brake warning light, red light at top of left dashboard gauge Options

[fiacra]

That was a nice write-up Brant. That is exactly how my MC failed. The car had limited use before I bought it, and the MC failed within the first few miles of driving it. The light came on and I pulled the pedal board and immediately found the leak. I didn't even bother checking the parking brake first. A malfunctioning parking brake switch is not inherently dangerous, a failing MC is, so why would your diagnostic flow chart start at the switch? It's on the flow chart for sure, just not the top of the chart. At that point I did still have functioning brakes and the only sign of failure was the light. I've since figured out that in my car (1975) the light blinks when the parking brake is on, and it stays on when the MC fails. Not sure about an early car.

If the MC has failed then the car is dead in the water until it is replaced and the rest of the system is checked. Replacing the MC is one of the most unpleasant jobs I've done on my car, and because the first MC I got was defective I had to do it twice. If you do not have a safe place to work, the right tools, and confidence in your mechanical abilities you should take it to a shop. It will be expensive at a shop, but probably less expensive than the consequences of brake failure. If your soft lines are more than 10 years old I would just replace them now as well. They probably will look fine on the outside, but will be swollen on the inside. Inspect your wheel calipers and consider sending them off to PMB for restoration. Check (and replace if needed) your rotors and front wheel bearings now. You have to bleed the system, and that is not an easy job as well, so now is the time to take care of any other problems that require you to open the system. I don't know why it is so hard on these cars to get all the air out of the system, but I needed three quarts of brake fluid and a pressure bleeder to get it done. That is just my experience, others have found it to be easier. I did also replace the lines and hoses from the reservoir. I didn't fully pull the tank to do that, but I did need to move it in order to feed those lines through. Don't forget a new grommet for the lines and a new washer for the banjo fitting at the MC. Get an extra rubber plug in case you tear one. It's cheap insurance against a common problem that will hold you up if it happens. As I said, my first MC (from a well known World vendor) was defective. The second time around I got an Ate MC. Twice the cost, but three times the peace of mind.

Here's a link to Ian's video about replacing an MC. I'm not dissing the source for his MC, but mine was defective and that led to a lot of extra work (and cost) for me. I'd go with the Ate MC if you can. My problem was likely an anomaly, but we are talking about brakes. No need to take chances.

https://www.youtube.com/watch?v=N6ZHK5f_9bE

[dlindzey]

thank you gentlemen, I would assume that everything is 50 years old so it looks like trailer to porsche shop as it is 100 miles away and see what happens and agree brake job while it is apart but i want to get at that MC and see if it is leaking and hit the reset button first if I can

[Literati914]

Does your "fasten Seat Belts" light work as it should? .. it is tied in to the E-brake switch if I'm not mistaken. At least on the '72 model (my harness has some attributes of the '71 apparently), these two wires come together at the back of the combo gauge and run thru a diode just before the bulb. (there is a second diode just before the alternator bulb too btw).

[dlindzey]

Does your "fasten Seat Belts" light work as it should? .. it is tied in to the E-brake switch if I'm not mistaken. At least on the '72 model (my harness has some attributes of the '71 apparently), these two wires come together at the back of the combo gauge and run thru a diode just before the bulb. (there is a second diode just before the alternator bulb too btw).

I don't think that I have a seat belt warning mechanism