'95, bleeding OLD brake fluid and ABS

[rickb928]

I'm really due to replace the front calipers, will do the rears as well, but a question.
My Ex has 310k on it, and the brake fluid in the reservoir is not clean - dark, had filmy stuff in it, last pad change I siphoned it nearly dry and filled new, but the new is of course discolored. Bleeder screws are rusted in place. My shop wants to replace calipers etc and bleed/FLUSH the brakes, but bleeding what's in there scares me. What will happen if this fluid gets flushed through the ABS system? I don't feel like doing a brake job and buying a $1200 ABS block cause my shop guy says it won't be a problem. I learned my lesson flushing my tranny at 236K+/-, that was the end of that.

So, flushing this probably ancient (150K+) fluid through the ABS, no problem or not a good idea, and if not a good idea, how do ya ever flush the brakes? Is there a bypass, or do I pull off the ABS lines and then reconnect them?

ps- ABS works FINE, no problems, no codes, stellar system. I don't need to clog it up and go through that.

Thanks!

 

[jremington59]

I think the fluid in the ABS would be as filthy as the rest.

What if you were to spray the bleeders with PBblaster and get them freed up and then loosen all the bleeders and let them gravity bleed out? You'd just have to make sure you kept the rez full.

 

[rickb928]

I've tried the PBBlaster and everything else, even Coca-Cola. One front and one rear are just rusted in and hopeless. Calipers aren't that expensive, it's the inevitable bleed/flush that worries me. And the caliper piston boots on the fronts aren't in good shape, etc., they are old.

I'm still concerned about flushing the ABS - sure the fluid is old, but there isn't much exchange within the system, so a flush is a 'major event' to the system components.

 

[my pos mounty]

Your brake system shares the same fluid, so if the fluid in the res. is dirty, its just as filthy in the ABS pump. Flushing that crap out is a great idea. It will get all the garbage that is present in the fluid out. Brake fluid will absorb moisture in the air over time and it can actually start to rust your brake components from the inside (internal rust is what seizes calipers). So if you can stop the rust from forming and can get the contaminated fluid out, there is no down side, its all good.
I would go buy the calipers, replace them and flush the entire system as soon as I could.