856666

I installed a Ecklers power brake (dual MC) kit on my 65' L79.

I noticed the brake pedal gets hard to push after the first push, when the engine is at idle (stop and go traffic) but when on a mountain road and braking into a corner on decel (vac high) the pedal is responsive - no issues. So my assumption is there is not enough vacuum at idle for the booster.

My engine vacuum at idle is 15-18 and the trouble shooting guide I have say's vacuum below 18 requires a reserve canister or an assist vacuum pump.

Question #1 - what vacuum do other L79 with PB owners have and do you also have a hard pedal at idle after the first pump?

Question #2 - does anyone use a reserve canister or assist pump?

Thank you,

Phil

- thanks John Z -

Velox

Well in my opinion, your vacuum reading seems adequate and you should not lose your pedal after one pump when you have a minimum 15 inches of idle vacuum. My L72 has about 14 mm Hg idle vacuum and the pedal works fine, does not lose PB effect like yours does. Is your 'kit' the stock size vacuum booster? Is your vacuum fitting and hose correct, intact and not leaking? Is your power brake booster vacuum check valve in good shape, working correctly, did you check it, try changing it out for a different or new one? To me it sounds like your booster is not working correctly. You should NOT need a reserve cannister or assist vacuum pump in a 65 with stock style system power brakes, good vacuum source and properly working components. Just my opinion, YMMV

bbxlr8

Mine is a 67 L79 w/ PB added (not factory). I have no issues and will check the vacuum, but second the idea that something is not right - you shouldn't need a reserve or assist.

65air_coupe

I never had anything similar with my mostly stock '65 L79 with 66 master cylinder/booster conversion. Unfortunately I never ran a vacuum gauge on it either so can't provide any numbers for you. Running same brake system with my 406 with a hydraulic roller cam without problems either.

66jack

I would check this first...they are a quick cheap fix....

bosshog8

I also have never had any issues with idle vacuum and the power brakes on my L79. I agree with checking the check valve or look for a leak somewhere. Even new parts can be faulty.