What Is Pressure Bleeding

Pressure bleeding a brake system is done using air pressure trapped inside a tank. Pressure bleeding is quick and easy because of the following:

• It does not require an assistant.
• It maintains a constant pressure in the system.
• It keeps the master cylinder full during bleeding.

Source/More Info

What's Needed

A pressure bleeder. You can either buy one or be a badass and DIY. I'm awesome, so I diy'd, here's my finished product:



A catch can of some sort:


Some Fluid:


And of course anything needed to lift the car, remove the wheels, and correct wrenchs for the bleed screws. You'll also need a turkey baster with some hose.

Doing The Bleed

Get the car up in the air on jack stands, remove the wheels, and fill up your pressure bleeder with a liter of your fluid of choice. Remove the rubber gromets on your bleeder screws at each corner of the car.



Grab your turkey baster and suck out the old fluid from the resivor.

Do not connect your pressure bleeder, simply hold the line above your resivor and give the pressure bleeder a few pumps to so that you fill your resivor. Since you just sucked out the old fluid with the baster, you need to fill it back up with new fluid. Once fluid has filled to an acceptable level, connect and pressurize your master cylinder. It seems like 12-13psi was the sweet spot. Maybe somebody can chime in with the correct pressures (I'm looking at you Maven). I know some German cars require some absurd pressure. Warning: Too much pressure and you may **** **** up.



Start with the passenger side rear bleed screw, connect your catch can to the bleeder screw, and crack the screw open. Brake fluid will start to flow and will eventually come out clean, once it does, close the bleeder screw. In my case since I'm using ATE Super Blue, my fluid changes to blue. Now move on to the drivers side front and repeat these proceedures. Be sure to keep an eye on the pressure of the pressure bleeder bleeding from corner to corner. (Remember, sequence is Passenger Rear, Driver Front, Driver Rear, Passenger Front SOURCE)

Initail screw crack:


2-3 Minutes later:


Yea, my fluid was already clean looking, but a tester yeilded 3% water content.

Note for the Turbo Cobalt, there are two bleed screws on one caliper for the front Brembo's.

Both do need to be bleed. My best guess was outside first, then inside.

Now the hard part, the clutch bleed.

It's bleed screw is buried in here:


Zoom, enhance!


It's easier to get at the bleeder screw from the bottom of the car. Check the pressure on your pressure bleeder, run your catch can hose, and crack that screw open to bleed!

Now that you've bleed all four corners and the clutch, release the pressure on your pressure bleeder, and make sure you're within the min/max lines on the resivor. I had a little bit of new fluid left over at the end, so 1 Liter was perfect for a full system flush.

Thanks to Caddyscat/Heliscat for taking awesome photos, Google, phatnackySS, & Lubify

LINK to the full set of hi-res photos.

 

Approved.

 

i need to do this..my brembos will be here friday

 

Awesome write-up. I'm all over this. My pedal is squishy and my dealership won't fix it. Thanks!!

 

what size tubing did you use to make a good seal on the bleeder screws?

 

OP, is that a replacement brake fluid reservir cap from the dealer or a universal type one from the auto parts store? I've been thinking of doing something similar since the motive bleeder is so damn expensive. Now I jsut need some free time to make this.

 

I just made one today... I used the HELP! Universal GM Cap #42042 (be sure to fill in the groove on the cap with some RTV or it wont pressurize) and the Gasket #42072. For the bleeder screws on the LS, its a 1/4" Inner Diameter. I got that from ACE for $0.50/ft.

 

I believe 1/4" ID (inner diameter) is the correct size. I used 3/8" ID and it was too big, but fit over the hex bolt part enough to make a seal. I'm still going to get 1/4" ID tubing tomorrow and do it right, and make a stab at the clutch.

 

I just pressure bled mine and I'm having very slight seepage at the threads on the bleeder screws.. I tighten them down well and still nothing seems to work. Anyone have this problem?

 

If you have an automatic you only need to bleed the 4 brakes correct? I know I don't have a clutch (or ABS for that matter), but I just want to make sure I don't miss something else.

 

sub'd

 

sub'd awesome right up!

 

oh thats a hardass DIY-selfer pressure bleeder mechanism. Should sell em on ebay lol! sub'd

 

Still looking for an answer. Bleeding my brakes tomorrow. I only need to worry about the 4 brakes since I don't have a clutch/abs correct?

 

wow awesome write up!

 

click good howto!

 

will that universal cap fit an 08 SS? i went to pep boys today and get everything to make this and they dont have a cap, nor does my other local auto parts store.

 

nice

 

To much pressure you will blow the seal on the throw out bearing fyi

 

nice DIY! I know with my STi I had to bleed inside 1st then outside.

 

Nice writeup.

One correction though:

Per the Brembo service manual, bleed the inboard side of the caliper first, then the outboard. Otherwise, you may get trapped air on the outboard side of the caliper.

 

Don't mean to bring up a dead thread, but I am doing this shortly but I plan on using my air compressor set to 15psi in place of the pump/jug mechanism. Just going to fill the master cylinder reservoir and then pressurize it from the compressor. The downside to this is I have to be careful to keep the reservoir from emptying entirely. The upside is it's cheap and easy to assemble.

 

any one know how to bleed these like brand new. i put new ones on and i got a brake pull. thinking theres air in them still just woundering if you bleed out both sides. i did a gravity bleed on the inside bleeders and normal pump the brake bleed on the outside bleeder

 

Need this

 

So if I understand it right, there is brake fluid in the sprayer and it goes (via the tube) into the master cylinder's reservoir under pressure, right? For some reason I though it would just be air pressure in there but then I saw the picture with the fluid in the sprayer...

Is it messy when you're done bleeding and remove the cap from the master cylinder? Or does the excess fluid drain back to the sprayer?

Either way this is a project I must do!