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I had a bad experience with my BTV when i had it at a garage getting it back running after it had sat for 10 years, it appeared to completely suck all the fluid out of the mastr cylinder. So I was worried about it, knowing it had sat for 10+ years, it's problems with cruddy fluid (and having a bad experience with this particular master cylinder), and also knowing the cost to rebuild one ($400), I made an experiment where I retrofitted a 1971-1975 Ford Courier master cylinder (dual master, 3/4" bore),

14976-05229974

partsgeek.com/gbproducts/MC/14976-071157 ... l?utm_content=MC&utm_term=1972-1975+Ford+Courier+Brake+Master+Cylinder+A1+Cardone+13-1777+72-75+Ford+Brake+Master+Cylinder+1973+1974&fp=pp&gbm=a&utm_source=google&utm_medium=ff&utm_campaign=PartsGeek+Google+Base&gclid=Cj0KEQjwi7vIBRDpo9W8y7Ct6ZcBEiQA1CwV2H3IoXcgyord1BxPKQrkEdOAi3Y4G9Lg4wJXIOnXFqcaAmWj8P8HAQ&ad=47362750812


This was the smallest-bore master cylinder I could find. The mathematics say that to match the 0.652" single-cylinder BTV, I should get something like a 1/2" bore dual-master, but I could not find anything like that.

I coupled this to a 1981 Ford Courier power booster (7" nominal diameter). Turns out it plugs right in:

Part # 53-5211

oreillyauto.com/site/c/detail/OBH3/53521 ... 1&pt=01305&ppt=C0066#itemDetailTab_


I was able to make this fit, and with the help of a few adapters from metric to English, and some tees, I was able to get everything attached. To get the thing attached to the brake pedal I bought a 10mm fine-thread rod end from FK Rod Ends. Not many people make 10mm find-thread rod ends, and in the U.S. I think they are only available from FK. to make it fit I had to grind it down to make it narrow enough to fit into the brake pedal.

fkrodends.com/

fkrodends.com/CMMCFM7.html

Everything fit together. I fabricated a bracket and was able to remotely mount the reservoir.

It actually looked really good and was easier to get to and service in comparison to the BTV. I attach a bunch of pictures.

But - even with the larger booster, it just didn't give you enough brake power. I could deal with it, but I had other people drive it and they thought it was just too hard to push on the pedal. I ended up rebuilding the BTV using the kit from Kanters, and I am much happier with the braking now.

But it is still darn-near impossible to check the brake fluid level, the best I can do, really, is to stick my finger in it from either way on top or underneath, and see if the level is at where I think it should be on my finger.

Has anyone, at the very least, retrofitted something to put a remove reservoir. I know the current cap is vented, but maybe if I replaced it with a pipe fitting? Does that fit?

I really like to be able to check everything when going on a trip, or in the middle of it. It gives one peace of mind.

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The rest of the photos are in that Zip file attached above.

Here is a sample:

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The problem with modern masters is they all push fluid ahead of the piston and on a power brake system require a pedal ratio of at least 3 and preferably 4 to 1. Most manual systems use around a 6:1 ratio. Pistons are generally short stroke, large bore and with the typical 1" master and approx 1" wheel cylinders, there is not much hydraulic advantage. The smaller master helps but still mostly relies on mechanical advantage.

The Treadlevac has no piston as such and fluid is moved out by the action of a solid cylinder of metal moving into an enclosed space and displacing the fluid which totally surrounds the solid metal. The stroke is longer and because the fluid is displaced rather than pushed, there is more hydraulic advantage and the pedal ratio can be less. In Packards case the power brake is at the end of the arm so the ratio is 1:1.

Several have tried to use the existing suspended pedal with the Packard location and it just cannot be done and have a safe brake system. Believe Craig was the first to keep the stock location with a modern power setup but had to modify the pedal to get a ratio within the recommended range. Others have moved the booster to the firewall vent area so it can be connected higher up on the suspended pedal arm to get the needed ratio.

Problem with modifying the pedal to get the ratio and keeping the master in the original spot is the pedal changes location by moving lower, sticks out farther, and mod is very obvious so no way to maintain the factory inside look.

Yes, there was an accessory remote reservoir which mounted higher on the cowl. They were available for decades but I don't know what today's availability is.

I agree it's not the easiest but I find checking the fluid in my BTV (56 Carib) to be a relatively simple job if you first remove the flexible air duct hose.

There have been some who would like to see a repro of the factory kit and one member was thinking about doing it at one time. Haven't heard if anything ever happened though.

Some have used modern remote reservoirs by modifying the existing cap but the kit that is most complete and comes with a new cap is sold by a fellow in Texas. There are some photos of it on Big Kevs blog if you want to search.

The contact info for the person selling that kit is in the fourth post on this thread The info is almost 3 years old but as far as I know it is still good and the kits are still available.

I lean over the fender, remove the cap and look with a flashlight. These cars ahve been driven for 60+ years with owners and garagemen checking the fluid. Non-power brake Packards 35-56 have a m/cyl mounted down there too. Let's not make a problem where none exists

86'ish Ford explorer power brake unit on 56 Exec.

packardinfo.com/xoops/html/modules/newbb ... lat&order=ASC&type=&mode=0&start=10


Be sure to scroll back to page1 of above link.

packardinfo.com/xoops/html/modules/newbb ... um=3&post_id=156321#forumpost156321

Note that a 65 Mustng SINGLE stage cylinder will also fit directly to the Explorer power unit.

Or absolutely positively must have a dual master then use the Ford Explorer cylinder but u'll have to add a prop-valve in the lines.

Wendell Spreadbury in Texas, who is listed in the PAC directory, sells or used to sell a remote master cylinder refill kit which includes all needed hardware. I have seen them and they look to be a quality product. JWL