Packard Forum Index » General

From post #39 above:
"There were never any Packards of any year with one or two lines entering the master cylinder except the '56 remote reservoir. Fluid and lines leave or exit the master cylinder"

Yeah, ok. Sure. Anything else u'd like to knit-pick tonite????? Actualy the lines neither enter, leave nor exit the master cylinder. The lines are connected to the master cylinder.

It was and is quite clear that the use of a vacuum pump was for evacuating the system. As I stated above "To disconnect a line and use a vacuum to evacuate the system....." I am clearly NOT referring to bleeding the system

As far as the suggested practice of flushing a brake system being "ridiculous", what is the basis of that statement? It is common knowledge that DOT alcohol based brake fluid is hygroscopic (absorbs water) and produces rust in iron based parts.

I am incensed at being called a nit picker, this forum is not for calling people names, it is for the sharing of information. If information posted is incorrect ( and I have done that at times) it is the duty of those who see it to discuss or correct it. Calling someone a name does nothing to get a car back on the road or provide safe motoring.

Alrighty Gents, no need to piss your names in the snow. Lets all lighten up a bit.

From the internet:

Why is Brake Fluid Flush Important?
The primary reason for a periodic brake fluid flush or brake fluid replacement is the chemical nature of the glycol based braking fluids. These chemicals are hygroscopic, that is they have a tendency to absorb moisture. With moisture absorption, boiling point of these fluids goes down and the efficiency of braking also gets compromised. When the boiling point drops, the brakes don't work properly in high temperature conditions or high braking situations. Fresh brake fluid is clear, while the one which has absorbed moisture is denser and less clear. This deterioration of braking fluid quality can be especially detrimental to anti-lock braking systems.

Many sites mention flushing from every 2 to 6 years. Keep in mind that most newer cars do not have vented master cylinders like most pre '66 cars do. The newer cars have a rubber diaphragm separating the fluid reservoir from the atmosphere, the primary source of damaging moisture
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MY ADDITIONS

In other forums that have been numerous instances mentioned of brake fade/failure mostly in the higher powered 55-56 V8's. Some has been blamed on BTV's or modern linings. Perhaps the decreased braking efficiency has been due to moisture in the fluid?

Yes. Moisture in the fluid. That's why i recommended using vacuum to eleminate any moisture that mite be left in the system after it has been drained.

The same vacuum process is generaly accepted and widely used method for air conditioning systems to evacuate moisture from the internal passages of AC systems.

**** As for frequency of draining and flushing the entire brake system there is no schedule of any kind outlined in the owners manual, FACTORY service manual, Motors, Chilton or anyother generally accepted authoritative source to perform any such 'draining and flushing'. Or at least none that i can find. ******

IF significant contamination is evident in any brake system then the wheel cylinders and/or master cylinder and/or other parts should be disasembled for cleaning and inspection. Otherwise a simple 'draining and flushing' is just a wasted effort.

BMW, whose factory brake fluid is DOT 4, has recommended for years (and perhaps still does) that brake fluid be flushed and replaced every 2 years. Whether other manufacturers recommend it or not I can't say. But I don't consider BMW's engineers to be bumbling fools.

I usually replace brake fluid every two years in all of my cars including the Packard. I generally use DOT4 which Volvo recommends for my 1983 242. I also use a pressure bleeder called a Speedibleed rather than the conventional method when possible.

I did not find the Volvo and BMW schedules, needless to say their army of engineers knows more about basic vehicle systems than I ever will.