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This may have been asked on here before, and probably several times, but after a week of searching on here and nasioc, i cant find anything on the problem im having. I have a 99 Legacy L wagon, with an EJ22, and automatic trans, that i have been chasing a brake issue on for quite awhile now. I have replaced the front calipers and pads, rear rotors, pads, and calipers, and bled the brakes in the proper order at least 5 times, so i don't think air is an issue, but when im driving it, the pedal is soft when you first press it, and only stiffens up and works properly if you press the pedal, let up some, and press it again, then everything seems to work right. If the car is off, such as when it is sitting in my driveway, and i press the pedal, it drops maybe an inch and goes no further from the first press, and if i press it a couple times, it is so stiff it barely moves before it locks up, and doesn't drop no matter how long i hold the pedal for, but then when i start it, it goes right back to being soft again. So my question is, is there a definitive way to see if it is the booster, or master cylinder, or should i look for other issues?

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I did grease all of the caliper slide pins, and even the pad contact points front and rear, so i know it isn't a sticking caliper or pad. One thing i did notice when i did the front pads though, is that they were tight in the caliper mount on the one side, so i ground off some of the rust and crap on the mount so the pads would slide freely.

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Does the car have ABS? Some ABS systems have to be bled a certain way or you'll have air in the ABS unit that can cause a spongy pedal condition.

 

The are specs for testing the booster in the FSM I think. Basically check the amount of vacuum at the booster by putting a T adapter in the hose past the check valve. It should be the same as at the engine. Turn the engine off and vacuum should stay the same. If vacuum decreases the booster or check valve could be leaking.

With the engine running pump the pedal a few times then release. Turn the engine off. Push the pedal hard down and fully release at least 4 times until the pedal doesn't sink anymore, then hold. While still holding start the engine, the pedal should sink about 1-2". Pretty sure the spec for these cars is in the FSM.

If it passes that test, and is getting the proper source vacuum and holding it after the engine is turned off, the booster is good.

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Yes the car has ABS, but i have the FSM, and also checked what it said in their against what several people on different subaru sites have said, and i made sure i bled it each time the exact way the FSM stated. I have also checked the master cylinder, and have done all but the vacuum tests on the booster, and so far it all checks out, and im done putting parts on it that the FSM says could be bad, just to find out it doesnt fix the problem.

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I have always bled every ABS equipped subaru just like an older non-ABS subaru and have had no issues. I wouldn't think it's bleeding unless it needs bled because of some problem.

 

There is a valve somewhere in the vacuum line I think - maybe that is wonky? They freeze on some folks every winter and cause issues...I forget what.

 

Subaru master cylinder failure is very rare.....

 

On other cars folks would say one of your flexible brake lines at the wheel is failing and "expanding" internally - ballooning. Expands to a point then firms up....repeat when it contracts. They can also collapse. I've replace those hoses on other makes but never seen or heard of one failing on a Subaru. It would be one of the 4 flexible brake line hoses at each knuckle assembly.

 

I have seen rockauto have some crazy cheap brake hoses before....just cross reference the part number and make sure it's the right one.

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I would assume you probably would have noticed this since you've done all the brakes, but make sure non of the wheel bearings are loose.

If a wheel bearing is loose the first time you hit the brakes the caliper piston has to move farther to pull everything tight again and then when you hit them again everything is in place so the pedal is normal.

 

I've seen it before. There bearings don't always make noise when they are bad, and Subarus are pretty easy to bleed the brakes on without much trouble.

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We bought the car in january of this year, after it sat in a guys yard unmoving for 11 months, and i figured that the brake issue would be because everything was rusted or frozen, which is why i replaced and repaired the stuff i did, but the brake issue is still the same no matter what i do to it brake wise. The parts i replaced are as follows: Front pads, new semi mettallic, front calipers, rear calipers, pads and rotors, all about 5 months old, that i took from my other legacy that got wrecked in a walmart parking lot by an idiot, just after i finally had the car the way i wanted it.

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I would assume you probably would have noticed this since you've done all the brakes, but make sure non of the wheel bearings are loose.

If a wheel bearing is loose the first time you hit the brakes the caliper piston has to move farther to pull everything tight again and then when you hit them again everything is in place so the pedal is normal.

 

This isnt a one time issue, when you first start driving it, it happens every time you hit the brakes. It doesnt matter if it is every 50 feet, or every 200 miles, each time you hit the brakes, it always acts the same. I have checked wheel bearing, and all the front end components because it had a vibration we finally traced to a bad wheel, so i know nothing is wrong there. The only things i can think of it could possibly be, are the front rotors somehow causing it, or either a bad booster, master cylinder, or the front caliper mounts somehow screwed up from being rusted from sitting. I have just spent so much time on these brakes, and replaced so many parts, im starting to think it is just jinxed, so i figured before i messed with it again, i would see what the people on here had for ideas.

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There is a valve somewhere in the vacuum line I think - maybe that is wonky? They freeze on some folks every winter and cause issues...I forget what.

 

Thre is a valve in which vacuume line, the one to the booster? Mine is just a solid rubber hose from the intake to the booster, on both of my 99 legacy's.

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We have been driving it this way since about mid february. I was planning on leaving it at monro and just let them diagnose while we are out of town for the weekend, and take my other car, but now it seems that car is having trans issues, so we might have to take this one when we go, so i was just hoping to have an idea before saturday morning.

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I had a similar problem for the longest time. It took at least 3 months but the master cylinder went.

 

That is one of the things im leaning towards, mainly because even though i hear all the time they rarely fail, the car sat for quite awhile, and who knows what the P.O. did when they had the car, or even if the brakes were one of the issues he parked it for, since after i bought it, i found out he isnt exactly the honest type at all, i just dont want to spend the time and the money to do it, and have that not be it. The thing that sucks is, my outback's front brakes are different than the legacy's, so i cant just swap the mounts and rotors from one to the other and see if that changes anything.

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Thre is a valve in which vacuume line, the one to the booster? Mine is just a solid rubber hose from the intake to the booster, on both of my 99 legacy's.

 

There is a restrictor port in the booster hose something like midway. It's inside the hose, just looks like a little bulge in the hose about 1/2" long.

 

 

Id have to go with a bad master cylinder if you're sure you got all the air out of the lines. Brake fluid collects water, any moisture that might have got in the system while it was sitting for that long could have certainly caused the master to rust which would chew up the seals inside it.

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We may have found the problem, and i was wrong in one of my earlier posts. I had my brother check it at his shop, and he found that the drivers side wheel bearing is extremely loose, so he is gonna replace it in the morning, and see what happens. When i did all the brake work, i thought i checked it, but i may have overlooked it somehow.

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