New owner here. 2004 4x4 XLT I've owned for 2 weeks(214Kmiles). I went to adjust the rear brakes today and found the DS wheel cylinder leaking pretty badly enough to soak the inner rim. I have the time and experience to fix this but also have a few questions. The brake fluid is toast, black and very dirty. The brakes still work just fine and no ABS light. My plan is to to replace the the rear shoes (since one side is soaked) and replace both rear brake cylinders. The drums appear fairly new. Is there anything should address up front other than a thorough pressure flush for the entire system, pads and rotors are both very good. If the brake fluid was that bad is it a good idea to replace the caliper pistons even though they aren't leaking at all and exterior rust isn't an issue? I have a Motive pressure bleeder and assume it's better to do the flush with the old components rather than after. The project is coming along great, AC working again, no codes other than a P1000 and B1600. I'm loving this truck so far, it just needs some love. Thanks

 

I would just bleed the system fully to get the old fluid out. The calipers are probably fine. Its pretty cheap, under 20$, so you might want to throw a rear drum hardware kit at it while you have it apart. The clean green and yellow and red springs look really nice before you put the drum back on.

I dont think the ABS light will come on for fluid condition, just a "low" condition.

 

I ordered parts yesterday and did get the hardware kit. I haven't done drum brakes in 30 years LOL I realized the teeth on the adjusting wheels were pretty worn down. With new brake parts maybe those self adjusters will actually work for more than a year. I have to try and straighten out that bed liner rail with a heat gun; I guess it got hot and had no where to go but up