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Discussion Starter #1
My problem began a couple of weeks ago when I followed the procedure in the haynes manual for adjusting brake pedal travel. I thought it was too much. When I got done adjusting it I went for a test drive and when I got back the front brake pads were smoking. I adjusted the pedal back to where it was but the front rotors still get awfully hot. Since that time I have:

Dismantled and cleaned both front calipers and installed repair kits.

Pulled master cylinder off, pulled vacuum booster off and checked push rod and operating rod lengths. (both were within spec.)

Replaced master cylinder with rebuilt.

Dismantled and cleaned Neutral Pressure valve.

Bled brakes. (I've completely changed the brake fluid)

Removed calipers and pads, greased appropriate caliper areas, (according the the manual) and reassembled.

With the wheels off the ground they appear to spin freely enough, I don't really notice any brake drag. Yet even driving distances of less than 3 miles at 30-35 mph when I stop the car the rear rotors are a little warm to the touch and the front rotors are hot enough you can't hold your finger on them. (The front hubs and calipers are not hot, unless I drive a lot further)

Any solutions?

Thanks in advance!

Bob A.
 

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> My problem began a couple of weeks ago when
> I followed the procedure in the haynes
> manual for adjusting brake pedal travel. I
> thought it was too much. When I got done
> adjusting it I went for a test drive and
> when I got back the front brake pads were
> smoking. I adjusted the pedal back to where
> it was but the front rotors still get
> awfully hot. Since that time I have:

> Dismantled and cleaned both front calipers
> and installed repair kits.

> Pulled master cylinder off, pulled vacuum
> booster off and checked push rod and
> operating rod lengths. (both were within
> spec.)

> Replaced master cylinder with rebuilt.

> Dismantled and cleaned Neutral Pressure
> valve.

> Bled brakes. (I've completely changed the
> brake fluid)

> Removed calipers and pads, greased
> appropriate caliper areas, (according the
> the manual) and reassembled.

> With the wheels off the ground they appear
> to spin freely enough, I don't really notice
> any brake drag. Yet even driving distances
> of less than 3 miles at 30-35 mph when I
> stop the car the rear rotors are a little
> warm to the touch and the front rotors are
> hot enough you can't hold your finger on
> them. (The front hubs and calipers are not
> hot, unless I drive a lot further)

> Any solutions?

> Thanks in advance!

> Bob A.
DONT force your pads to break in to fast!
did you check your rear shoes? that was always
my my pedal travel ploblem. GRease your rear adjusters also.I also hope you did not contaminate
your pads or glaze them from hard braking and excessive handling of them between repairs it only takes one drop of brake fluid.Z cars also
always had afade/heat problem .Even with new fronts complete pads calipers hardware dot 5 fluid
still had excessive travel.It was all linked to
replacement and adjustment of the rear shoes.
Also drilled rotors and dot5 help the fade problem
hope this info helped JIM in CHICAGO
 

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> With the wheels off the ground they appear
> to spin freely enough, I don't really notice
> any brake drag. Yet even driving distances
> of less than 3 miles at 30-35 mph when I
> stop the car the rear rotors are a little
> warm to the touch and the front rotors are
> hot enough you can't hold your finger on
> them. (The front hubs and calipers are not
> hot, unless I drive a lot further)

> Any solutions?

The rotors are SUPPOSED to get hot. That heat is where the kinetic energy of the car goes why you slow it down by braking! :^)

Typical operating temperatures on the rear calipers are in the broad range around 200 degrees Fahrenheit, and the front rotors around 300 degrees ( if I'm driving very conservatively. ) Of course this varies alot depending on how much use the brakes are getting while you're driving.

I certainly wouldn't expect to touch any of them with my fingers!!!

You have inadvertently oversensitized yourself to something which is in fact normal. It could happen to any of us.

Doug Dawson
[email protected]
 

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> The rotors are SUPPOSED to get hot. That
> heat is where the kinetic energy of the car
> goes why you slow it down by braking! :^)
[shouldbe]WHEN you slow it down by braking :^b

> Typical operating temperatures on the rear
> calipers
I meant on the rear ROTORS, you don't want your calipers to get as hot as the rotors
> are in the broad range around 200
> degrees Fahrenheit, and the front rotors
> around 300 degrees ( if I'm driving very
> conservatively. ) Of course this varies alot
> depending on how much use the brakes are
> getting while you're driving.

