[Solarphil]

I wanted to bleed my brakes prepping for the Festorics and O'fest next week at Laguna Seca, and I realized we really didn't have any good DIY posts on the process. Seemed like a good time to fire up the phone camera...

Here's the tools I used - from left to right:
1. Jack pads
1. Torque wrench - 140 NM / 103 Ft/lbs
3. 17mm socket and extension (if you have wheel locks you'll need a key too)
4. 11mm box wrench
5. Brake fluid. I use Pentosin DOT4 LV (low viscosity) because it's available locally, but run what you want, no flame wars needed here.
6. Reading glasses, because my eyesight sucks. YMMV
7. Pressure bleeder. I homebrewed this one, but if I did it again I'd probably just buy a Motive, it probably would have turned out cheaper. You definitely want an air chuck and pressure gauge on it.
8. Beer, because beer.
9. Good lighting
10. Gloves. I use mechanics gloves until I get the wheels off, then trade out for disposables for the rest.
11. Rags/paper towels. I don't have them in the picture, but trust me I use a lot of them.
12. 10mm socket to remove the plastic trim piece that hides the brake reservoir (not pictured)


You start the bleeding with the rear corner farthest away from the brake reservoir, so that's the rear passenger's side. Jack up that corner and remove the wheel. You'll see a small rubber-covered bump on the backside of the brake caliper, it looks like this but on the backside (this photo is of the front wheel, I started taking pictures after I was done with the rear).


Clean the crap away from around that fitting, then flip back the rubber cover with your finger. Fit an 11mm box wrench over the fitting, oriented at whatever angle you can turn it about a quarter turn counter-clockwise. Take a 2' long piece of 3/16" vinyl tubing (I picked this up at the local ACE hardware) and shove it over the end of the fitting.


Run the tubing down to a catch can - I use a 2 liter soda bottle that I drilled a small hole in the cap.


Under the hood on the front Driver's side there's a small plastic shield that you'll need to remove to gain access to the brake fluid reservoir - sorry, I missed taking photos of the panel but I will try to edit this post next time I work on the car. There's three 10mm plastic bolt heads poking up near the wipers, just turn them a quarter turn to loosen and then squeeze the plastic tab that's above the driver's front wheel to remove it, which will expose the brake reservoir in all its glory.

Clean the top of the reservoir with a cloth, then remove the cap. There's a small orange strainer inside, if you can get it out then remove it. I've been successful with that about half the time, but if I can't I don't worry about it. If you can remove it, suck out as much extra fluid as you can with a turkey baster. (I couldn't get the strainer off tonight, so I just let the first wheel run until the reservoir was almost empty, then refilled and ran it again). Don't let the brake fluid drip onto anything you care about, like paint - if it does, flush it off with lots of water or brake cleaner.

Here I've already attached my pressure bleeder. I like to put a bright light just behind the reservoir so the light makes it easy to see when it's getting close to empty or when I've filled it enough. IMPORTANT - note that there's a MIN marked on the reservoir. You don't want the level to get much below the min, or air will get into the system, you will need to flush it all out, there will be much gnashing of teeth, you will need to run to the store to get more brake fluid, and your quick project will turn into an all day sucker.


After tightening the cap on the pressure bleeder I pressurize it to about 15 psi.


I then open the bleeder screw a quarter turn. The first photo is the bleeder screw closed,

the second shows it opened and the brake fluid starting to flow.


I've noticed when using a pressure bleeder that air bubbles will get pulled into the 3/16 hose from around the bleeder screw. The first time I saw this, I thought I had air in my lines and I blew through gallons of brake fluid trying to flush it all out. Now I've realized that, unless I've worked on the brake system and have opened the line (or if you happen to have spongy brakes) there's probably not air in the line, just air coming in from behind the screw, and I don't sweat it.

Keep an eye on the reservoir, and if it gets close to the Min line then close the bleeder screw, release the air pressure, take off the cap and add more brake fluid (here you can see the orange screen that I couldn't get out). Lather, rinse, repeat.


The front brake calipers have two bleeder screws, one on the inside and one on the outside. I don't know if it makes a difference which one to do first, but I follow a mnemonic of Inside/Out to do the inside one first, cause that's what you do on an '02.


After you've done all 6 bleeder screws, top off the reservoir to just below the Max line and clean up. Make sure the rubber caps are back on each of the screws, and that everything's tight. Replace the plastic trim piece. I put my brake fluid funnel and turkey baster in a ziplock bag, so it minimizes the chances of getting brake fluid on things at random.


Put all the wheels back on if you haven't already, and check your torques after lowering the car to the ground. Drive the car a short distance and check the brakes, and make sure the pedal feels normal, not spongy or screwed up.

That's pretty much it, although I will offer free beers to the first person who can show me the best way to bleed the clutch.

[gtmax500]

Awesome! I just bought everything to bleed my brakes last week and was complaining how there wasn't a good DIY for our cars. This will be the first time I change brake fluid so I read up on the process and got the gist but man is this perfect timing. Just waiting on my EBC yellow pads to come in so I can do it all together. Thanks so much!

[overcoil]

Anybody use a wheel hub alignment tool for removing and installing wheel so you won't bang wheel against dust shield or caliper?

[Tpeterson]

Originally Posted by ScottSinger

Anybody use a wheel hub alignment tool for removing and installing wheel so you won't bang wheel against dust shield or caliper?

