vagluv

When I started the car this AM the "Brake" and traction light flashed slowly. I let it run for about a minute to see if they would go off, but they didnt. Upon turning it off and back on they went away and havent come back. It seems to be running correctly, and the brake fluid is at the proper level.

Any ideas?

Thanks!

Indycam

Try switching to on , waiting till the pump stops , I'm guessing you have a C4 , then starting the motor .
Does the light problem change ?

vagluv

thats what ive been doing for start-up.

what is running? fuel pump? theres also a fan noise from the rear. these take a good 20+ seconds to stop. a little difficult to wait for an impatient guy like me, but ive been in that start up habit for a while.

Indycam

Do you have a C4 ?

Ok , I went and looked at your other posts , you have a C4 .
The C4 has a pump located in the front trunk , it sit just ahead of the battery and just behind the bumper .
Before you start up the car in the morning pop open the front hood , then reach in via the open window and switch the key to on .
Walk to the front of the car and look for the pump that's running .
That pump is what gives you power brakes , it also works with the all wheel drive system .
That pump should run for a bit and then switch off .
Once it has switched off get into the car and step hard on the brakes , after 5 or so steps hard on the brakes the pump should run again .

If that pump fails the brakes become hard as a rock .

vagluv

thanks, ill check it out.

vagluv

Haven't had this issue again, but the pump that is associated with the hydraulic system is fairly loud (not horribly, but it groans louder than I would expect it to), which is leading me to believe it could go soon. What is that part called?

Zingari

I think the pump is quite noisy - mine is and can be heard inside the car when the ignition is on.

vagluv

Looks like this would be the part. $520 cheaper than PP through ECS...

http://www.ecstuning.com/Porsche-199...ABS/ES1477386/

Indycam

They do make noise , I've never heard of one being replaced because it makes noise .
I suggest you find another 964 C4 and listen to its pump .

Do you see that big green switch on the side of the motor ?
That switch is important .

Cartod

What you have described is exactly what my low mileage (55k) C4 does. Turn the key on (without starting) and let the pump run until it stops (about a minute). Problem solved. If I get in the car and take off from a cold start the lights will come on and the alarm will sound until system is fully pressurized. You can occasionally hear the hydraulic pump working during driving. Make sure your fluid level is correct.

canuck964

1990 C4 also with low miles (30k) and mine does exactly the same thing. Pump is quite loud and can be heard in the cab. Been the same for all of the 20 years I have owned it.

Check out this discussion - https://rennlist.com/forums/964-foru...ling-bomb.html

Cartod

I read through that again and remembered replacing my accelerometer years ago. Actually I just took it out and cleaned it. It’s worth reading about it. I’ll find a link.

Accelerometer thread :

https://rennlist.com/forums/964-forum/963577-fixing-abs-pdas-warning-lights.html