spongy brakes

Bleed the brakes better?

Bleed the brakes better?

I had owned my subie for about 6 years before I finally flushed the fluid, and expected to get much better brake feel. I didn't. I actually got a softer pedal just like you. I figured out why though. At least in my case. I used a vacuum pump to bleed them. I am not sure if the tubing I used was too large, or if I had loosened the bleedscrews too much, but for some reason I was getting lots of air in the tubing. I assumed it was a leaky seal at the tubing/bleeder interface, which I wouldn't think woudl create any problem. I finished upa nd tested thepedal and it was soft. I them theorized that perhaps the air was coming in around the bleed screw and a little air remained just behind the bleed screw. So I went with an old method I used to use, and put a piece of tubing into a jar of brake fluid and stomped on the brakes hard, and slowly let them up. This forced the air bubbles out, and since the pedal was returnig slowly, it wasn't pulling fluid in that quickly, and thus didn't have the vacuum present to cause air to come in around that seal of the tubing on the bleedscrew. It worked.

If you have time, gravity draining works in these cars too. Just get four lengths of tubing and four receptacles. Put the car on jackstands and attach the tubing, loosen the screws, and every few minutes top off the fluid at the master cylinder. Don't let it run dry.

Good luck

If it has rear drum brakes, the rear brakes could be in need of adjustment, indicating the self-adjusters have seized, you never back up, or they are worn out.

Does pumping the pedal help?

Does the pedal slowly sink if you keep constant firm pressure on it?

If the pedal is low but not spongy, that could be the pedal being out of adjustment- some of these come with an adjustable rod goung to the brake pedal.

Dave

It seems unlikely an 03 would have a problem with the rubber lines, but new (or even better stainless steel braided) brake lines can help with sponginess/and/or restore a 'like new' brake feel.

Best to make certain there is no air in the lines. With ABS equipment, it can be trickier to bleed the system I think.

good luck

Carl

Update:

I'm starting to think my wife was complaining about the ABS kicking in. Tonight was rainy, and the ABS was kicking in just about everytime I hit the brakes. Annoying. I remember feeling annoyed about the ABS when the car was new. Perhaps the new fluid is less spongy, and the drivers are simply not used to the new fluid. It is pretty bad tho, almost dangerous. I'll test it out again when it's not so wet.

Other option: Master Cylinder. I found this article somewhere (lost it now) that explained a possible cause when a brake fluid change is followed by low pedal after a few days. Goes like this: Old fluid has moisture in it. Eventually the seals absorb moisture too. If everything happens gradually, nothing dramatic happens. After a long time, new fluid goes in. Fairly quickly, the "moist" seals "donate" moisture to the new fluid. Seal shape changes, and does not provide a good seal anymore. No leaking, (since the "leak" happens inside the cylinder) but poor performance.

The brakes felt weak and squishy one day, but they seem OK now. I don't know if the seals just had to settle down or something. But the ABS thing was really annoying tonight, and it may explain my wife's experience.

So I'll give it a few more days before going back to the shop.

Hmmm...now that I think about it...didn't some soobs get an ABS system 'reflash' or recall? wait...

well, they don't mention the OBS but i found this at cars101.com;

******Satisfaction program 06-35-05R. this is not a recall. A response to concerns about ABS performance on 2002-03 WRX 5spd of a feeling of a delayed response when ABS is activated during inital braking over bumps, potholes or other low friction road surfaces. With assistance from Subaru, NHTSA conducted over 11,500 tests to investigate this report and while NHTSA and Subaru did not indentify a problem that would require a recall, they did identify a certain ABS performance characteristic that might cause some driver's to identify a delayed response feel during the first second of braking. Following this analysis, Subaru developed an alternative method of calibrating the ABS to address this performance characteristic.No perceptible improvement in overall stopping difference will result. If the driver of an affected vehicle encounters this set of conditions and is uncomfortable, a complimentary ABS with different calibration is available. This is not mandatory, rather this service is being offered to enhance customer satisfation. Only some owners will experience this ABS characteristic and SoA will contact owners of eligible vehicles by mail through October 2005.******

Carl

Still have the stock potenzas on there?

Dave

At 190,000kms, THAT would be impressive!

Crappy winters are still on the car. Not enough thread for another winter so I've not been motivated to swap them yet.

Hmmm, very interesting. The term "delayed response" has me nodding my head. When the ABS decides to kick in, the first thing that happens is that the brake system pressure seems to drop like a rock. Pedal heads towards the floor, and car stops slowing down, almost to the point where it feels like i.t is actually speeding up. After a brief moment (which could be the "delayed response,") the car starts to slow down in an ABS-controlled manner. Somebody who didn't care much to understand how stuff works would probably describe it as "delayed response."

Mine is not a WRX, but rather an OBS. Same system? I wonder if I can try this "alternate calibration." I'll mention it to the dealer see if they have any clue. I've always felt the ABS kicked in unreasonably early. Are newer systems better?

This is a long shot, but my ABS kept kicking in when I turned in one direction with the brakes on. I forget which direction, but it doesn't matter. The problem turned out to be a bad wheel bearing on the outside rear wheel. The load on that wheel combined with the bad wheel bearing would cause the wheel to kind of steer, which let the speed ring get far enough away from the ABS wheel speed sensor, and that wheel got cut brake pressure. Is it possible that you have something affecting the sensors? Long shot, but just tossing stuff out there to mull over.

Mine feel like crap too. The pads rotors are aftermarket but apparently high end.

Are yours aftermarket too?

Same deal--it feels so lousy I want to think there's a bubble in the brake line but themechanic swears up and down it's been bled, burped, and all that and the pads are just squishy.

-- Todd H.

2001 Legacy Outback Wagon, 2.5L H-4 Chicago, Illinois USA

The aftermarket pads (wagner) I put on my wife's Outback are noticeably inferior to the original pads. I'm going back to OEM on her car - and will soon need pads on my car - I'm 'probably' going with OEM. I MIGHT consider EBC yellow.

Carl

Yes, I did replace everything about a year ago. I hadn't thought of that fact. I always read so much about sticking with stock pads, but I wasn't that close to a dealer at the time. In the end, I had to run to the dealer at the last minute cause I broke a caliper bolt and could not find the right bolt anywhere locally. I hope I never have to replace the rotors and drums again because the new ones I got don't have the bolt holes to push out against the flange and un-seize them ...

I just ran across something that might be contributing to this.

Some replacement pads have the metal backing made too large, and the pad hangs up in the slots the pad slides in.

If you have just one hung pad that bending or bowing even a tiny amount when the brakes are applied, that would give you spongy brakes.

I just did rear pads and rotors, and had to be pretty forceful to get the rear pads out, and I could have hammered the new ones in but instead elected to trim the backing plates with the grinder- just enough, and in just the right places.

Dave

I hammered pads in once on a volvo wagon. Big Mistake. They bound up in the housing, and once I applied my brakes, they got stuck there. Then they were stuck in the applied position. It was apparenlty not enough to apply a significant braking force because I didn't notice it. However, the pad heated up enough that I had smoke pouring off that corner of my car. I noticed that and went to slow down to pull over and my brake pedal hit the floor. Apparently I had boiled the fluid. I got the car stopped and let it cool off, then I had brakes. That was quite scary though.

This is at least my mechanic's idea of what happened. He also added on that I should have used OEM pads. Since then I have always run the ends of pads over a rough asphalt surface to grind off a little before putting them in. That's how I get around his recommendation. It's usually just a thick layer of paint that comes off, but I have never had the problem again.

Bill