Symptoms of a failing or failed Master Cylinder

[Dbelleperc]

The 914 that I will be picking up at the end of this month has a brake problem. After about 10 minutes of driving the pedel goes stright to the floor without any pressure and you have to pump the pedel about 5-7 times before pressure comes back. Does anyone know what the problem could be? Air in the system, need to rebuilt calipers, or something else? Thanks.

[M. Hendrix]

After driving... hmm.. I thing you have one condition, compounded with another.

I think your soft brake lines are shedding their liners, and I think you may have some air in there, but it won't matter if the liners are separating.

When the MC is bad, the pedal refuses to return properly, and the action all comes on (or not) in a very short part of the throw.

I've been wrong before.


M

[Dbelleperc]

I forgot to add in the earlier post. Before the pressure is in the peddle I have to pump the peddle to the floor and bring the peddel up by putting my toes behind the peddle and pulling it towards myself. Then I will have pressure in the peddle and brakes. But once I release the brakes I have to repeat the process over again.

[M. Hendrix]

I think your MC is bad.



M

[John Rogers]

If it were me, I sure would not drive it home!!

[Dave at Pelican Parts]

Sounds like at least the MC is bad. Very possibly more. Check for rust around the pedal cluster--often a bad MC will leak brake fluid into the car, which will then eat the paint off the floorpan around the cluster. Rust, rust, rust....

You could easily have other problems with the brake system as well.

--DD

[Dbelleperc]

There is no rust on the car. But the brake fluid stays constant. Checked the reservoir every week.

And John I am shipping the car myself. I was just thinking what I may have to do when I bring the car back to San Diego. Anyway I plan to replace the rotors, pads, lines, and maybe rebuilt the calipers.

[Rouser]

Chances are, the (original, plastic) pedal cluster assembly bushings are all swollen/deteriorated from brake fluid getting past a wornout MC. Be ready to see fluid all over the cluster assembly upon inspection.

Also, save yourself the headache of going roundy-round troubleshooting or "bleeding out" a soft/spongy pedal by replacing the flex-lines to each caliper.

I've seen this issue arise over-and-over. Remember, the brakes just aren't the place to trim your 914 budget to save up for that used Saratoga Top on eBay, or those phat 18" rims & tires. So far, you look like you're heading down the right road, figuratively.

[Dbelleperc]

I'll take that as a complement, I am getting this 914 from my uncles son in Dallas and he got the car from my uncle. I plan on doing a complete restoration and have the car running, and ready to go.

The car will be a garage queen only coming out to get cleaned or to have some fun on the weekend.