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HybridZ

Changed brake vacuum line, pedal pulses


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1978 280Z. Stock front discs & rear drums. NOT warped rotors, you can feel the pulsing while completely stopped at idle. Varies with engine speed.

 

So, I've been going through little by little replacing "suspect" parts. My brakes seemed very soft through about half-travel then gave good resistance from there. Car stopped fine, could lock brakes even.

 

Due to the fact there were four pieces of line, a pressure (why, no idea, didn't read anything) gauge making up my brake vacuum line, I thought it was worthy of replacing. Vacuum line ran from the rear-most intake tract to the MC, new line follows same path.

 

Now, I can feel distinct intake pulses from the intact tract in the pedal. Feel is more linear than before throughout pedal travel. Am I supposed to feel the intake pulses? Should the vacuum line pull from more than just the one intake tract to smooth out feel?

 

Thanks for the input folks!

 

JM

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Was there was a check valve in the old system?

 

Didn't appear to be, UNLESS the pressure gauge (with on/off adjustment knob like on a air regulator) was providing a check valve. Other than that, there was nothing special in any of the lines, just male-male connectors.

 

It would be easy enough to cut the new line and put the pressure gauge back in.

 

JM

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Install the check valve that is supposed to be there. Make sure you face it to allow flow towards the engine.

 

Sure the male/male connector isn't your check valve? It's a pretty simple looking part...

 

Nope, didn't really look any of it over. When I get home this afternoon I'll look over the old stuff and find which was a check valve. I'll reinstall that piece and it sounds like that'll fix the problem.

 

Thanks for the help folks, I'll update with the results later this evening.

 

JM

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