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Old 02-21-2003, 08:34 PM   #1
Dads72
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Brake problem

Sometimes when it gets very cold, the brakes act as if the power brake assist (on a 72) is not working. Sorta like trying to use the brakes with the key off. You have to push real hard.
Planning on getting all the old fluid out of there and replacing it with new.
But, is there a possibility that moisture has gotten into the power assist and is freezing up? If so, how do I fix it? Replacement?
Again, if so, does the master cylinder have to be replaced also?
Thanks
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Old 02-24-2003, 10:40 AM   #2
smokekiki
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The first thing to do is what you said,change the fluid.Check the condition of the rubber vac line.
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Old 02-24-2003, 01:02 PM   #3
72CustomCamper
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Had the exact same problem on an AMC Matador once. The rubber grommet for the vacuum line on the booster was old and cracked. It only leaked when it was cold (rubber was more brittle).

$.79 and 90 seconds of work fixed it. (that price was 12 years ago)

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Old 02-24-2003, 04:41 PM   #4
1971LT1SWBPOSI373
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Check the white check valve that goes into the power brake booster where the grommet is. You should be able to get one or two applications of power brakes after your engine has been turned off. If not the check valve and/or the grommet may both be shot.
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