RyanE Posted April 5, 2007 Share Posted April 5, 2007 Hi folks, So I flushed my brakes at 30,000 miles along with the rest of the 30k routine, and was rewarded with a much firmer brake pedal. The same thing happened at 15k miles when I flushed my brakes, and both times I had no bubbles come out from any of the corners. I have bled brakes many many many times before, and like to think I know what I am doing, so I was very puzzled when my pedal travel increased now that there's 200ish miles since the 30k brake fluid flush. I noticed that "double-pumping" the brake pedal will firm it up, which normally means air in the lines, but like I said, lots of bleeding/flushing, no air came out, and the pedal was firm for the first 200ish miles after the bleed/flush. My though is that if I'm losing a wheel bearing, the rotor is wobbling and causing some kickback against the pads, moving them away from the rotor(s) and causing longer pedal travel. I've dealt with this before on other vehicles. I can't really hear any bad bearings, but I do have a high pitched noise that sounds somewhat like a turbo spooling at 60-80 mph (car is stock), and there's enough other rattles in the car to make it hard to tell. Any thoughts would be appreciated, and thanks for reading this giant post. -Ryan Link to comment Share on other sites More sharing options...
AWDxBOOST Posted April 5, 2007 Share Posted April 5, 2007 i doubt its bad wheel bearings...that would be very noticable up to speed. bad rotors would make the whole car shake under moderate to hard braking. by double pump, you mean pump your brakes when at a stop or something? every car ive ever done that on, the pedal firms up a lot...that is normal as for the high pitched noise, couldnt tell ya without hearing it. Link to comment Share on other sites More sharing options...
lvethesnow Posted April 5, 2007 Share Posted April 5, 2007 from my experience the high pitch noise is the break wear indicator. its a small metal clip attached to pads so that when your breaks get to worn out it rubs againsts the rotor to let you know it time to change the pads. the clip is removable when you change your pads. if you want to get rid of them History does not entrust the care of freedom to the weak or timid People sleep peacefully at night cause rough men stand ready to do violence on there behalf Link to comment Share on other sites More sharing options...
RyanE Posted April 5, 2007 Author Share Posted April 5, 2007 I get the high pitched noise just cruising on the highway - no brakes being applied. It's almost like a whistle, so I guess it could be just the wastegate dumping or something. Car doesn't shake under braking, so I don't think they're warped. I had the rears replaced under warranty due to excessive surface scoring, but no warping. As for the double pump, I know what you're saying about most cars getting harder when you double pump, it's just that it went from "pump-firm, pump-firmer" to "pump-not so firm, pump-firm." I dunno. I guess I have to shake the heck out of the wheels again, but I gotta say that I agree that I should be hearing some kind of bearing noise at speed. Frustrating!!! Thanks for the suggestions - I'll keep investigating. -Ryan Link to comment Share on other sites More sharing options...
AWDxBOOST Posted April 5, 2007 Share Posted April 5, 2007 maybe try bleeding one more time just for the hell of it? i doubt the seals in the master cylinder went bad, but it could happen i suppose id say do that and double check all the calipers to make sure the pad is seated properly in them and that everything is tight Link to comment Share on other sites More sharing options...
one69chev Posted April 6, 2007 Share Posted April 6, 2007 some manufacturers will but a metal tang on the brake pad backing so that when the pads get low enough, the little metal do-floppy makes contact with the rotor. and that will make a squealing noise to let the driver know that the pads are worn. your wheel bearings are not part of the brake hydrualic system, so no amount of bleeding/pedal pumping with affect them. when my olds' wheel bearing crapped out at 40k, it sounds like i had a swarm of bees in my tire when driven at 35-50 mph. when i turned to the right, it got louder, indicating that the pass side bearing was shot. r&r the bearing, no problem. low front pads could result in excess pedal travel; and air in the system will feel spongey. let us know what you find....... Link to comment Share on other sites More sharing options...
