WRX Brakes: 90 Legacy Wagon - Issue?

[SWRT]

I installed 03 WRX brackets, calipers and rotors on my 90 Legacy wagon this weekend and I really dont feel an increase. I bled the brakes and got fresh fluid in the system, but they still feel a little spongy. I really expected the 2-pot system with a bigger rotor to have a much harder brake feel. I pumped them up after it was done and they feel ok...they just dont feel any better than my old brakes used to.

Could there still be air in the lines?
Or do all the WRX calipers feel like this?

The front lines were pretty much dry due to a problem with not being able to get the old bleeder
screw to come out of one of the calipers, but the master cylinder still had fluid in it. I finally let the bleeder soak with some PB Blaster overnight and got it out and replaced it. The pistons collapsed alright when I installed the calipers. They were a little rusty, but it didnt seem to do anything and while bleeding them they were collapsing smoothly.

Did I do something wrong?

[speedmaxx]

Umm I did the same upgrade in my 93l. The feel of the pedal still sucks it's just not very responsive, although my stoping distances were deffinatly shorter. So I don't really think u did anything wrong, I plan on changing the brake lines to hopfully tighten up the pedal some, I also read u can go to a slightly larger master cylinder which will help by increasing the pedal force.

[SWRT]

Man, that's disappointing. I wonder if stainless brake lines would help since they dont flex as much. And are you talking about a master cylinder from another vehicle or something aftermarket?

[evolutionmovement]

The biggest difference I noticed when I went to 2002 WRX fronts was that it was easier to lock up those wheels. I don't recall any notable change to pedal feel or travel and I heel and toe all the time.

[Legacy777]

Does your 90 wagon have ABS or no ABS? The ABS cars have the largest bore MC available, 1-1/16" dia.

When you bled the brakes, how did you bleed the brakes? What order did you go in, and what method? Proper order is RF, LR, LF, RR. When bleeding, I will typically slowly pump the brakes 10-20 times with firm pressure, hold on the last pump, have a helper open the bleeder valve for the affected wheel, (making sure to not leave the bleeder valve open so air enters the system. I will usually use a clear piece of tubing in a jar to watch for bubbles and make sure no air goes back in), then repeat for that wheel one to two more times, and then do the same for the other wheels.

Depending on how the brakes feel, I may repeat the entire process one to two more times. If you have ABS, it would be a good idea to activate the ABS system so any air trapped in it can move to the calipers. Once you activate the ABS, drive the car a little bit, and then bleed the brakes again.

SS braided lines will improve the pedal feel a little bit, but it won't be significant. The only thing that will significantly alter your pedal feel is swapping to the single diaphragm booster instead of the tandem diaphragm booster that comes stock.

The other thing to consider is if your master cylinder seals are worn, the feel may also be spongy. However, if the seals in the MC are worn, typically the pedal will slowly sink to the floor if you hold your foot on the brakes.

What Steve described is the biggest thing I noticed when switching to the WRX brakes, the fronts locked up much more easily.

[SWRT]

It's non-ABS.

When I bleed I always start with the furthest away from the master cylinder so I went RR, LR, RF, LF.
This time I had my dad at the caliper while I pumped the brakes. It'd build up a bit of pressure and
then release and we repeated that process. Is it possible that we just missed some air in the lines
this way?

I dont think it's the MC's seals. It doesnt tend to do that when I hold down the pedal. At least it didnt
before. I'll have to drive it tonight and make sure that's not happening. I didnt drive it around much
yesterday. Maybe 5 miles and I didnt hit many stops.

[Legacy777]

I suggest you repeat the bleeding process using the order I provided in my post. Make sure that when your bleeding to not allow any air back in the caliper. Pumping the brakes several times does help work the air bubbles to the caliper. If you want to increase the pressure, and I've had to do this before, start the car so you are using the vacuum assist of the booster. This will generate far more pressure in the system and hopefully push the air to the calipers.

