Title says it all and the brakes are not wet. Usually occurs after 20 min of driving I can hear a low hum like a foghorn from the front only while applying pressure. No squeeks just foghorn like. Master cylinder just replaced and no pedal dive. Brakes don't feel as resposive as they used to and while braking I do feel vibrations in the wheel. Rotors and pads...hmmmm I think about 2.5 years old or so.

Best,
Adam
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'92 244GL silver-metallic, 150k, Enem V15 cam, Bilstein HDs, IPD sways, upper+lower braces, Cherry-Turbo strut brace, 240 OEM rear spoiler, 15' Dracos, E-codes w/side repeaters, Euro cowl covers paint-matched, Magnaflow 2.5' SS exhaust w/Unitek header

Thanks guys for the suggestions. I'll try to tackle them this weekend.

Best,
-Adam
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'92 244GL silver-metallic, 150k, Enem V15 cam, Bilstein HDs, IPD sways, upper+lower braces, Cherry-Turbo strut brace, 240 OEM rear spoiler, 15' Dracos, E-codes w/side repeaters, Euro cowl covers paint-matched, Magnaflow 2.5' SS exhaust w/Unitek header

Just had this same problem on a 93 Camry that was caused by a worn/shrunken control arm bushing. When the brakes were applied, it loaded the rear of the arm and it vibrated. Sounded just like you describe, a fog horn.

Inspect all the brakes carefully- I'm thinking you have a stuck caliper or something, and may have completely worn out pads on the inside of one rotor. You could just be starting to go metal-to-metal.
If they all turn out to be ok, then I'd try redoing the shims and pad silicone grease. If that still won't fix it, try a softer pad- the Volvo pads are a bit more but the kit does come with the shims, so it's worth it.

Good luck!
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Rob Bareiss, New London CT ::: '87 244DL/M47- 230K, 88 744GLE- 220K, 82 245T-181K Also responsible for the care and feeding of: 88 745GLE, 231K, 87 244DL, 239K, 94 855GLT 189K

I had a similar sound for a while on my 1986 244. Low brake pressure, not much variation with time of day, or if first or later start. The sound was amazingly loud.

Sounded to me like a worn down brake pad was vibrating on the rotor in a frequency that resonated with the natural frequency of the coil spring. Later when the pads were replaced the sound went away.

Check the pads - that's my only guess.

Good Luck,

Bob

:>)