later model power brake clyinder on Packard

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later model power brake clyinder on Packard

Post by Packards42 » Wed Sep 09, 2009 1:32 pm

I like to increase the braking on the 41 limo, will any of the early 1950 master clyinders bolt up.


i rather stay Packard than go to a mid 50's aftermarket ford or chevy setup.

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Re: later model power brake clyinder on Packard

Post by dmdelavan » Thu Sep 10, 2009 5:34 am

While I can't answer your question I can say that the brakes on my '40 limo are fine. Aside from the normal adjustments and such(and I'm assuming your brakes are the same as mine) the primary and secondary shoes are the same size which was not standard industry practice but the way the car came. Proper dimensions are given in the owner's manual. I would check this as well as their general operation before doing anything more drastic. I will also mention that silicone brake fluid has been in the system for well over thirty years.
Don Gutting

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Re: later model power brake clyinder on Packard

Post by 39SixSedanMan » Tue Sep 29, 2009 9:42 am

As a former brake systems engineer, I would recommend caution when considering the addition of a power booster / master cylinder system. As a safety minded engineer, I too have considered such a change to protect my car, but more importantly, to protect myself and my passengers. If a system from the later 60's is chosen, you could also benefit from a dual hydraulic system, as mandated by law.

The concern is that many brake boosters combined with master cylinder, can produce pressure in the range of over 1800 psi and may be beyond the pressures that the wheel cylinders can handle. Further, you may not find this out until you are in a panic situation, stomp on the brakes and cause the failure due to the high pressure on the cylinders.

Modern systems carry a test requirement called Burst Level, which means the brake system equipment is subjected to a specified pressure beyond the normal range. To pass the test, the system must not leak and must remain functional.

I don't personally know the ratings of those systems of the 50's and I am not saying it would not be safe. I can only caution you to the physics that must be understood.


Dave Czirr
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Re: later model power brake clyinder on Packard

Post by Dave Czirr » Tue Sep 29, 2009 10:49 am

In concur entirely, those brakes should be much more than adequate. If you feel they aren't, I'd pull the drums and in addition to making the normal inspections, I'd see if you're getting full shoe contact with the drum. Some folks are inclined to play with the eccentric anchor w/o knowing what they're doing and not bothering to read the service information.

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Re: later model power brake clyinder on Packard

Post by Packards42 » Fri Dec 03, 2010 3:06 am

The break are like a lead coffin. I can upgrade the cylinders to modern to be on the safe side. no problem doing a burst test, I do that with 200 mile miles at work all the time. It the early 50's Cadillac has a inline brake booster available. those are about 200 dollar full restored. I live in the mountains and do not trust these brakes at all.

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Re: later model power brake clyinder on Packard

Post by Adam » Mon Dec 06, 2010 1:52 am

This does sound very odd !! The standard system, when working correctly should give perfectly good brake performance and exemplary for a car of this era.

If your brakes are not effective, then I would strongly recommend that you start by fully overhauling the entire system, including rebuilding the standard master cylinder. If you are lacking friction, although you have a good pedal, I would also replace the linings, regardless of the state of wear. You should also look very critically at the flexible hoses, as these can become restricted if they breakdown internally. Check that the metal brake pipes have not been crushed somewhere too.

In short, I suggest not changing the system until you KNOW that it is completely up to the original specification. Otherwise, any mods may be masking an fundamental fault.

I have a 1935 Chrysler Airflow, with a similar hydraulic brake set up. It will achieve 90% efficiency on the annual brake test and easily lock the wheels on the road. I drive in modern traffic with complete confidence, so I am concerned that there is a fault on your system that needs investigation.

Hope this helps
"Do not underestimate the English cousin.....they are not as stupid as they look!" - Signor Altabani in The Italian Job.

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