Weird braking sound

[tyrel]

I hope someone has some ideas about my brakes. My brakes have been flawless up until a few months ago, when The Noise began. The left front brake makes this annoying grinding sound when I come to a complete stop, and when I wash the car, for instance when the rotor and pads get wet, there is a horrible groaning sound; it only makes this loud groaning sound when the pad is wet, after I drive for awhile the sound slowly disappears. I've never had this problem before. At first I thought it was a stuck caliper, so I changed out the caliper, the problem didn't go away. Then I figured it was time for new rotors and pads anyway so I changed them out as well (tirerack.com). New caliper, new rotor, new pads, and the sound is still there. Can't be the master cylinder or the brake booster, because then all the brakes would make the same sound. Flushed the brake lines AGAIN, sound is still there. I'm at my wit's end.

Can caliper mounting brackets bend? If so, that might explain it. Could it be a bad wheel bearing? The bearing seems fine. Didn't hit any potholes that I recall. Anyone have any ideas? TIA.

 

[Hrtbeat1]

Booster

My guess would be the brake booster. I sure hope its not though. Its a real PITA to get in and out. Just after I bought mine I thought I heard a groaning sound but it was real intermittent. I went to my relatives for Thanksgiving (about 470 miles), the next day I went to go somewhere and thought I didn't have brakes .... really scarry. The pedal went almost to the floor and then only under heavy brake pressure could I stop. Turns out it was the booster. On the underside near the battery it let go. I think I got the part from Autozone ... they had it in stock.

It was really cold when I got there and stayed that way the whole time I was there, and after a nice little trip like that may have had something to do with it.

Hey I get there Friday afternoon and got the whole weekend off. If ya want I'll help ya trouble shoot. I'm staying at the Ohana on Lewer's. Let me know.

 

[Hrtbeat1]

busted booster

This was the bad part.

 

[Vette_Newb]

I would suspect a wheel bearing from those symptoms.

Check it for play, up down / left right with the car jacked up.

 

[tyrel]

Hey Hrtbeat, thanks for the offer. I've replaced the booster before and know what a pain it is: remove the seat, lay on the floor, get poked in the back by the seat mounting bolts. Heh-heh, so irritating. Anyway, if it were the booster, wouldn't it affect all four brakes?

Vette_newb, I thought it might be the wheel bearing as well but couldn't be sure. It would make sense, however, since some play in the bearing would throw off the orientation of the rotor and cause it to vibrate. There's literally nothing else it could be.

Thanks dudes.

 

[tyrel]

Just checked my wheel bearings on both front wheels and they are tight as a drum. Any other ideas? Anyone?

 

[Vette_Newb]

At this point in the game, the only thing you haven't changed is the hub/bearing. I would change it since that is the last moving part involved, and if it's original from 1989 it could not hurt.

 

[Hrtbeat1]

Next guess

What is the condition of your hose? I see you flushed the lines again but how's the little section from the line to the caliper? Just a thought. I think it could possibly be something with the master or booster, and not effecting the other wheels. The front left is the closest to the master cylinder and if the pressure is excessive, that would be the first to "feel it."

Something else try tapping on the sides of the caliper with a wrench and try bleeding them again. There may be a trapped air bubble. Dunno' grabbing for anything here.:confused

Offer still stands

 

[tyrel]

Thanks guys.

I hate to throw money at the problem, but the only thing left is the wheel bearing since I checked everything else: hoses, master cylinder, brake booster, everything. These parts are all new within the last year. There is literally nothing left but the wheel bearing. I'll change it out tomorrow or Thursday and report back here, the info might be useful for future reference for others who have this problem.

 

[cntrhub]

You didn't mention anything about having anti-seize behind the brake pads? Could this be a simple vibration at low speeds? Before you throw money at it, try this. If you did use anti-seize or equivalent for pad chatter, have the hub bearings ever been replaced? Can you see dirt build up behind the hub assembly? This my show the seal is worn and there may be a bearing failure in the making?

 

[4U2NV1986]

I would guess the wheel bearing. The obvious would be to check for slop in the hub assembly, but bearing issues are hard to diagnose because when bearing are checked they are typically never under the full weight of the car. What may feel fine off the ground may in fact under load have issues. Additionally, some cross drilled rotors will kinda grind at slower speeds. Not a metal to metal grind, but you can feel it in the pedal. Good luck!