changing brake fluid

[Boots]

Are you ever supposed to drain all of the brake fluid? I'm going to be installing new extended brake lines tomorrow and was just wondering. I know how to bleed the brakes and that there is a special procedure on the comanches, but I've never heard of any one draining all of the fluid. If you are supposed to, how do you do it?

 

thanks :wrench:

Chad

[jimoshel]

It's a good idea but most people don't do it because

1. It's a PITB and

2. They just don't think about it.

Brake fluid absorbs moisture. Eventually it gets enough to rust the system, and in a cold climate can freeze, no brakes. Remove the MC cap and rub your finger across the bottom of the cylinder. Gunk! I don't change the fluid just to be changing it, but whenever I work on the brakes for some reason i change the fluid and if it's really bad flush the system. Do it the same way you would bleed the brakes. Open the bleeder valve and pump the pedal until clear fluid comes out, or if you have a pressure tank, use it. Make sure you don't let the MC run dry.

[Boots]

So I just keep bleeding and bleeding and bleeding until the fluid looks new? So DON'T drain all the fluid then fill it up right? :hmm:

 

thanks

Chad

[maddzz1]

Yeah, Bleed each line until clear fluid comes out. DO NOT let the MC run dry or else you will have to bench bleed the MC too.

[05mxdiesel]

When I bleed brakes I use a turkey a baster to suck all the fluid out of the master cylinder and fill it back up prior to bleeding. This helps especially when starting out with rear lines since it takes a while to get fresh fluid out of of the bleeders.

[Eagle]

When I bleed brakes I use a turkey a baster to suck all the fluid out of the master cylinder and fill it back up prior to bleeding. This helps especially when starting out with rear lines since it takes a while to get fresh fluid out of of the bleeders.

:agree: This.

 

Why pump more of the crappy old stuff through the system? Siphone the old gunk out of the reservoir, refill with new joy juice, and save a lot of bleeding.

[jpdriver1]

pressure bleed set up helps alot --- can email the instructions for building one out of a garden sprayer if anyone needs it --

[Boots]

pressure bleed set up helps alot --- can email the instructions for building one out of a garden sprayer if anyone needs it --

 

I would appreciate that. :D

[Boots]

When I bleed brakes I use a turkey a baster to suck all the fluid out of the master cylinder and fill it back up prior to bleeding. This helps especially when starting out with rear lines since it takes a while to get fresh fluid out of of the bleeders.

:agree: This.

 

Why pump more of the crappy old stuff through the system? Siphone the old gunk out of the reservoir, refill with new joy juice, and save a lot of bleeding.

 

But I can't take it all out right? Because I'm not supposed to let it go dry, right? :dunce:

[jpdriver1]

what it does is supply fresh fluid as the old is pushed out --- email enroute

[Eagle]

When I bleed brakes I use a turkey a baster to suck all the fluid out of the master cylinder and fill it back up prior to bleeding. This helps especially when starting out with rear lines since it takes a while to get fresh fluid out of of the bleeders.

:agree: This.

 

Why pump more of the crappy old stuff through the system? Siphone the old gunk out of the reservoir, refill with new joy juice, and save a lot of bleeding.

 

But I can't take it all out right? Because I'm not supposed to let it go dry, right? :dunce:

Yes, you can take it all out. A turkey baster will never suck fluid up out of the orifices in the bottom, all you're doing is emptying out the cruddy old fluid that you would be pushing through the lines to dump anyway. Suck the reservoirs as dry as you can get them, wipe up the gunky residue with a clean rag, then fill with clean brake fluid and bleed normally. Once you start bleeding clean fluid through the lines, THEN it's important not to let it go dry or you'll be letting air into the system.