The other thing i'll mention is that when upgrading to the WRX brakes on the non-abs cars I experienced excessive pedal travel compared to before. It's really annoying and makes the pedal feel worse than the already mushy Subaru brake pedal feel. This is due to the added volume requirements on the WRX calipers. I ended upgrading my MC to a 1-1/16" bore MC from an SVX. The non-abs MC's have 4-ports on them while the ABS cars have 2-ports. The non-ABS SVX is the only vehicle I found that uses a compatible master cylinder with 4-ports that will bolt on to our legacies. Finding a reman'd one from a parts store is probably your best best. Look in the 94-97 range, FWD only.

[SWRT]

Yeah, I had it running at the time, but I didnt do it the way I normally do which may be the reason it's not building adequate pressure. What is the reason behind the bleeding process if you dont mind me asking?

Dang, I'll definitely have to check that out. Is it a difficult thing changing out a master cylinder? I've never had to change one before.

Edit: I called Autozone and they said they only had one type for a 96 FWD and it didnt specify whether or not it was ABS. Do you have a picture of what I need to look for? I'm not really 100% sure what you mean when you refer to the ports. Is this on the side of the MC? I'd go look at mine for reference, but I'm at work and rode in with my brother in his Honda.

[Legacy777]

Under normal practice it has been to do the wheel furthest to the MC for one brake circuit and then the other, and then repeat with the additional brake circuit. When I say brake circuit, there is a primary and secondary brake circuit and each circuit controls diaganol wheels, Primary may control FL & RR, while the Secondary controls FR & RL. This way if you were to lose pressure in one circuit you could safely bring the vehicle to a stop.

Regarding why Subaru does things their way....don't know. They just do.

It's not difficult changing the MC, there's two 12mm nuts and you just remove the flare nuts holding the lines to the MC. It can be messy though. The tough part is bleeding everything after you've swapped the MC.

If it's for a FWD, it's like a 4-port MC. I do have some pictures, but apparently I'm having issues with internet connectivity on my server. I'll have to post the links when it comes back up.

[SWRT]

That seems logical enough. I'll have to give that a shot if I can find one of those MC's.
They didnt seem to know what I was talking about so I'll have to call around. Thanks, man!

[SWRT]

Would a used one be a bad idea?

[Legacy777]

Here are some pictures of a 2-port 1-1/16" bore MC. You can see the size on the casting for the MC.

http://www.main.experiencetherave.com/subaru/images/MC/

Here are pics of a disassembled MC, and you can see the two different brake circuits.

http://www.main.experiencetherave.com/s ... mastercyl/


As for a used one, no I don't think it'd be a big deal to get a used one. You can get a rebuild kit and replace the seals. As long as the inner bore is good and not etched/scratched, it'll be good to go.

[SWRT]

Since that is a two port they're both on the sides, but the 4 ports have two on the sides and two on the bottom, right? I see 4 lines running out of mine, so this is pretty much the stuff I'm looking for, I believe. Convenient that they happen to say 1 1/16th though.

[Legacy777]

Correct, two ports on the side and two on the bottom.

[SWRT]

Cool. Sorry for asking so many questions, but I'm cheap and didnt want to get the wrong thing. I'll start searching for one now! Thanks, man

[Legacy777]

Not a problem.....I'd definitely encourage folks to ask questions...that's the way you learn.

[SWRT]

Heck yeah! I've learned a lot about cars from my Subaru's and everything
that I can learn to do myself saves me money and gives me experience so
I dont tend to get too mad at problems with my car...unless it's like a trans
going out or something. That would suck.

I really appreciate all the help though. I'll be calling around here soon.
Going on vacation so it may have to wait til I get back.

[soobrdad02]

FWIW, it seems that the switch to stainless lines/hoses makes a significant difference. Also, Grimmspeed makes a bracket that fits the cylinder to help reduce the flex that causes the "squishy" feeling that our cars brakes are known for.

[Legacy777]

The brace does help, but it's not a dramatic change. Check out my thread with info on how much the brace helps. If you look at a comparison percentage, it does help pretty significantly, but if you look at the total amount of flex, it's not much.

http://bbs.legacycentral.org/viewtopic.php?f=11&t=2065