Replacing brake fluid?
Thread Starter
Joined: May 2006
Posts: 3,974
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From: Spring Hill, FL
Replacing brake fluid? If I want to replace most of my brake fluid how should I go about this? Looking at working on my ABS delete and installing my braided lines this afternoon. Should I just unhook a line and start pumping or can this cause an issue? Or should I just work on it and as I bleed it enough new fluid will be in the system?
I don't know if there is much of a market for ABS blocks, but should I take it out first so that it isn't empty for the next owner?
How much should I have? I picked up a 64 oz. container the other day while in a parts store, will I need more if I want to try to change most of the fluid?
Thanks!
I don't know if there is much of a market for ABS blocks, but should I take it out first so that it isn't empty for the next owner?
How much should I have? I picked up a 64 oz. container the other day while in a parts store, will I need more if I want to try to change most of the fluid?
Thanks!
Generally, bleeding the brake system requires 2 people but if you have a brake bleeder vacuum pump you can do it yourself. Your description involving removing a line and pumping will introduce air into the system. 2 person brake bleeding is as follows; ensure the brake fluid resrvoir is full of brake fluid; with wheels removed (vehicle safely on jack stands), starting with pass rear, locate bleeder screw on the caliper, have your assistant pump the brake pedal (engine off) till it is hard and HOLD, you crack open the bleed screw and fluid will escape. Your assistant will note when the brake pedal is close to/on the floor (still holding, do not release pedal with bleeder open!) at which time you cinch/tighten bleeder screw closed. Your assistant may release the brake pedal now. You must top off the brake reservoir now to avoid the level getting too low and introducing air into the master cylinder. Should this occur, you may have to take the vehicle (tow time!) to GM and have the abs block "cycled" to remove the air! Repeat as many times as necessary for each wheel to get as much of the old fluid out. Repeat the entire process next with the dr rear, pass fr and last the dr fr caliper. It may be beneficial when doing the last bleeding (each wheel) to tap the caliper body to dislodge any small bullbles that may be clinging to the inner passages. New fluid without air will result in a firmer brake pedal while the engine is running/you are driving. Maybe not a lot but it should be noticeable. A brake pedal that is soft(er) means air was introduced into the system. DO NOT DRIVE. Start the process over until you have a reliably firm pedal.
You can bleed a system with a litre or slightly less.
I suck all the fluid I can from the MC by using a turkey baster or animal syringe.
This reduces the amount of mixed contamination of old and new fluid in the reservoir.
The pump - hold - open bleeder - close bleeder and repeat method is tried and true.
Recently, though I've been doing more and more stuff solo and have had good results using gravity bleed. Takes a while, but has been effective. Just stay on top of the level in the MC.
I suck all the fluid I can from the MC by using a turkey baster or animal syringe.
This reduces the amount of mixed contamination of old and new fluid in the reservoir.
The pump - hold - open bleeder - close bleeder and repeat method is tried and true.
Recently, though I've been doing more and more stuff solo and have had good results using gravity bleed. Takes a while, but has been effective. Just stay on top of the level in the MC.
i vote to install self bleeders on the calipers. my brakes hung for over a month without calipers. the lines were empty. i then filled and bled new SuperBlue in the system. i used self bleeders the last time i did my brakes and they turned out awesome. still start farthest from the mc and work to the closest one at a time.
