brake fluid change

[SkeksisNV]

Today I decided to bleed the brakes. Its been a little squishy since I bought the truck a few months back. As I started on the rear passenger side, the fluid came out a dark, rusty or muddy brown color and seemed very watery vs oily as I swirled it around in the jar. I imagine in the trucks 40 years of existence, the fluid hasn't been changed.

What is the best way to change the brake fluid? Should I stay with Dot-3 or go with Dot-4. From what I understand, Dot-5 is silicon based and shouldn't be used. What brand fluid do you guys recommend? Is there anything else in the brake system that I should check while the fluid is drained?

Thanks for the help.

[lolife99]

How is the rest of your brake system?
I would look at all the hoses before you decide to change fluid.
I would think DOT-3 or DOT-4 would be fine.

Here's a good article:
(I know it's a BMW,... but there's some goo info here)
http://www.dvatp.com/bmw/diy/brake_fluid_flush/

Also look at this:
http://www.workhorse.com/Portals/0/W...luid%20wip.pdf

[SkeksisNV]

Those are good articles. So I emptied out the reservoirs and wiped em clean with a paper towel and filled em with some DOT-3. I then started at the rear passenger side and bled them until the fluid ran clear with no air and did the same on rear-driver/front-pass/front-driver. The brakes seems to work a little better but I am still running into a issue I think.

The pedal will go about 3/4 way down before anything, then it feels like it wants to brake hard. Any idea what this could be? The front brakes I replaced along with calipers and rotor. Rear probably needs a total overhaul. I haven't been brave enough to pull em off and check yet.

[cparman]

Please go back to the basics. Pull all four wheels and inspect the brakes, clean and adjust all four wheels ( rears if you have front discs) THEN, bleed the system. A low pedal can be from brakes out of adjustment, or something wrong inside the master cylinder. I am a big fan of replacing the brake fluid in our old trucks. Brake fluid is hydroscopic SP. Meaning that it will absorb water, hence the rusty/mud that first came out of your bleeders.

[henri_auzinet]

Its good to change the fluid periodically to avoid corrosion in the brake system.

[Tx Firefighter]

New hoses are a good idea. You can get them for 10 bucks each or thereabouts. The'ye rubber and they're 40 years old. Think of the safety aspect. I swap them right away on every truck that I do.