Adding Brake Fluid to Original System ?
 

I need to add brake fluid to a original 71 C20. It has power disc/ drum setup and is all original. The master cylinder has never been low and never had problems in over 10 years of owning the truck. Question, the fluid is dark and I figure it's time to flush it out. Good idea or just top off ? What type of fluid to I use ? Flush it ? Thanks it's hot and I got a big fire close by the ranch to watch out for too...:metal:

Re: Adding Brake Fluid to Original System ?
 

a auto part store should be able to tell u what it calls for but there can only be one/ dot 3 or dot 4 brake fluid. they do sell a universal. also if there are no leak I would check your brakes to c if there time to replace. but problem areas for leaks are wheel cylinder in drums leaks by firewall booster. to look. if u never flush your fluid and u don't know how to its good to learn. just make shure all air is out of the system. BE ABSOLUTELY CARE FULL with brakes and airbags./ there are plenty of how to out there.

Re: Adding Brake Fluid to Original System ?
 

Flush it. DOT3.
DOT3 attracts water so you're supposed to flush it every couple years. Same with newer vehicles.
You can use a turkey baster or big syringe to remove fluid from the res. and then bleed til clean fluid comes out.
DOT3 brake fluid eats paint so clean it up.

Re: Adding Brake Fluid to Original System ?
 

x2

Re: Adding Brake Fluid to Original System ?
 

Thanks guys ! Flushing with a Dot 3 ! Amazing GM engineering ,44 year old truck and still running factory brake system.:metal:

Re: Adding Brake Fluid to Original System ?
 

Things like brakes are over engineered to be ultra reliable because people die if they aren't and GM doesn't want their brand to be known as the coffin on wheels.
Trust me GM didn't switch to front disk brakes as a standard feature out of the kindness of their hearts. :lol: