Brakes: Brake line Flushing.

[Aussie Hawk]

Apart from the cost saving, is there any other benefit in flushing a brake system with alcohol instead of brake fluid? It seems to me the extra work involved in getting all the alcohol out after the flush, you may as well flush the system with new brake fluid. I have system, (non Stude), to do over the weekend any suggestions greatly appreciated.

[StudeRich]

It just makes sense to me to use Alcohol because it has more "cleaning" capacity, dries fast and is much thinner than brake fluid to desolve more gunk.

The little bit that remains can be blown out with compressed air.

Now if the Brand X is equipped with a equilizer valve, a Hydrovac or other newer car stuff, I do not know the consequences.

[Aussie Hawk]

It just makes sense to me to use Alcohol because it has more "cleaning" capacity, dries fast and is much thinner than brake fluid to desolve more gunk.

The little bit that remains can be blown out with compressed air.

Now if the Brand X is equipped with a equilizer valve, a Hydrovac or other newer car stuff, I do not know the consequences.

Thanks Rich, food for thought. It's in my wife's '73 VW van - no proportioning valve or hydrovac, just a booster.

[WCP]

I just gravity bleed into a glass bottle thru clear tubing. You will see the change in fluid colour as the new comes thru and the bottle allows monitoring the amount of fluid bled at each wheel cylinder. I don't like the idea of flushing with any fluid other than brake fluid, unless the cylinders have been disconnected, due to differing viscosities. Putting alcohol thru a wheel cylinder is not a good idea IMO.

[Skip Lackie]

Agree with the above if you're just flushing out old, dirty fluid. But if the intent is to switch to/from DOT3 to/from DOT5 and replace the brake hoses and other rubber parts, then I would suggest using something that is both a good solvent and dries out quickly, like acetone. A little blast with compressed air leaves the insides of the steel tubing nice and dry.

[jclary]

If you think about it...all our Studebaker vehicles have very little volume of fluid in the brake system. The four wheel cylinders, master cylinder, and the small lines do not total up to very much. Theoretically, the fluid is rather "static" in the system and except for leaks, or in the case of the "bleeding" process when servicing the system, there is no circulation in the system. If you want to merely "clean" your system, you can break the lines at the master cylinder...drain it...and then take the lines loose at the wheel cylinders and blow out the lines from the master cylinder to the disconnected lines at the wheels. Remove the wheel cylinders, and service them.

Doing it in this manner, prevents you from blowing all the gunk that has accumulated in the master cylinder through the rest of the system. The master cylinder contains the largest volume of brake fluid in the system and is vented to atmosphere. Therefore, it has the greatest capacity to acquire moisture, rust, and contaminants. Flushing that stuff through the system in an effort to clean it could spread the stuff throughout the lines. That's not all bad if you do it completely...but why take the chance if you can break the lines at the back of the master cylinder and dump the goop there instead of blowing it to the wheels?

When I converted my Land Cruiser to DOT 5...I rebuilt the master cylinder, replaced the steel lines, flex lines, and wheel cylinders. Since then, I have not had problems with corrosion, dragging, and wheel lock-up that plagued the car before.

Nothing I know of makes me less likely to drive one of my vehicles than to be unsure of its brakes. My business coupe has sat for more than a year because it needs brake work. I also need to freshen up the front suspension. This is a case of where my lack of experience (and confidence) in tackling the suspension, has led to problems with the brakes due to neglect. My drafty man cave leads to wheel cylinder corrosion when the cars sit for long periods of time. These old technology brake systems need to be exercised to ensure proper operation.

No amount of "flushing" will help a wheel cylinder that corrodes under the dust boot behind the piston where the steel actuator pin contacts the aluminum brake cylinder piston. When small amounts of DOT 3 fluid leaks into this area...interacts with moisture laden atmosphere along with dissimilar metals (aluminum, cast iron, and steel)...a chemical stew resulting in the corrosion and inoperative wheel cylinder is a natural consequence. When this happens...replacing or rebuilding the cylinder is your only options.

[WCP]

I failed to mention in my previous post, that most readily available alcohol contains water, maybe 10 -30%. Consider that the air being used to blow out the lines also contains water, there is a high likelihood that you will not be able to fully dry the lines. As Skip points out, a highly volatile dry solvent is mandatory if using compressed air as the drier after flushing disconnected lines.