Braking issues

[Glorydays70]

I have a 70 Camaro with Wilwood brakes. 6 piston on front and 4 on rear. Small chrome booster/master cylinder was used due to clearance issues. Running a 502. I have driven car about 1,000 miles since completing it. Had a sudden stop situation this weekend and figured out brakes will not stop car. Car slows down and stops under normal conditions, if I jam o. The brakes it slows down gradually instead of locking. Master was bled when installed and system was bled. Scary stuff! Any ideas on what to look at first before I rip it apart and buy hydra stop? See lots of guys running manual brakes and talking pedal ratios, honest I'm lost on that.

[andrewb70]

I have a 70 Camaro with Wilwood brakes. 6 piston on front and 4 on rear. Small chrome booster/master cylinder was used due to clearance issues. Running a 502. I have driven car about 1,000 miles since completing it. Had a sudden stop situation this weekend and figured out brakes will not stop car. Car slows down and stops under normal conditions, if I jam o. The brakes it slows down gradually instead of locking. Master was bled when installed and system was bled. Scary stuff! Any ideas on what to look at first before I rip it apart and buy hydra stop? See lots of guys running manual brakes and talking pedal ratios, honest I'm lost on that.

The first step would be to figure out if your engine is making enough vacuum to make the booster functional. The second is to look at the MC bore size.

Andrew

[Glorydays70]

The first step would be to figure out if your engine is making enough vacuum to make the booster functional. The second is to look at the MC bore size.

Andrew

I backtracked part numbers on invoices, checked part number to manufacture. Master cylinder is 1 1/8" bore....it was supposed to be 1". Guess that's my issue.

[BonzoHansen]

My pads do that cold...

[ULTM8Z]

1/8" bigger on the MC bore will make a big difference in pedal effort (much more effort required on the bigger bore). Though when you go down to a 1", I think you'll notice significantly more pedal travel though.

[GoodysGotaCuda]

I backtracked part numbers on invoices, checked part number to manufacture. Master cylinder is 1 1/8" bore....it was supposed to be 1". Guess that's my issue.

I wouldn't go all that far and say "that's the culprit", 1-1/8" will probably work just fine when it's properly bled, good vacuum and bed-in pads.

Do you have vacuum assist for one or two strokes after you shut the engine off from an idle?

[c4racer2]

What's the vacuum at idle? I think it takes 12-14 minimum, if you are below that you may to do something different for the booster or go to manual.

My motor makes under 10 - rather choppy idle. But I'm running a manual set-up.