Flushing the brake system

[Alfonso Gomez]

I'm about to install speed bleeders on my 87 Coupe. The brake fluid is a nasty shade of dark brown so I am going to flush it all out and put in DOT 4 fluid. A friend of mine suggested that I buy a couple jars of alcohol and after getting the old fluid out, put alcohol in the reservoir and flush the system with alcohol before adding the DOT 4 fluid. He claims the system will be a lot cleaner. Anyone done that? Is it safe for the system. I already had brake failure due to fluid contamination and want a clean system before adding the DOT 4.

 

[HD2HVETTE]

Don't know how you could get all the alcohol out of the system. If any remained you could have a serious problem with flammability. Alcohol may also affect other components if any is left in the system. I wouldn't do it.

 

[Edmond]

I wouldn't use alcohol either. I would make sure to get plenty of DOT 4 and flush that sucker out until you feel that every drop in there is fresh fluid.

Brake fluid and brake lines are not something you want to mess around with. The consequences can be tragic.

 

[corvted]

You could use DOT 3 to flush out the old stuff then use the DOT 4 to finish it off. The DOT 3 is much cheaper then the DOT 4 (depending on the brand). Sometimes it really needs a good flushing when it is that bad.

 

[Hot Rod Roy]

I think flushing with DOT 3 is false economy. You're better off by knowing you have the best brakes possible. If you flush with DOT 4, you will easily see by the color change when the new fluid has replaced the old. If you flush first with DOT 3, you won't be able to see when the DOT 4 has replaced the DOT 3, so you'll probably use twice as much DOT 4 just to be sure you've flushed out all of the DOT 3!

By all means, don't flush with alcohol. You'll never get all of it out of the system. Alcohol is good for cleaning brake parts, but the cleaned parts should be dried of alcohol before reassembling the system. Alcohol has a very low boiling temperature!

S.T.W.

 

[corvted]

I think flushing with DOT 3 is false economy.

It was just a suggestion. The information came from a fine mechanic by trade. My personal mechanic did it to my corvette when I first picked it up. The fluid was so contaminated that he went through over 45 oz of fluid (do the math) before it came clean. After that the dot 4 was used to reflush. With many of us that would like to save money anywhere we can the information seem justified and not to lead anyone wrong.

 

[redvett]

Unless you have a Tech 2 to toggle the ABS module you wont get all the old fluid out anyway. Only use recommended brake fluid in the system to flush it no alcohol it will damage the ABS unit.