Brake issue - Second Generation Pontiac Firebird (1970 - 1981) - Firebird Nation

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Brake issue


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9 replies to this topic

#1 edteach

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Posted 3 days ago

I noticed the last two times I took the FB out the brake peddle goes down a long ways and is hard. I have to put a lot of pressure on it to stop fast. Going slow it seems to work ok but the peddle goes down more than before. I checked the BF reservoir and its full. No leaks. Not sure what it the issue. I can run it to a brake shop but if I can figure out the issue myself all the better. Thanks for any help



#2 ZumpTA

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Posted 3 days ago

Hard brake pedal is most often a vacuum (lack of) issue.


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#3 edteach

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Posted 3 days ago

Thanks. I will check the vacuum lines coming off the PB unit.



#4 JOE68

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Posted 3 days ago

if your rear brakes aren't adjusted properly it will cause excess travel and poor braking



#5 edteach

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Posted 2 days ago

So I did a quick look at the vacuum lines from the PB and I don't see anything obvious. I was going to start it and run some eather to see if there is a leak. but what I did find is one of the long vacuum lines from the cruise control goes along the fire wall and then hangs just under the AC compressor hooked to nothing. Where does this line go? I could not see any place it was obvious to hook in. Thanks for any help

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#6 b_hill_86

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Posted 2 days ago

That line goes to the servo (diaphragm) thats mounted on the firewall (assuming you have a 400) which you appear to be missing.

#7 edteach

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Posted 2 days ago

Mine is a 301. So why would this line be hanging there? Is this an open vacuum line? If so I should remove the line and put in a cap?



#8 b_hill_86

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Posted 2 days ago

Its still for the servo. I forget where a 301 servo is mounted. On the intake if I remember right. There is no vacuum on that line unless the cruise control is engaged so it shouldnt cause any harm.

Since you dont appear to have a servo your cruise obviously wont work so if youd like to remove the cruise from the vacuum system there is only one line running from the B port on the transducer over to your carburetor most likely. You could remove that and cap the port on the carb and wouldnt have to worry about any leaks involving the cruise system

Edited by b_hill_86, 2 days ago.


#9 myk74

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Posted 2 days ago

Check that check valve in the booster too. I have had those restrict vacuum before.



#10 edteach

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Posted A day ago

The vacuum check line is fine, I removed the hose and capped the entry point to the cruise. I found one of the cluster going to the breather that did not have a line on it. Just a nipple coming out of the cluster so I capped it. Nothing else I see. Now have to take it for a drive to test it.






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