1982 SC brake fade

[Graeme]

Hi all,

I just joined the forum and have been searching but not yet found a solution to my problem so hoping someone can help me out ...

I recently bought a 1982 SC which is in great condition but I'm experiencing brake fade which seems to occur randomly - 2 times in 500miles, full fade, pedal to the floor.

My observations :

• 1st time it happened, I had been descending a long downhill ( at reasonable speeds ) so I assumed it was due to sustained breaking overheating the system

• 2nd time, in slow congested traffic

• Both times the front left wheel is extremely hot so I suspect the brake is binding, overheating and there is either water or air in the system causing the fade

• I leave the car to cool down, pump the pedal and all is "ok again" so I limped carefully home

• Car is pulling to the left on braking

• Brake fluid was replaced before I bought the car and looks fresh, no leaks

• master cylinder holds pressure with engine running

• brake booster passes the engine start test

Took the front wheels off and the F/L disk spins freely the F/R turns but is tight

My gut feeling is that the F/R piston is not moving, anyone have more educated / experienced thoughts before I start taking things apart ?

OR ... anyone have a mechanic they can reccomend in Santa Cruz, CA / the Bay Area ?

cheers
Graeme

[Gianni at Pelican Parts]

Hi Graeme,

Welcome to the Pelican Parts Forums!

We have some great "How To" Tech Articles specifically on the braking system and rebuilding your calipers if necessary, we also stock rebuild kits in our Harbor City warehouse in case you want to call one of our Porsche Parts Specialists!

[Charles Freeborn]

Dragging caliper. Have them all rebuilt by PMB, fresh lines, rotors, etc and you'll be good to go.

[jpnovak]

Time for caliper rebuild and flex line replacement on all 4 corners. The caliper pistons will corrode on the edges and stick in the caliper bore. The flex lines will swell internally and prevent fluid from returning to the MC. When this happens the caliper drags and the friction will boil the fluid. gaseous brake fluid does not stop a car.

Caliper seal kits are cheap and this is a pretty easy DIY project if you are reasonably competent with some wrenches.

[Graeme]

thanks all !!!
Makes sense, I'll read up on all of the above and decide whether to dive in or find a mechanic

[RDM]

Originally Posted by jpnovak

gaseous brake fluid does not stop a car.

Does the fluid boil or the water dissolved in the fluid? I always thought it was the latter.