Flush brake fluid or just change Reservoir out?

[zedjr10]

I got a 92 accord ex coupe. Tomorrow a mechanic is changing out my front rotors(captive rotors) and pads for me and was wondering if i should pay him 60 bucks plus brake fluid to flush out my brake system. Or should i just change out the reservoir. How much fluid does reservoir hold in comparison to what is in the lines. The fluid am sure is pretty old and kind of black so something should be done. Am leaning to paying the 60 bucks but just trying to save some money. I can't jack up my car on all 4 jack stands so me doing it will be difficult. Hence why my choices are really just changing out reservoir or pay a mechanic to do it more proper i guess.

[Crankshaft]

You can open the bleeders to let the old fluid completely out of the system, then refill and start the bleeding process. As i posted a link on a different thread i read that DOT4 decomposses quicker than DOT3 therefore fluid change should be done more periodically. We often overlook brake fluid service, i recently serviced a car that had brake fluid with the consistency and color of coke syrup due to old age and deceomposition of the rubber hoses contaminating it severely.

[Fleetw00d]

Unless there is a leak from the reservoir, there is no need to change the reservoir. Just changing what is in the reservoir won't do much good, the problem with brake fluid that has absorbed water is that it can boil easier when it gets hot; this is more likely to happen at the wheel (calipers) than at the master cylinder. Suck as much fluid from the reservoir as possible, fill with clean fluid, then one wheel at a time (LR, RF, RR, LF), bleed the caliper until clean fluid comes out (make sure the reservoir doesn't get all the way to the bottom). You don't necessarily have to have all four in the air at the same time, and it doesn't necessarily all have to be done at once. A vacuum bleeder comes in handy instead of letting it drain all over the caliper and the ground. Even with a vacuum bleeder, I have found that having an assistant pump the pedal makes it go much quicker.

[F22Chris]

So blackish fluid doesn't necessarily mean bleeding the brakes. What causes the dark color is the carbon in the brake hoses. Check your hoses for cracks and stiffness. If they're brittle and old, change them. I've been taught to change brake hoses every 6-8 years, and to bleed them every two. I'd bleed them regardless in your case.

Also! There are tools that tell you if the fluid has absorbed enough moisture to validate a flush. You just dip the tool in the fluid, and a little light will tell you if it warrants a change or not. If it's above 2% water, it needs a change.

@crankshaft
Coke syrup?! Gross dude. I don't understand the level of neglect I work on myself sometimes.. it's weird to think dot4 decomposing faster. The only difference I knew of was boiling point.

[zedjr10]

You can open the bleeders to let the old fluid completely out of the system, then refill and start the bleeding process. As i posted a link on a different thread i read that DOT4 decomposses quicker than DOT3 therefore fluid change should be done more periodically. We often overlook brake fluid service, i recently serviced a car that had brake fluid with the consistency and color of coke syrup due to old age and deceomposition of the rubber hoses contaminating it severely.

Good to know. I can do front first then back in a flat parking lot or vice versa but cant raise all 4 wheels at once. I stick with dot 3 as i read that same thing(it isn't a race car). I was soon going to change the brake hoses into ss lines. Bought 2 32oz bottles of dot 3. First time doing this but this is pretty simple and only going to take 2 hours total i guess.

[deevergote]

So blackish fluid doesn't necessarily mean bleeding the brakes. What causes the dark color is the carbon in the brake hoses. Check your hoses for cracks and stiffness. If they're brittle and old, change them. I've been taught to change brake hoses every 6-8 years, and to bleed them every two. I'd bleed them regardless in your case.

Also! There are tools that tell you if the fluid has absorbed enough moisture to validate a flush. You just dip the tool in the fluid, and a little light will tell you if it warrants a change or not. If it's above 2% water, it needs a change.

@crankshaft
Coke syrup?! Gross dude. I don't understand the level of neglect I work on myself sometimes.. it's weird to think dot4 decomposing faster. The only difference I knew of was boiling point.

I'm one of those people that generally neglects brake fluid maintenance. I despise anything involving fluids, so I foolishly avoid stuff like that! I didn't even know about the brake lines being the cause of dark brake fluid. Good to know!

[illinois_erik]

i found flushing the system with a couple of cans of denatured alcohol released a lot of the same schmoo i found behind the pistons when i rebuilt the calipers.

[zedjr10]

i found flushing the system with a couple of cans of denatured alcohol released a lot of the same schmoo i found behind the pistons when i rebuilt the calipers.

That's good to know too. I did find a very good video for others who want to do this. https://www.youtube.com/watch?v=n1Nv...c#t=748.959542 .Just remember to keep the bottle above the hose your bleeding and the line not dragging i think is key(am going to watch this one more time). Good video on this. Eric the Car Guy is a second place on this video. I did see a beautiful 93 accord se at junkyard in Denver today and thought it had to be someone on here. Need to go back and strip off its abs unit.