmlink forums for the turbo 2g's, abs and non-abs, but I don't have the time just yet to go gather that to correct the information in this thread.

To the question of what effect the bore has, I can't say how it would affect the stock brake calipers, but when you upgrade to a set of calipers like the Evo 8/9 that are designed to be mated to the 1 1/16" bore master cylinder you get a mushy and very deep pedal. It's actually pretty dangerous on the race track especially if you get a bit of boilover or pad knockback, as you can go so deep as to hit the end of your pedal travel and still not get the braking you need. By mating the properly matched 1 1/16" bore master cylinder to those calipers you will restore the pedal operation to what it was designed.

I am not clear how this would be an "upgrade" to a car with stock calipers (or any calipers designed for a stock-bore master cylinder) because all it would do is shrink the braking "zone" of your pedal play. I'm not sure why you would want to do that unless perhaps you actually like the smaller zone. Now it certainly might be more to your liking as far as pedal feel, and if so by all means do it, but you're not going to brake any better with such a change.
 
Here's my info from previous posts, I guess I should have a write-up on this. Good idea Mark.

As far as pedal feel goes, it's great. If bled properly, as I'd assume EVERYONE is doing after the install, pedal feel is the same as an Evo's. Currently I'm running rear Evo Brembos and front AWD 2 piston DSM calipers with this booster/master cylinder setup and it digs hard when I'm braking.

When you upgrade to Evo brakes, going from AWD DSM 2 piston/1 piston to Brembo 4 piston/2 piston, the BMC must move more (pedal travel) to push enough fluid to force the caliper pistons to clamp onto the rotor. Of course the obvious fix to this is upgrading to a bigger brake master cylinder that's proportional to the caliper upgrade, in this case the 3g 1 1/16". Spongy brake pedal fixed but when one thing changes, so does another unless you compensate.

What I'm trying to say is the brake booster essentially helps you, the driver, engage the brake pedal (using engine vacuum) to stop the car. If the brake master cylinder is over-matched (too big) for the brake booster your pedal feel will be too stiff, almost like you're braking with something stuck under the pedal. This is why it's necessary to upgrade to a bigger brake booster if you plan on upgrading to a Evo sized 1 1/16th" brake master cylinder.

Ideal pressure at the brake caliper is 900-1200psi, according to Wilwood, so (eventually) I plan on testing this setup to see what kind of pressures I'm achieving with this upgrade. Just haven't gotten around to getting the pressure gauges to test it.

gofer said:
I had been kicking around the idea of upgrading to a set of Evo Brembos for awhile, once I finally got a set installed on my 2g the pedal feel was garbage. Remember, even though my car is a GSX it still had the OE GS-T hydraulic brake system on it which is a 7"+8"(8.75" diaphragm) brake booster and a 15/16" brake master cylinder. The pedal felt like a sponge and driving it around town was scary, I had to figure something out before I could take it to the track and have to slowdown from 100+mph.

With the info I pulled from a few threads, including this one, I started putting together a shopping list. My car, being a '97 GS-T w/o ABS, came with a 7"+8" (8.75" diaphragm) brake booster from the factory along with every other DSM, or so I thought.
  • '06 Evo brake booster - 8"+9" (9.75" diaphragm)
    • OE P/N: 4630A14
  • '03 Eclipse 3.0l brake booster - 8"+9" (9.75" diaphragm)
    • OE P/N: MR527043
Above were the two different brake booster upgrades I was entertaining, unfortunately with both fitment could become an issue since they aren't OE for a DSM. After digging around through ASA and the 2g Tech FSM I found this and couldn't believe it...
  • '94 GS-T (still a 2g D32 chassis code) w/ ABS - 8"+9" (9.75" diaphragm)

attachment.php


I ordered the OE DSM 8+9 brake booster from JNZ Tuning and waited, unfortunately JNZ contacted me and cancelled my order because the part is no longer made. I thought about just getting the reman'd Auto Zone part but I really wanted OE Mitsubishi so I did a bit more reading. Since I was entertaining the idea of upgrading to the Evo or 3g booster I researched the reman'd P/N's of their boosters through Auto Zone and found that the 3g reman'd booster is the same P/N as the 2g 9.75" brake booster from Cardone. ---> DSM 9.75" and 3g 9.75"

I was pretty stoked about being able to have a brake booster the size of the Evo's and know that it will bolt into place like stock, so I picked up a 3g 9.75" brake booster.

The next thing I had to find was a master cylinder that was the same size as the Evo's, which is 17/16". That link that Beau posted to the Nissan 300z TT 17/16" had me interested but there wasn't much info on it. Still, I found a brand new 17/16" 300z master cylinder for cheap so I thought I'd give it a shot. I also got a 17/16" master cylinder from a 3g because it came with the brake booster I bought, I just wasn't sure if it would fit as well as the 300z's.

300z Master Cylinder
I installed the 300z master cylinder first (on the stock booster) and checked fitment, here's how it looked. Right off the bat you can tell that both brake hardlines will need to be replaced to get it to work and that there are clearance issues on the strut tower. So, with a bit of "body work" I could get this thing to work if I didn't have a better alternative.

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3g Master Cylinder
I was taking a shot in the dark with the 3g master cylinder but, since I had one laying around, I thought I'd give it a shot and see if fitment was any better. To my amazement the damn thing bolted into place and I was able to re-use one of the brake hardlines.

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It was definitely a no brainer for me, I decided I'd run the Eclipse 3g brake booster and master cylinder and only have to deal with replacing one of the brake lines.

gofer said:
I pulled the stock 7"+8" (8.75" diaphragm) brake booster and compared it to the 3g 8"+9" (9.75" diaphragm) brake booster and you could definitely tell the difference in size.

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The larger brake booster bolted right into place once I convinced my power steering lines it was supposed to go back there, those things are a PITA. I replaced the hardline that no longer lined up with the 3g master cylinder with a 32" Earl's -3AN SS line and (2) -3AN to 10x1.0 adapters.

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The only thing left to worry about is clearance on my SMIM vacuum ports and MAP sensor since they are all tapped into the driverside of the manifold. I got lucky here too, everything fit perfectly...

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:dsm:
 
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Here's my info from previous posts, I guess I should have a write-up on this. Good idea Mark.
Yup. The only reason I posted it up was because I know people who had done it so I then searched on here to find the info wasn't all that readily available.

The titling allows for a little easier access and I'm really glad you (and others) pulled that info on here.

As for real world applications, I personally knew of two 420a's that had this done, one GSX that had this done and one GS-T that had it done. Each one was over a year with no obvious problems. Being a member on ECMLink forums, I know that it is a private forum. Therefore everyone would not have access to this information (as well as the fact that we should have it here on tuners). So I thought it would behoove us to have a receptacle for the info that would be easily found. So thanks for that added info TSiAWD666. Very helpful to know.

And for the bore upgrade, sometimes you think information is just as plain as the nose on your face. I guess the bore size addition I could have explained and expanded on.

Really great additional info guys.

MB
 
I also like to add that the 3g/evo master cylinder and the brake booster is the same in some of the galant models. I got the #42 booster (pictured by gofer above) and the 1 1/16th master cylinder out of a galant. Same with johnmels car also.

My car had ABS and the fittings were exactly the same. Besides bending the 1 line everything was bolt on.
 
As for real world applications, I personally knew of two 420a's that had this done,

MB
Was this on stock brakes? I dont feel like locking up the brakes every time I press the pedal. Just picked up the mbc and I guess I'll go back to the junk yard and get the brake booster.
 
Was this on stock brakes? I dont feel like locking up the brakes every time I press the pedal. Just picked up the mbc and I guess I'll go back to the junk yard and get the brake booster.
One was gsx brakes and one was aftermarkets (I believe Wilwoods). Both said they loved the feel of the brakes. Another good buddy in state here did an awd swap onto his Spyder and went from Wilwoods BACK to gsx. He loves it.
 
