Re: BRAKES: Easamatic Power Brakes aka Bendix Treadle-Vac--Change or Not??
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Home away from home
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The smaller the piston then the less effort required by the foot. BUT the foot must travel a longer distance to displace a fixxed amount of fluid at a fixed pressure. So that is why the 1:1 RATIO works.
Put a larger piston in the bore and it becomes more difficult to push the pedal so the pedal ratio must afford more leverage to displace the fixxed amount of fluid at the SAME pressure.
Posted on: 2009/5/19 9:05
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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: BRAKES: Easamatic Power Brakes aka Bendix Treadle-Vac--Change or Not??
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Home away from home
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The "1 inch" specification in the manual is completely erroneous. If not i wish someone would explain to me otherwise. The BORE of the BTV cylinder is about 1-3/16 inch. THe piston is 0.655. I can not find ANYTHING on the BTV that is 1 inch +or- 1/16 inch.
Posted on: 2009/5/19 9:08
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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: BRAKES: Easamatic Power Brakes aka Bendix Treadle-Vac--Change or Not??
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Home away from home
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"Has anyone tried adapting a conventional PB cylinder on the BTV vacuum?"
The problem is finding such a master cylinder. It would have to be about .655 inch diameter +or- say an 1/8 inch maximum. ALSO such a cylinder would have to have a piston with enuf travel. Also it has to fit into a very tite place. The original factory set up places the end of the MC about 1/4 inch from the frame which is JUST ENUF clearance to allow for body sag and belgium block compliance.
Posted on: 2009/5/19 9:18
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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: BRAKES: Easamatic Power Brakes aka Bendix Treadle-Vac--Change or Not??
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Home away from home
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84'ish Honda Civic power brake set up comes real close. It has a 13/16 piston which is a just a bit too big for the 1:1 ratio. but the length of piston travel is just barely adequate. The unit fits into the space just fine. But the power unit and piston travel is almost too short. The pedal gets real hard.
Posted on: 2009/5/19 9:24
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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: BRAKES: Easamatic Power Brakes aka Bendix Treadle-Vac--Change or Not??
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Not too shy to talk
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My mechanic tells me I need a new brake master cylinder for my 1955 Patrician. He says that the Treadlevac unit appears fine (I had it rebuilt 15 years ago and it has only about 500 miles on it). My mechanic says that special tools and expertise are required to disconnect the old master cylinder from the Treadlevac unit and to attach the replacement, which I am thinking of ordering from Max Merritt in Indiana. I live in No. California but could ship the parts to anywhere in the country if someone could tell me a shop that can do this work.
Posted on: 2009/7/24 12:45
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Re: BRAKES: Easamatic Power Brakes aka Bendix Treadle-Vac--Change or Not??
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Forum Ambassador
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Actually, the TreadleVac unit is the hydraulic and vacuum cylinders combined. What I understand, then, from your post is that your mechanic feels that the (vacuum) power assist section is working fine, but the (hydraulic) master cylinder requires repair or replacement.
The original special tools are really not essential, but when needed, they can be fabricated rather easily if one reviews the procedure in the Packard Service Manual (archived here for your viewing pleasure). I've overhauled those master cylinders in my home garage with little trouble. The outlet fitting can be a bear to get loose; as such, it is best done first, while still attached to the vacuum cylinder - as shown in the factory shop manual. Often, the hydraulic piston has become pitted and will quickly ruin new hydraulic seals, but a new piston could be fabricated by a decent machinist out of steel or even stainlesss steeal (the latter alleviating the need for hard chrom plating). However, the condition of the compensator port valve spring is critical - yet not included in any kit. Corrosion from even small amounts of moisture absorbed into the hydrualic system over the course of many years will take its toll on this part, too, and failure of that spring will result in a complete loss of hydraulic action. In the absence of off-the-shelf replacements for such parts, one need look to a reputable and competent rebuilder who specializes in servicing the unique technology of the Bendix TreadleVac and has reproduced the essential parts. They will want the entire unit and go through it completely. Most people seem to favor Ed Strain, though I've not personally done business with him. A quick search on Google showed the following address and phone: Ed Strain 6555 44th St, Unit #2006 Pinellas Park, FL 33781 800-266-1623
Posted on: 2009/7/24 12:48
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Re: BRAKES: Easamatic Power Brakes aka Bendix Treadle-Vac--Change or Not??
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Home away from home
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Are u using DOT5 (silicone) or Dot 3 brake fluid?????
I would not expect rust in the system unless the car has been subject to extreme moisture conditions. Hi moisture is NOT exactly N. Calli climate conditions or is it??? 500 miles in 15 years????? Did the car set outside any during the 15 years??????? What has been the storeage conditions for the car?????? Or was the 500 miles of driving thru creeks and rivers or Tsunami floods or anything like that?????
Posted on: 2009/7/24 15:57
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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: BRAKES: Easamatic Power Brakes aka Bendix Treadle-Vac--Change or Not??
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Home away from home
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When u get the master cylinder off then take it apart. IT's REAL EZ to disassemble. Show us pics.
U can call me and we'll walk thru the disassembly of the cylinder. Phone number on request by Private message. U can still send it off to the rebuilder in a box assembled or disassembled. Basically u're sending them a core anyway.
Posted on: 2009/7/24 16:10
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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: BRAKES: Easamatic Power Brakes aka Bendix Treadle-Vac--Change or Not??
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Home away from home
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Look at the brake fluid. Is it dirty looking????? tell us what u did about the rest of the brake system 15 years and 500 miles ago.
Posted on: 2009/7/24 16:13
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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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