Hi!
I noticed while working on my brakes that the fluid is dark. It's kind of translucent greenish-black. (Huh? Is that color in the Crayola Crayon box?)

I've owned the truck for 4 years & about 35,000 miles. I'm guessing it is time to flush the brake fluid.

My question relates to gravity flushing of brakes. I don't have anyone available to pump the pedal to force the fluid out.

When I was a kid (last time I was in any hydraulic system), I would do this:
1) Remove 2/3 of the fluid from the reservoir
2) Put a tube on & open the farthest bleeder
3) Let fluid flow out, while adding new to the reservoir to keep it from going dry & sucking in dirt.
4) When fluid came out clean, close the bleeder.
5) Move on to the next farthest & repeat
6) Do the others

But, this truck has ABS. Do you think gravity bleeding will work, or will everything get stopped at the ABS pump?

Thank you for any ideas & knowledge you can share. It will be appreciated.
Paul

 

Well your ABS module will naturally let the fluid pass through the module when the ABS is not engaged and operating to pulse your brakes. So, gravity bleed should work I suppose. I wouldn't drain any fluid out of your reservoir though. Just top it off and wait. Draining any fluid out of there wont help you any, it'll all flow through eventually. Just don't let any air get into the system ... It's a pain in the butt to get all the air out again, and you'll most likely need a helper.

You can also take it to a shop and pay to have the lines flushed. They should have, at least my work has, a pressure bleeder that puts pressurized brake fluid through the cap of the reservoir. All they have to do at that point is go crack each bleeder until it flows clean and then that's it.

 

Thanks, NullHead!
I didn't realize that I could leave the old fluid while bleeding. Much less chance of getting distracted just long enough to let air go in. I get distracted easily. Old age?

If I'm not convinced it flushed well, or if gravity isn't working, or if I see chunks come out, I'll bite the bullet & take it to a pro. Best price I found so far was $140.00

The price sounds more than fair- After all, I'm not only paying for the technician's time & materials, but for their knowledge, experience & the expense of the equipment involved. Same holds true for any craft, trade or profession, mine included.