This was the order I've done my brakes over the years...
  1. 7+8 brake booster - 15/16" GST brake master cylinder - stock FWD DSM brakes - stock lines
  2. 7+8 brake booster - 15/16" GST brake master cylinder - stock AWD DSM brakes - SS lines
  3. 7+8 brake booster - 15/16" GST brake master cylinder - Evo Brembos all around - SS lines
  4. 8+9 brake booster - 17/16" 3g brake master cylinder - Evo Brembos all around - SS lines
  5. 8+9 brake booster - 17/16" 3g brake master cylinder - stock AWD DSM front & Evo Brembo rear -SS lines
... and my last and final choice has been my favorite for street, mild drag (slowing from 115+mph), and pedal feel. Adding the front Evo Brembos also adds a lot of unsprung weight to the drivetrain, something I really didn't want, and switching back to the stock AWD DSM brakes I couldn't feel any difference in stopping power.

:dsm:
 
I would like to know is this mod better when stopping? I was going to do a EVO brembo brake swap but is it worth it?
 
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1G line at BMC on top is inverted flare M10x1.0, 3G line at BMC on the bottom is bubble flare M10x1.0.
 
Yup, as a few guys have mentioned, stock 2g line ends are M10x1.0 inverted flare and 3g are M10x1.0 bubble flare. If you want to do it right, you'll need bubble flare at the master.
 
I pulled a 3G Master Cylinder from my local junk yard. The one I pulled has a Rod on it. Which extends into the brake booster. I'm just guessing this is the wrong unit. Or can this rod be removed? Any help would be great. Also, what year 3g should I be looking for to get this Master Cylinder?
 
Any 3g will work.

The are a lot of us that have swaped to 3g bb/bm, the flare are different from our 2gs, but there are a few that we are running the stock lines with out any issue, I have heard of oly one thats had a leak on the flare location, but all the rest have had a good luck, I have this set up for a wile and never have had a problem conserning leaks,,,,,

However, I think the best rout to go is, using the right fitting to convert the flare.
 
I think the M.C. I have is from a 2006 GTS. I think the only one from the 3g that can be used is from 2000-2005.
In the research I've done, the BB with the rod coming out of it is on the models with ABS and traction control.

I bought my 3g BB/BMC from a part out on Club3G Forum : Mitsubishi Eclipse 3G Forums and confirmed it with the owner of the car, it was a 2003 Eclipse GT with a 5-speed, no traction control or ABS.

:dsm:
 
^^You can use the one youve got, but youve got to get the booster for it as well because of the rod that sticks out. You can get the booster off a 2001 Galant for sure as the Galant has the very same master cylinder you are describing, and the outside dimensions of its booster is the same as the #42.

To all who are bolting the inverted flare lines to the master cylinder designed for a DPS (drill point seat), this is just plain scary. One of the things I do for a living is building brake lines of all types. When the master cylinder is dry and the lines are drained, why not just take the lines off the porportioning valve and bring em to a shop that fabricates brake tubing and have them cut off the inverted flare and put a DPS flare on the lines for you? Itll cost less than ten bucks and youll have the piece of mind knowing you dont have to worry about cracking your tubes by over- tightening the crap out of them to get the mismatched seats to seal. Not trying to start shite, just a little FYI.:thumb:
 
To all who are bolting the inverted flare lines to the master cylinder designed for a DPS (drill point seat), this is just plain scary. One of the things I do for a living is building brake lines of all types. When the master cylinder is dry and the lines are drained, why not just take the lines off the porportioning valve and bring em to a shop that fabricates brake tubing and have them cut off the inverted flare and put a DPS flare on the lines for you? Itll cost less than ten bucks and youll have the piece of mind knowing you dont have to worry about cracking your tubes by over- tightening the crap out of them to get the mismatched seats to seal. Not trying to start shite, just a little FYI.:thumb:
I agree and I claim ignorance until it was brought to light a few weeks ago. Thanks for the idea, I didn't realize brake shops can cut/modify existing brake lines so I think I may call around and find one that will do it for cheap.

:dsm:
 
I pulled a 3G Master Cylinder from my local junk yard. The one I pulled has a Rod on it. Which extends into the brake booster. I'm just guessing this is the wrong unit. Or can this rod be removed? Any help would be great. Also, what year 3g should I be looking for to get this Master Cylinder?

Do you have a picture of this rod?
 
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