So I went for a test run today with my new to me 99 Ram 4X4
Just a short run around the Foothills, all road driving.
I start the drive home, mostly downhill but not steep, just barely useing the brakes and they start cooking after only a mile or so down.
They were Cooking, smoke was coming of them. Let them cool and start again, I can't even go 1/4 mile down hill lightly useing them and they start cooking.
The Calipers are Not sticking, the pads are 3/4 or better, the discs are not grooved.
What the Heck is going on ?
Only thing I can remotly come up with is possibly the back brakes not working at all. Tires are 265/75R16, so over sized tires are not an issue
HELP !

 

How are you sure the calipers aren't sticking? Only real way to tell, is jack up the front, and try and spin them by hand.

Is the brake lite in the dash on? I would take a look at all the rear lines, and verify their condition. May not hurt to adjust up the rears either......

 

Jacked up the front and took the wheel off, I can spin the hub with one finger. No brake light.
Will adjust and test rears tomorrow

 

Are your rotors getting thin?

 

No idea
I'll have to find out what they are suppose to be, maybe the previous owner had them turned to much at one point.
Going to tear into the whole system tomorrow.

Funny thing, when I drove the truck home the other day when I bought it, I had a lot of down hill braking and they never got hot.

 

Spitballin' here.

I second the check on rotor thickness spec. Couple other things to check out as I would and that would be:

1. if they are the "right" pads. that requires pulling them out I think, but not sure if they have identification marks. Might be worth just getting replacement pads from Napa. Just some cheapies to rule out pads? I know that might be wasted money, but its an acceptable risk regarding ability to stop.

2. Brake master cylinder health. I wonder if the piston is binding? Maybe even give a look at vacuum boost? I've got no experience with these things, but seems worth checking out given their contributing relationship to the system.


Assumptions are that both wheels spin fine based on your report above, no leaking brake fluid, brake fluid level is correct, etc.

Worth asking the PO on the brake history??? Oh...and both brakes heat up or just one side?

 

Maybe that's the problem to begin with.

 

Just finished checking over everything.

Fronts;
Rotors spin free by hand and look fine, Measure 1.290, no cracks and
no heat spots.
Calipers compress easily, no leaks
Pads are New

Rear;
Pads are atleast 3/4, all hardware looks fairly new
Drums are fine
Adjusters work properly
Slaves work properly and no leaks

Like Zman17 say's, I'm wondering if the pads are just cheap crap.

 

Minimum thickness for turning rotors SHOULD be stamped on rotors. I cannot remember what it should be. Manual refers to stamp on rotor - catch 22.

Aftermarket rotors may not be stamped unless it it mandated by DOT or someone...

I would check rotor for runout as well. Heat will tens to warp them and cause a pulsation on braking.

I prefer the ceramic pads as they create less heat, effective stopping, and less dust.

 

Could be a proportioning valve too?