Ok, OK, I'm sorry that I (the big dummy) split the calipers in half on my 80 SC in order to "rebuild" them. Now I know. Not the swiftest thing I've ever done. I bought used ones as the cost of new ones was just too much, financially and emotionally. My old ones were in pretty sad shape anyway. Yeah well..........I installed the new/used calipers with no problems but CANNOT get them bled! Am I being punished? Exactly how long should this relatively simple task take? All lines are tight. No brake fluid leaking anywhere that I can detect. New pads. I've tried using the vacuum method w/o success and even had wifey "pump'em up" ad nauseum. She is no longer speaking to me. Do I need to bleed the rear brakes also to get the fronts working properly? The pedal pumps up very, very slowly and not to anywhere near the necessary pressure and then sinks slowwwwly to the floor. Arggggggggh. Not good. Any help will be appreciated.

 

Richard,

You do have the bleed the rears. Start with the caliper that is the furthest from the brake fluid reservoir, pass rear, then the driver's rear, then pass front and lastly the drivers front. When you open the brake system up like that you may have to bleed the system more then once to remove all the air from and get a firm pedal. Also keep an eye on the reservoir and don’t let the fluid level get to low or you will be introducing air into the system through the reservoir. Be sure to check for leaks around the MC also. You might what to look in to purchasing a pressurized brake bleeder to make the job easier, they work great and you don’t have to bother you wife to pump the pedal.

 

Hi,

If Driver8's explanation doesn't help you may need to bleed the master cylinder too.

Michael

 

One other thought, when you installed the new/used calipers, are the bleeders at the top or bottom? They should be at the top of the caliper.

 

above suggestions +1.

Also - try tapping the calipers with a mallet to dislodge any bubbles. Try bleeding with worn pads first, then install new pads. Make sure the bleed screws are on top. I have had very good luck with speedbleeders.

Are you sure you have a complete seal both around the calipers and with the piston boots?

 

Probably not your problem but it is possible the pistons have been pushed too far back into the calipers and the seal is not bedding in the correct place. Solution is to pump until some pressure is obtained and then block pedal against seat frame - leave for several days. This may have to be carried out several times until the pistons fit into their correct position.

Brakes are so simple when it all goes right and a pig when they don't. All the advice above should help. Good luck and keep trying!

PJC

 

Not much help to Richard but it might help others avoid the same problem. Before you open the system block the pedal like PJC says, this keeps the fluid from flowing and can save some major headaches.

 

Not trying to sell you anything here ,but, I recently totally rebuilt my SC brakes and SS lines and bled them in 10 minutes with a motive power bleeder. 0 problems. Try Vertex.com
Also go to Pelican and buy the 101 projects for your 911 book. It has a detailed write up on this.

HTH
Tim

 

Thanks guys/gals for providing the solutions and for sparing me the deserved critique of my "skills". I bought a power bleeder and all is well. Funny thing though is that I have the 101 Projects book already. I just thought I "knew" how to do this. I may be old but I'm immature. Wife sez to take it to the shop next time. A lot she knows.

 

Richard,

Glad you solved the problem, we all have to learn from experience and you don't get that taking it to the shop. For me part of the enjoyment of my Porsche is to carry out some of the tasks myself which gives me an insite into the great engineering that goes into the cars.

Keep on giving it a go - lots of people on the forum will offer support.

PJC

 

Try speed bleeders, make things easy. http://www.raceshopper.com/speed_bleeders.shtml