The master cylinder was shot on my '70 914, so i ordered a new 19mm replacement. While removing the old one a couple of the hard lines broke, so i went ahead and ordered new hard-lines for the front of the car. Once getting everything back together i went to bleed the brakes and nothing happened, I eventually pressurized the reservoir to 15psi and used a bleeder pump in the back also set to 15psi, and eventually got a little fluid and a lot of bubbles. I then moved on to the front and I am getting nothing up there, the reservoir itself has most of the fluid still in there. With the brake down I get no resistance in the back or the front.

My assumption is that this is an issue with the initial feed of fluid from the cylinder itself, probably on that tricky spot where the hose attaches to the master cylinder, but figured I would see if anyone on here has any insight on what else might be wrong.

There is no fluid leaking from anywhere, even when pressurized. The BMS was installed dry. Once again, and guidance would be greatly appreciated.

Thanks.

Rubber lines swelled shut ...

Pedal push rod is not seated in the MC bore (happens more than you think).

I install the MC and crack the fittings coming from it. I let it drip for a bit and then try to pump 'em up.

The master cylinder NEEDS to be bench bled for quick bleeding of the rest of the system. Otherwise you'll be there for days and go through 4-5 quarts of brake fluid. If you don't want to take it out again, you need to pump the pedal for 5m or so, let some air/fluid out of each caliper, then repeat tomorrow. Takes time to let the bubbles move around.

Thanks for all this info, didn't think of the soft lines swelling shut but it makes sense. its probably time to replace them anyways. Can anyone recommend a good source for SS soft lines?

Starting point seems to be a bench bleed, then I can verify that the inlines are correctly seeded.

Thanks again.

I would start with adding the pressure again and cracking the lines out from the MC until you get fluid. Since you replaced the lines also I would continue down the lines and crack each one until you see fluid. Then try to pump the pedal and bleed again normaly!

Concur with bench bleeding the MC prior to installation, but since it is installed, I would agree with Jeffs9146 approach.

As for brake lines, a common thought is that stainless lines fail sooner than rubber, and many on the forum recommend going with rubber. As for a source one of the best is PMB Performance - great service and quality products:

http://www.pmbperformance.com/catalog.html

Another good all around parts source would Pelican Parts:

http://www.pelicanparts.com/catalog/shopca...144_catalog.htm

Bleed it right at the master cylinder, and be careful NEVER to allow the piston to bottom out. Make sure there's a little free play in the pedal. SS braided Teflon lines are great for race cars where there are no road hazards and you replace 'em every season. Meanwhile, most folks get 20+ years out of the rubber ones.

The Cap'n

Foreign body or plug in the supply port ?
It's very difficult to seat the supply tubes with the master bolted in.
Any chance the supply tube grommet got tortured ?

Ok, I am sold on the standard soft lines. Thanks for the quick lesson in practicality.

Anything is possible with the fluid feed. I detached the reservoir from the trunk when I removed the BMC, and that gave me a lot of slack to attach it before securing the BMC, but all that said I could have totally messed up attaching it. The car is up on blocks, and its easy enough to get to everything to remove the master cylinder again, and bench bleed it. I started this project to get rid of soggy brakes, may as well do it right.

I do not have the master cylinder priming kit, but it seems like I can do it with the standard reservoir and a few tubes to cycle the fluid. Any tricks beyond mounting it level in a bench vice?

Thanks again everyone, I will update when I have time to wrench at it again.