That's what I get when I post before my first morning coffee!

Doug Dawson
[email protected]
 

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Discussion Starter #5
Thanks Doug!

I was hoping that someone would tell me this was normal. I realized that the rotors should get hot from braking. But I was concerned that on short stop and go trips (low speed, stopped a lot, less than 3 miles) that they were getting way hotter than they should. This made me wary of trying to get out and run with it for fear of smoking them.

Bob A.

> [shouldbe]WHEN you slow it down by braking
> :^b
> I meant on the rear ROTORS, you don't want
> your calipers to get as hot as the rotors

> That's what I get when I post before my
> first morning coffee!

> Doug Dawson
> [email protected]
 

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Discussion Starter #6
Actually my complaint isn't about poor braking performance, they seem to work fine except maybe a little too much pedal travel. Just concerned that they are getting a lot hotter than they should on short trips at low speed and minimal braking.

Thanks for taking the time to respond!

Bob A.

> DONT force your pads to break in to fast!
> did you check your rear shoes? that was
> always
> my my pedal travel ploblem. GRease your rear
> adjusters also.I also hope you did not
> contaminate
> your pads or glaze them from hard braking
> and excessive handling of them between
> repairs it only takes one drop of brake
> fluid.Z cars also
> always had afade/heat problem .Even with new
> fronts complete pads calipers hardware dot 5
> fluid
> still had excessive travel.It was all linked
> to
> replacement and adjustment of the rear
> shoes.
> Also drilled rotors and dot5 help the fade
> problem
> hope this info helped JIM in CHICAGO
 

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> Thanks Doug!

> I was hoping that someone would tell me this
> was normal. I realized that the rotors
> should get hot from braking. But I was
> concerned that on short stop and go trips
> (low speed, stopped a lot, less than 3
> miles) that they were getting way hotter
> than they should. This made me wary of
> trying to get out and run with it for fear
> of smoking them.

A short trip in city traffic of maybe 3 miles results in a rear rotor temperature in the low 1xx degrees for the rear and the upper 1xx degrees for the front rotors, on my '83, if I drive normally.

BTW, these temperature readings are taken with a laser-guided infrared remote pyrometer, which I keep in the car at all times, mainly for purposes of wheel camber adjustment and tire temperature readings.

Doug Dawson
[email protected]
 

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Discussion Starter #8
Unfortunately, some of us have to make do with calibrated fingertips.

The good news is that I got out and ran it about 10 miles at 45-50 mph and when I stopped the car the wheels, rotors, and calipers were all cool. I then drove around town for 4-5 miles at 30-40 mph and when I parked in my driveway the wheels and calipers were cool but the rotors were hot.

So... I'm relieved to think that it is normal.

Thanks for your help!

Bob A.

> A short trip in city traffic of maybe 3
> miles results in a rear rotor temperature in
> the low 1xx degrees for the rear and the
> upper 1xx degrees for the front rotors, on
> my '83, if I drive normally.

> BTW, these temperature readings are taken
> with a laser-guided infrared remote
> pyrometer, which I keep in the car at all
> times, mainly for purposes of wheel camber
> adjustment and tire temperature readings.

> Doug Dawson
> [email protected]
 

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> Unfortunately, some of us have to make do
> with calibrated fingertips.

> The good news is that I got out and ran it
> about 10 miles at 45-50 mph and when I
> stopped the car the wheels, rotors, and
> calipers were all cool. I then drove around
> town for 4-5 miles at 30-40 mph and when I
> parked in my driveway the wheels and
> calipers were cool but the rotors were hot.

> So... I'm relieved to think that it is
> normal.

> Thanks for your help!

> Bob A.
I wouldnt worry about it either .
My pedal travel problem is gone .
But the brakes still get hot i dont need a physics
engineer to tell me that is normal.It always depends on air temp and driving habits.Try keeping
any brakes cool that are bringing your car down
from 140 MPH ! You want to talk about kinetic energy and smoking parts thats what the dot 5 is for.very high boiling point and no expansion.
Good for spirited driving.
 
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