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Old 04-08-2013, 05:33 PM   #1
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Default Poor Braking w/ new calipers and pads, firm pedal

It is a 92 with 94+ brackets and rotors,
-Porterfield R4S all around
-All brand new stock style calipers
-brand new master
-Wilwood proportioning valve (have tried various settings)
-Firm pedal no excess travel
-brake booster has vacuum upon running engine, turning off and then pulling check valve hose.

Stopping isn't great, little to no "bite" and was like this before changing all of the above, WTH? I can only imagine something is still bound up or there isnt enough vacuum getting to the booster after initial press of the brake??? The flex lines are stock, can they really expand enough to cause this kind of problem?
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Old 04-08-2013, 05:36 PM   #2
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replacing lines will make the pedal more firm and consistent, but won't provide any more "bite"

sport mc will probably give more bite

no idea how good those pads are but often pads are the culprit between bite and no bite as well
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Old 04-08-2013, 05:43 PM   #3
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Bedded pads?
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Old 04-08-2013, 05:48 PM   #4
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It should be better than it is w/o sport master and booster, it was before. Others have said those pads are similar to Carbotech's Bobcat?

I am thinking that the "bite" may be mitigated by poor vacuum to booster and was thinking the same with lines... idle sits at 20Hg or just above according to guage connected to same line but pumping brake will cause it to fluctuate.

I am going to try replacing the soft lines that go to the booster (from intake to hard line and the check valve bit), then might try another more normal pad. But like I said it did it before with regular pads but they were toast and so were the calipers they were in, hence my changing ALL OF IT.
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Old 04-08-2013, 05:50 PM   #5
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Quote:
Originally Posted by Oscar View Post
Bedded pads?
Err, went out and stopped hard from various speeds 60, 50, 30 etc. IDK. wasn't noticing much change... How much more would they need?
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Old 04-08-2013, 05:51 PM   #6
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^ Can't get a skid from crap tires even.
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Old 04-08-2013, 08:30 PM   #7
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Quote:
Originally Posted by Oscar View Post
Bedded pads?

BINGO!!! It just wanted a whole lot MOAR HEAT Much better!



Went out to the office/industrial park by my house and treated it like a track; slowly I could tell the pads were working both by feel and a lotta stink. Stink is good.
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