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

[dlindzey]

I think it is a brake warning light and from what I have read it subserves two functions. If still on after the engine starts either parking brake is on or you have brake failure. In my case parking brake is not on and brakes seem to work ok. It came on a few months ago and then went off and I thought might be a short so I have just not used the parking brake for months. Today it is on again and won't go off.

There is not much working space around the parking brake so I never did find the little button that is activated/deactivated for the parking brake.

Anyone know what I am talking about or have any suggestions for trouble shooting the matter? TIA dll-----I forgot 1971 model

[dlindzey]

thank you everybody for the advice and been there done that information. Let me update you and ask some further questions

I never had the blinking brake light failure indicator issue. My warning light just stays on post start up.

I was able to get the seat out and then was able to get the switch out. It only has one contact for wiring and has a brown wire with a white stripe. It seems functional so I reinstalled it and the brake warning light remains on. Many of the replacement parts have two contacts for the switch so not sure what to think of that. I ordered one from auto atlanta that seems to have just one contact so I will see if that corrects the problem but I am thinking it is something else.

Is there any explanation other than failing master cylinder? Fuses, shorts any well know alternative points of failures.

I have turned my tire and can see parts of the master cyclinder but can't get at it to reset a switch or see if it is leaking. Is the plate that has been referenced underneath the car so I need jackstands or a lift to further trouble shoot? Any further recommendations for those that have been in this situation?

[brant]

thank you everybody for the advice and been there done that information. Let me update you and ask some further questions

I never had the blinking brake light failure indicator issue. My warning light just stays on post start up.

I was able to get the seat out and then was able to get the switch out. It only has one contact for wiring and has a brown wire with a white stripe. It seems functional so I reinstalled it and the brake warning light remains on. Many of the replacement parts have two contacts for the switch so not sure what to think of that. I ordered one from auto atlanta that seems to have just one contact so I will see if that corrects the problem but I am thinking it is something else.

Is there any explanation other than failing master cylinder? Fuses, shorts any well know alternative points of failures.

I have turned my tire and can see parts of the master cyclinder but can't get at it to reset a switch or see if it is leaking. Is the plate that has been referenced underneath the car so I need jackstands or a lift to further trouble shoot? Any further recommendations for those that have been in this situation?

so there has to be a reason the light came on
I don't actually know if blinking, solid means anything different. doubt it... its a very simplistic system. I don't have an early car (your 71)

that light is turned on by the parking brake...and by a safety switch on the MC to warn you of brake failure..... its not something to ignore, and you could loose the majority of your braking on the next drive... thus the warning light. the parking brake switch is the easy one to access... rule that out first. just unplug it and see if the light goes out... it could be a bad switch... mostly they do not fail... the brake handle just misses the plunger and doesn't trip the switch... easy to rule out.. easy to check...
and then you move on the the hydraulic brake circuit next.


new cars have warning lights to tell you your fluid is low... a floating switch in the reservoir... similar to a toilet.

914 never had that.
the switch on the MC is to tell you the piston over extended triggering a failure switch to turn the light on. A sealed hydraulic system will not trigger that light.

meaning if this is what is triggering your light... it was down on fluid or leaking enough to allow the MC piston to over extend.

was your system out of fluid?
do you have a drip on the floor or inside of a wheel? (indicating a leaking caliper... make sure to check all 4 calipers for wetness)
did you recently bleed your brakes and have the closed system open for this service?


you really should bleed your brakes every other year or more
sitting parked is the worse thing for your brake system
the brake fluid absorbs water... then starts to rust inside the calipers, MC, full system

thus bleeding every other year to get the water out.


you could have a shorted wire.
I'm assuming the single pole sensor on early MC's is a grounding wire. the circuit grounds when the switch is triggered and turns the light on.

the real test would be that on both of the hand brake switch and MC switch you would test for a short by pulling the wires off of the switch and seeing if the light goes off when you break the circuit. dash light stays on when both are unplugged... means its getting a ground signal somewhere else from a broken wire short.


beyond a shorted wire.
the much more likely scenario is that you have not bled the brakes frequently enough to keep the water out of the system... the car then sat a few years.. pitted the MC piston or bore.... then fluid leaked past the rubber piston boot inside of the MC... thus the system was no longer a sealed system... the piston over extended and triggered the safety switch... turning your light on.


do you know when the brakes were last bled.
or the MC last replaced?

if over 10 years then you very likely have a bad MC unless the vehicle is getting the brakes bled regularly.

you will be able to tell with a few simple tests.

do you work on your own cars? tools?
no shame to use a mechanic
but with the purchase of some tools, and beer for your mechanic friend to come over and help you this is very doable and something you can learn.

you do need jack stands, and a jack.
you will need some hand wrenches, and allen socket wrenches

if the MC has actually failed the leaking fluid will be inside the rubber seal on the rear (as installed) of the MC where the brake pedal plunging rod enters the MC (under the brake pedal from the inside cockpit of the vehicle.)

if it has leaked... it will destroy your pedal bushings and any paint on the pedals and floorboard area below the MC

taking the pedal board off and potentially the pedal cluster is not a fun job as it is under the dash... but also not the most difficult job either.

if the brake fluid has gotten on any painted surface it will begin to rust soon.
very likely some of the rusted front floor pan cars you see that need major work, started the rust in the pedal area from a leaking MC that no one addressed in time.

the stock bushings in the pedal cluster are nylon. they swell and make the pedals sticky pretty soon after they get wet from brake fluid. most rebuilt pedal clusters will use brass bushings as a non factory upgrade that is more durable.

the pedal board is a bit tricky to remove
only 2 allen bolts... but takes a bit of wiggling to get out

since your car is early you likely wouldn't of originally had a center console.
that makes getting the pedal board out much easier.


but to diagnose your problem
you need to check for a shorting ground wire.

you need to put the car on front jack stands... remove the suspension pan... and test the wire on the MC switch... you can reset the safety switch with the reset button.

if the brake circuit is still sealed... not leaking any where then resetting the safety switch will solve your problem. but doesn't explain how it got tripped or turned on it the first place. most likely it was tripped/turned on by a MC leaking.

they don't leak to the underside where the suspension pan and switch are at.
they leak on the interior side where the brake pedal plunging rod enters the rubber boot at the brake pedal... (under the pedal board)

so thus the reason for tearing the interior apart and removing the MC boot at the pedal cluster to see if there is any wetness from fluid leak.

do you have a friend or neighbor you can get help from?
or schedule a work party on a weekend with other 914 guys in your area....
buy pizza and beer and they will help show you

most importantly... buy a haynes manual
it will teach you a lot.

if all of this is over whelming... take the car to a porsche shop that knows older porsches....


Replacing the MC if it is leaking is an whole 2nd job....
its annoying and not easy. involves often pulling the fuel tank and fighting the soft brake lines for a few hours that feed the replacement MC

most go to 19 mm when they do have to replace.
stock was 17mm but no longer available.
and as I said... depending on damage done to paint
potentially you are addressing the peeled paint in the pedal area damaged by leaking fluid... and rebuilding your pedal cluster at the same time again as a result of damage by leaking fluid....


see why you should bleed your brakes annually or every other year?

brant