How To Bleed the Brakes.

[Blackrider]

As Most of you probably know the Braking system on a vehicle is based on "Hydraulics" (Liquid does not compress) Now of course if you get Air in your brakes they will not work right.

How do I know if there is air in my Brake lines???
You will get a very spongy feeling on the brake peddle, remembering that liquid does not compress but air does. So when you are applying the brakes you are compressing the air in the lines.

Doing a "Dry Bleed" on our cars requires a pressure bleeder and OBD 2 Scanner.

If you don’t use an OBD 2 scanner you when you bleed the brakes you will be bleeding the positive side of the ABS System. The first time your ABS Valves open, guess what ??? More air.:( So you need a scanner to lock the ABS Valves open for the bleeding process.

Even changing the brake pads will require you to crack the bleeder screw, if done the right way. The reason you have to crack the bleeder screw is because, if you just push the piston back you are pushing the crud that is in the braking system back into the ABS valves. And this might cause an ABS Failure. This rarely happens but it is a possibility.

But to just get some air out of the calipers that might have got sucked in, you will first need 2 people. One to pump the brakes and one to open the bleeder screw. Start by first pumping the brake peddle about 10 time to build pressure, then open the bleeder screw, then once all the fluid/air has come out close the screw. Do not let up on the brake peddle before the screw has been close tightly or else you will suck in more air! The process should be continued until all the air is out and you get a steady stream of fluid coming out. If it is just a simple brake job, one to two times should do.

DONT DO'S!

As I said when DO NOT Let up on the brake peddle when the bleeder screw is open you will suck in a lot of air!

If you have high Miles/KM on you car and you have never opened the bleeder screw before be sure not to brake it off they tend to seas up after a wile.

If you are cracking the bleeder screw when the caliper is off DO NOT tip it upside down! Once again you will just suck in lots of air.


Vacuum Bleeders
If you only have yourself to bleed the brakes you could try a "Vacuum Bleeder” This tool will literally suck the air and fluid out of the lines. There is no pumping needed. The problem with these is that they tend to suck air from the outside around the threads on the bleeder screw. In my opinion they suck. But there may be better ones than I have use out there.

Hope this helps for all your Brake bleeding needs. It is a fairy simple process. Good luck
:thumbs:

[gagt17]

Originally posted by Blackrider

Vacuum Bleeders ... In my opinion they suck.

Isn't that the point?:p :thumbs:

[Blackrider]

Originally posted by gagt17
Isn't that the point?:p :thumbs:

In This case they "suck" Big time!:p

[Pixer]

When opening the bleeder screw, make sure you dont use the wrong socket and strip it, cuz GM cant get it out (cant drill into a caliper like on a regular screw and thus the charge you $400 for a new caliper.!!!!!!!!!!!! Man I got screwed:crying:

[pfofit]

If i can drill out a bleeder screw, Gm can. IF THEY WANTED TO.

I bet they made more money selling a $400 caliper than $0.40 cent bleeder screw. Labour is the same cause ya normally have to remove the caliper anyway to drill and EZ it out. Easier angles, drilling upside down and remove all fillings before backing it out.

What was there reasoning for not drilling out?

thanks

[Blackrider]

BEcasue if you drill out you have to tap it and it ends up being bigger so the bleader screw will not fit.

[Molson]

not with an EZOut.

[pfofit]

Black rider. OH no not the threads.
The bleed screw only threads in for about 1/4 inch, the last 1/4" is narrower and has no thread. The bleeder already has a i/8" hole in it to top of the seat.

Drill/enlarge the hole to keep some wall or to the size of your EZ out (Reverse thread screw extractor). If its in there big time, a few seconds with the blue tip of a propane torch(expansion and contraction) and presto chango, the sucker is backing out. I always use the blue tip on any bleed screw that doesn't give on the first crack anyway, or if it is rusted so bad that the size is distorted.

Bleeder screws are softer metal than the caliper

[Blackrider]

Any Time that i have seen a Caliper drilled out it has failed I mean its worth a try but for the Sucess rate i have seen its not that good

[Green99GT]

so where does the scanner come in?

[Blackrider]

Originally posted by Blackrider
[B]Doing a "Dry Bleed" on our cars requires a pressure bleeder and OBD 2 Scanner.

If you don’t use an OBD 2 scanner you when you bleed the brakes you will be bleeding the positive side of the ABS System. The first time your ABS Valves open, guess what ??? More air.:( So you need a scanner to lock the ABS Valves open for the bleeding process. [B]



With the right scanner you have the ability to lock the ABS valves open so you can blead out the ABS system

[Green99GT]

i c and if you dont use the scanner it dosent work at well?

[Blackrider]

There is no Manual way to open the ABS Valves so you need to do it Via the BCM with a scanner. If you dont open them and you Bleed the brakes when your abs kicks in for the first time the system get a rush of air and you will probably have next to know clamping force. When i say a "Dry Bleed" I mean Not one drop of fluid in the system. If you are just changing pads or replacing a Caliper you dont need to do anything with the ABS

[Green99GT]

i know...thanks make since

[grandam01]

ok the bleeder screw is located where, on the caliper or near the master cylinder. this will be my first time gettin down there so... im a newbie with this.

[Blackrider]

ok the bleeder screw is located where, on the caliper or near the master cylinder. this will be my first time gettin down there so... im a newbie with this.
Each caliper has its own bleeder screw on it. there should be 2 screws the one that ataches the line and the other one look like its hallow (Because it is) thats the Bleeder screw

[grandam01]

cool thanks man, i appreciate it.

[Landon]

I learned somethign today, only to forget it tomorrow

[grandam01]

now heres a good one, my brakes are somewhat spongy, they don't hit hard, i think it might have been that way to begin with and im just hoping for better braking since i bought some ceramic pads. but yeah it brakes pretty good, just the peddle feels kinda mushy, all i did was a pad change so i don't know whats up.

[grandam01]

nevermind guys i fixed my own problem, all i needed to do was drive it around for a bit, today the brakes went back to normal, actually they are now even tighter.

[Badblack04GT]

anyone know what size wrench fits the bleader?

10mm is too loose, 9mm is too tight and 3/8" is too tight..


I replaced the back pads and rotors tonight, it was fine for a while then got spongy. :(