RyanE Posted April 6, 2007 Author Share Posted April 6, 2007 I have plenty of pad life left, so I don't think that's the problem. The reason I though of the wheel bearings is that I've had cars with bad bearings in the past that make the wheel "wobble," causing the rotor to push the pads slightly away, leading to a lower pedal due to the farther distance the pads have to move to fully contact the rotor. Normally, however, you can hear those bearings a mile away, and I have no such noise. I've been doing left and right turns in parking lots to try and isolate any noise, but no such luck. I bled the hell out of the brakes to eliminate air in the lines as a possible problem - I understand that the wheel bearings are not part of the hydraulic system. I think I'll let the dealership deal with it if shaking the hell out of the wheels and checking the pads one more time doesn't turn up anything. We went from 70 degrees F to 25 degrees F in one day here in Michigan, so I haven't been out in the garage again to check. I'll keep you folks posted, and thanks again for the suggestions. -Ryan Link to comment Share on other sites More sharing options...
Beanboy Posted April 6, 2007 Share Posted April 6, 2007 From my little experience with Subaru wheel bearings, they won't wobble, even if they are on their way out. Even with axle nut loosened and then wheel shaken, still won't wobble. Just noise above 40mph, or if you get the car up on the lift and wheels spinning. Once hub is off and you try to spin them, you can most certainly feel the bad one. My case it was passenger rear, although I think I have more going. As far as brake feel goes, how about water? Mine are up for a bleeding soon since I'm getting a little too much "Buick" feel in the brake pedal, although even bled with SS lines I think the LGT brakes feel too soft. -B http://www.standardshift.com Link to comment Share on other sites More sharing options...
G.T.Subie Posted April 6, 2007 Share Posted April 6, 2007 I have noticed the same thing as the OP. I have SS lines Motul fluid and Bobcats, I still double pump the brakes everytime to get a firmer feel on the pedal. At this point I am used to it. Denial is your best friend Link to comment Share on other sites More sharing options...
bugblatterbeast Posted April 6, 2007 Share Posted April 6, 2007 Hi folks, I noticed that "double-pumping" the brake pedal will firm it up, -Ryan probably your shims. mine were a little warped and knocked back the piston given enough time. a quick double pump would get them to stick flat and firm up the pedal. with them out the pedal feels the same with every application. I had the same problem with the Acura and my parent's hondas. If you can put up with a little noise, just toss the shims. Link to comment Share on other sites More sharing options...
RyanE Posted April 7, 2007 Author Share Posted April 7, 2007 That's good info about the wheel bearings not wobbling - I'll try without the shims as well. Time to break (brake?) out the CRC no squeak... Thanks guys, Ryan Link to comment Share on other sites More sharing options...
fedaykin Posted March 3, 2016 Share Posted March 3, 2016 I wonder if it's a feature? Soft initial pedal but firm second one? Or maybe master needs new seals? Link to comment Share on other sites More sharing options...
DonnyJagaru Posted March 4, 2016 Share Posted March 4, 2016 I think this is normal for our cars. I did a complete brake swap and bleed (in the right order as per Sub manual) and tightened up the pedal. Now a year or so into it there is a little play on the first pump. I don't think its air, I think its a combination of pad wear and piston travel. I suppose if the brake master cylinder moved more volume we wouldn't be having this conversation. Link to comment Share on other sites More sharing options...
MaStaMooN Posted August 1, 2016 Share Posted August 1, 2016 I bet piston is sticking. Sent from my Nexus 6 using Tapatalk Jon - vBGarage Profile Link to comment Share on other sites More sharing options...
quick4dr Posted August 1, 2016 Share Posted August 1, 2016 two new calipers on front, no vibration or shimmy. I have the phenomenon as well that double pump firms it up. and that's with stainless lines, blue fluid, grimmspeed brace. maybe master starting to fail? Link to comment Share on other sites More sharing options...
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