Re: HOLY S#$%&T BRAKE FAILURE!
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Forum Ambassador
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Believe you have power brakes so did the brake pedal suddenly become rock hard and you really have to stand on it before something happens or did the pedal just go straight to the floor and no brakes?
Going rock hard could indicate a complete loss of vacuum assist but you still should have a bit of pedal and brakes. Going to the floor is the typical symptom when the compensator valve suddenly fails to close. Having it work again right after a failure usually indicates some kind of debris floating in fluid down inside the ram portion of cylinder which moved and lodged under the valve and prevented complete closure. If the fluid did get all the way to the engine, it would indicate the vacuum canister portion had quite a bit of fluid inside it. Pushing the pedal down could have met the fluid and the resistance could have stopped pedal movement and brake application. It could have also forced fluid up high enough in the canister to reach an opening on the piston where the vacuum could suck it past the piston and into the vacuum valving and on to engine. That much fluid inside would mean a badly failed seal and the fluid reservoir should have been in need of constant refilling -- or with the drive home, almost empty by now.
Posted on: 2014/12/23 14:27
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Howard
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Re: HOLY S#$%&T BRAKE FAILURE!
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Home away from home
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I do have power brakes-the notorious BTV unit. The pedal did go to the floor.
Posted on: 2014/12/23 14:50
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Re: HOLY S#$%&T BRAKE FAILURE!
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Home away from home
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You mention you were on your way to where you store the Packard. How often do you drive the car? More to the point, how long does the car sit between "drives"?
Posted on: 2014/12/23 17:27
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1951 200 Deluxe Touring Sedan
1951 200 Deluxe Touring Sedan (parts ?) 1951 Patrician Touring Sedan 1955 Patrician Touring Sedan |
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Re: HOLY S#$%&T BRAKE FAILURE!
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Home away from home
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During the winter it usually sits for quite a while.
Posted on: 2014/12/23 18:14
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Re: HOLY S#$%&T BRAKE FAILURE!
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Home away from home
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Cheque the fluid reservoir of the master cylinder to see if it is significantly low on fluid.
Posted on: 2014/12/23 18:45
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VAPOR LOCK demystified: See paragraph SEVEN of PMCC documentaion as listed in post #11 of the following thread:f
https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?topic_id=7245 |
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Re: HOLY S#$%&T BRAKE FAILURE!
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Home away from home
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I can almost guarantee you are going to find a chunk of something floating around in the reservoir. It held the valve open.
Posted on: 2014/12/23 21:40
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Re: HOLY S#$%&T BRAKE FAILURE!
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Home away from home
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Well Ross I know and respect you as someone who just knows about EVERYTHING that can go wrong in these cars, One thing that has always mystified me-why did Packard mount that thing in such an inaccessible place (under the floor right below the steering column)?
Posted on: 2014/12/24 0:01
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Re: HOLY S#$%&T BRAKE FAILURE!
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Home away from home
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Short version, NOT Packard specific but general US auto production:
The BTV was one of the first WIDELY used PRODUCTION powerbrake units. It had to fit to a PREwar PLATFORM that was not ever developed with power in mind. A prewar platform that was carried over well into themid 50's. Not until about 58 or 59 did the general platform of the US automobile become redisigned for low, wide stance necessary to accomodate the Interstate hiway system that was just barely in the planning stage mid 1950's. By 58 or 59 WIDE V8 engines, 70 to 120 mph SUSTAINED speeds etc etc etc. that did NOT exist nore was necessarry for the prewar carr and its carry over into the early 50's. So the BTV was a "get me thru the nite" kind of make shift, shoehorn SOMETHING into an OLD design until we can do better. The BTV is a short service life, high maintenance (or in plain english a piece of shit) very early attempt at power brakes. THe Compensator valve that Ross speaks of above is the sore spot of the BTV. Unless one has disassembled a WIDE variety of master cylinders from a WIDE VARIETY of mfg'ers over a WIDE raange of years then one can not understand the shortcomming of the BTV. THe BTV master cylinder is a PECULIAR desiggn of unorthodoxyy in the world of automobile master cylinders taaken from the midd 1920's TO DATE!
Posted on: 2014/12/24 0:38
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VAPOR LOCK demystified: See paragraph SEVEN of PMCC documentaion as listed in post #11 of the following thread:f
https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?topic_id=7245 |
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Re: HOLY S#$%&T BRAKE FAILURE!
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Home away from home
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Scroll to the bottom and read the second from last post by Jalapeno about the BTV:
http://www.trifive.com/forums/archive/index.php/t-22857.html
Posted on: 2014/12/24 0:51
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VAPOR LOCK demystified: See paragraph SEVEN of PMCC documentaion as listed in post #11 of the following thread:f
https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?topic_id=7245 |
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