Brakes don't Bite Options

[bkrantz]

As part of my rebuild I completely replaced the brake system:
calipers and rear pressure valve rebuilt by PMB
new ATE 19mm master cylinder
new hard and flex lines
new disks and Porterfield R4-S pads

I went through many (many!) episodes of bleeding, with different methods. The pedal feels very firm from the first push, and does not pump up. Rear clearance is set at .004". I went through the PMB bedding process, and have driven around a bit.

But the braking force seems weak. When I get on the brake pedal, I do not feel any "bite". Another 914 friend drove the car and also agrees.

Any suggestions?

[Literati914]

Man this is frustrating, hate that you’ve not got it figured out yet.. good luck tho, I’m sure it’ll come good soon.

But it’s got me wondering.. what the whole procedure at the factory must have been like? I mean I doubt it was ever anything more than simple and routine. And of course that was with new caliper seals too. I assume brakes could be locked up on new 914s, right? No extra floor braces needed (though I do like that idea).. no dozen bleed sessions..etc.


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[Superhawk996]

Man this is frustrating, hate that you’ve not got it figured out yet.. good luck tho, I’m sure it’ll come good soon.

But it’s got me wondering.. what the whole procedure at the factory must have been like? I mean I doubt it was ever anything more than simple and routine. And of course that was with new caliper seals too. I assume brakes could be locked up on new 914s, right? No extra floor braces needed (though I do like that idea).. no dozen bleed sessions..etc.


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I don’t know what was done in Factory for 914 but suspect it was similar to modern process. It’s referred to as Evac & Fill.

System is 1st put under vacuum to remove all air and moisture from the system. Then vacuum is held for a period of time and the system is monitored for leakage.

When leak check is complete, brake fluid is then filled under mild pressure.

That is the best bleed the vehicle will ever get.