Rebuilding brakes - consensus on when?

[JBurer]

I'm getting ready to replace brake pads on my '91 Turbo. Is there any rule of thumb (years or miles?) on when the brakes need to be rebuilt?
Thanks,
John

[RWebb]

define "rebuild"

replace the pads when they are worn

replace rotors when uneven (check runout etc. with dial indicator) or just replace when you do the pads

replace brake fluid every 2 years

replace rubber brake hoses with new ones every 10-20 years

[mpetry]

Bill V. is the brake expert so I'm sure he'll jump in, but here's my thought. Consider that your car is 20 years old, so of course you're going to replace pads, inspect the rotors and replace them if there's the slightest sign of ridges, scoring, or runout.

I would recommend you absolutely replace the rubber flex lines with stainless steel flex lines. You'll find that this step alone improves the pedal feel.

As an option, consider having the calipers rebuilt. I have used Goldline Brake in Seattle, he does a fantastic job and the calipers come back better than new.

Then completely purge the fluid, preferably using a pressure bleeder rather than pumping the pedal. There are some reports of the master cylinder being damaged by pushing the piston past the worn area and compromizing the seal. One could argue that such a master cylinder was marginal anyway, so make of that what you will.

Last thing - after it's all done, don't go out and dynamite the brakes first time out. Opinions vary, but best practice is to go thru a break in process that involves using the brakes gently for 100 miles or so, then doing several heat cycles with progressively harder braking, to get the pads properly bedded in.

[Flieger]

Go hard on the brakes right away. Otherwise, during that gentle 100 miles you will have wooden brakes and not be able to stop. It might even glaze the pads and prevent proper bedding in later.

I followed this process: New Pad Bedding/Break-In
and added the several 80-5 stops for the aggressive street pads (Porterfield R4S).

When you smell them, you know you have done it right.


As for when to rebuild, if stopping distances are excessive, the car pulls under braking, locks a particular wheel consistantly more than others, or if one wheel well feels hotter than the others, those are signs that a rebuild is in order. If you remove the wheel and pads and try to push the pistons back in. If you cannot push them in or out, then they are "frozen" and need rebuilding.

[JBurer]

Originally Posted by RWebb

define "rebuild"

replace the pads when they are worn

replace rotors when uneven (check runout etc. with dial indicator) or just replace when you do the pads

replace brake fluid every 2 years

replace rubber brake hoses with new ones every 10-20 years

By rebuild - I'm referring to rebuilding calipers.

I'm looking at the pads, rotors and fluid as a fairly regularly replaced consumable. On the seals in the pistons, though, I'm not sure what the replacement cycle is.

At some point in the cars life, is rebuilding the calipers a maintenance item?

[djpateman]

I rebuild my calipers every 10 to 15 years it seems. When I actively tracked my car the fluid was changed twice a year. After a while the O-rings tend to take a "set". I guess I tend to treat the rubber in a caliper as a consumable like the pads themselves.

[James Brown]

Leaking, damaged, frozen, sticking, uneven pad wear, hard to push the car, rusted, torn dust seal, rust in the brake fluid (a lot), upgrading, retrograding, cad plating, pulling to one side, after a race season, whenever your really board. But no time limit.

[JBurer]

Thanks guys!