Strange brake noise, hot front brakes

screamin gt

5 Year Member
Apr 9, 2007
394
6
28
central CT
Recently having some trouble on my 99 GT. Stock calipers, SS brake lines, has drilled slotted rotors but just changed back to regular. Brakes were getting very hot in front to the point that it was dragging and I would have to get on it to be able to go almost like fronts were locked up. Using infra red gun temps were close to 500 on the fronts and only 130 on the rears. Once they heated up like that I got a crazy shake like warped rotors even with the slightest touch of the pedal.

Thought the calipers were sticking but the pistons are in like new shape. Once car was jacked up it was somewhat difficult to spin the fronts but I really don't think the problem is with the calipers. The ss lines are only about 5 years old.

Drove like a new car for a short test drive yesterday after replacing the rotors with standard ones. Although I haven't driven long enough to let them get hot yet, brakes seem to function normal.

When I parked though I noticed hitting the brakes caused a pump type of sound something like a power steering pump noise. Quite loud and I've never heard this before in my 12 years owning the car. It also vibrates somewhat matching the pump noise. Not really sure how to explain that.

Need some help with this.
 
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Mustang5L5

i'm familiar with penetration
Mod Dude
Feb 18, 2001
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The 99-04 GT front calipers are notorious for sticking, especially when the car has sat for a period of time.

when the brakes are hot and appeared locked up, can you jack up a wheel and spin it?
 

screamin gt

5 Year Member
Apr 9, 2007
394
6
28
central CT
The 99-04 GT front calipers are notorious for sticking, especially when the car has sat for a period of time.

when the brakes are hot and appeared locked up, can you jack up a wheel and spin it?
Such a pain to jack this car up. Have to drive it up on 2x6 to get high enough for a jack and then find a way to avoid dimples in my asphault. But I guess I'll have to do this tomorrow.
 

stormsedge

Active Member
Jun 17, 2018
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Such a pain to jack this car up. Have to drive it up on 2x6 to get high enough for a jack and then find a way to avoid dimples in my asphault. But I guess I'll have to do this tomorrow.

I've had good luck protecting asphalt from my jacks by placing plywood/scrap wood under the jack. Some ideas on the brakes:

Did you rebuild the calipers or just do a visual on the pistons exposed beyond the boots/seals? If no rebuild, note that the interior of the caliper may be mucked up and/or the pistons have developed a ridge on them preventing proper extension/return.

The sliding surfaces and/or guide pins on your calipers may be mucked up (sometimes the pins develop rough spots or ridges that prevent proper operation as well.
 

screamin gt

5 Year Member
Apr 9, 2007
394
6
28
central CT
I've had good luck protecting asphalt from my jacks by placing plywood/scrap wood under the jack. Some ideas on the brakes:

Did you rebuild the calipers or just do a visual on the pistons exposed beyond the boots/seals? If no rebuild, note that the interior of the caliper may be mucked up and/or the pistons have developed a ridge on them preventing proper extension/return.

The sliding surfaces and/or guide pins on your calipers may be mucked up (sometimes the pins develop rough spots or ridges that prevent proper operation as well.
So I did rebuild them about 4 or 5 years ago.
Drove it today about a half hour and seemed fine. Began t storms just as I got back home so I skipped jacking it up. Temps on both front rotors were 350 to 400 hottest being at the edge of the rotor.

I decided to go ahead and get a set of the cobra calipers and rotors. I'm thinking I'll just hang onto to them for a while and swap them out if there's further issues. I'll have to clean them up and paint them to match anyway.
 
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weendoggy

Member
Jan 14, 2019
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One big item I hardly ever see on this topic (brakes) is the hose itself. If you have the stock rubber hoses, they may look good on the outside, but it's the inside that causes the problems. They deteriorate on the inside more than you think. This will cause the fluid (under pressure) to get to the caliper, but when it's time to retreat....it can't because the hose has restricted flow. Now, I"m not saying this IS the cause, just something to consider. Especially if you've either rebuilt or replaced calipers and especially an older or high mileage car.

This is one of the first things I do on my older cars I've purchased or built. I use a teflon lined SS braided hose.