I do. Had to buy a 14 mm wheel stud to use because only 12mm alignment tools were available from my usual source. Works fine just has unnecessary threads on the end. This tool makes changing tires an easier one person job too.

[Tpeterson]

Good job. It's always nice to have vehicle specific DIY.Good tip about the double bleeders on the front brakes.

[ocN55]

ah shit, is it necessary to bleed from both nipples on the front? I only did the top.

[pikcachu]

Originally Posted by ocN55

ah shit, is it necessary to bleed from both nipples on the front? I only did the top.

if you don't, you only bleed one side of the caliper

[ocN55]

Originally Posted by pikcachu

if you don't, you only bleed one side of the caliper

Ah damn

Time to order some more ATE200...

Do I start from the back again or can I just bleed the 2 nipples I missed?

[pikcachu]

Originally Posted by ocN55

Ah damn

Time to order some more ATE200...

Do I start from the back again or can I just bleed the 2 nipples I missed?

Does the rear have 2 nipples too? else just do the front you missed as there should be no air in the rear and should have fresh fluid

[ocN55]

Originally Posted by pikcachu

Does the rear have 2 nipples too? else just do the front you missed as there should be no air in the rear and should have fresh fluid

Rears only have 1 on each caliper since its a 2 piston.

And yeah, no air in the rear. Thanks for the advice. I'll just bleed the 2 fronts I missed this weekend.

[dansu]

Great write-up! But I have to wonder, if you're using a pressure bleeder, why bother with filling the brake fluid reservoir? Just add your brake fluid to the pressure bleeder.

[overcoil]

Originally Posted by dansu

Great write-up! But I have to wonder, if you're using a pressure bleeder, why bother with filling the brake fluid reservoir? Just add your brake fluid to the pressure bleeder.

particularly with one person it's difficult to either site or depressurization the bleeder so that the reservoir is between the MIN and MAX lines when done.

[Pparana]

Originally Posted by dansu

Great write-up! But I have to wonder, if you're using a pressure bleeder, why bother with filling the brake fluid reservoir? Just add your brake fluid to the pressure bleeder.

The bottle would become contaminated, and messy, I use the same setup, I never fill the bottle.

I would call this a full flush, not a bleed. For bleeding I just use a one way valve off the nipple, a few pumps a corner.

[Solarphil]

In no particular order...

Years ago I got a Motive pressure bleeder for Christmas and I filled the bottle. It made flushing the brakes "faster" because I didn't have to stop to refill, but afterwards there was no good way to clean out the bottle. I also found out the hard way that mice in New Mexico are attracted to the left over brake fluid. My skin still crawls at that mess, and I couldn't even consider cleaning it enough to use again.

Now I leave the bottle dry and top off the reservoir after every corner. Technically slower but probably better in the end.

Only the front calipers have two nipples. I think you'd only need to flush the fittings you haven't hit yet, I don't think the fluid travels enough to mix enough to worry about.

And yes, flushing is really a better description than bleeding, but I always think of it as bleeding. Old habits ;-). The important part is flushing out all the old fluid and replacing with new. Brake fluid is hygroscopic and absorbs water, which decreases performance and leads to corrosion. Bad. New fluid good.

Offer's still open to anyone who can help answer the clutch question.

[ocN55]

Originally Posted by Solarphil

think you'd only need to flush the fittings you haven't hit yet, I don't think the fluid travels enough to mix enough to worry about.

^that response was for me right? lol about the 2 front nipples i missed.

Out of curiosity, did you find that there was barely any brake fluid in the reservoir when you opened the cap? I found that there was no fluid for me to suck out with a siphon. 6mt here...

[Solarphil]

Yep on the 2 front nipples section. I guess I should use the quote tool but on a tablet it's a bit of a PITA

I somewhat remember the first time I bled/flushed the brakes, I think I did get the orange screen out but still didn't get much out with the suction. I figured it wasn't worth sweating over, I just pressured the old stuff out down to the Min line, filled it, flushed then repeated on the first wheel.

[Tpeterson]

Originally Posted by Solarphil

Yep on the 2 front nipples section. I guess I should use the quote tool but on a tablet it's a bit of a PITA

I somewhat remember the first time I bled/flushed the brakes, I think I did get the orange screen out but still didn't get much out with the suction. I figured it wasn't worth sweating over, I just pressured the old stuff out down to the Min line, filled it, flushed then repeated on the first wheel.

How much brake fluid did you end of using? Is a quart/liter enough to have on hand? Never done it myself before.

[overcoil]

I'd have 1.5 liters on hand

[ocN55]

Originally Posted by Tpeterson

How much brake fluid did you end of using? Is a quart/liter enough to have on hand? Never done it myself before.

Originally Posted by ScottSinger

I'd have 1.5 liters on hand

You really don't need more than 1L.

If you need more than that, well then you kinda suck

Seriously though, I bleed all 4 corners and wasted some fluid by pouring it in a bottle (to compare color of new vs oem fluid) and am well above the min line.

[Solarphil]

I used 1 liter of Pentosin DOT4-LV, it was plenty. You can always buy two bottles just in case, as long as you don't open it you can keep it on the shelf for the next flush.

The LV is for low viscosity, which apparently BMW recommends for the ABS

[overcoil]

Originally Posted by ocN55

You really don't need more than 1L.

If you need more than that, well then you kinda suck

Seriously though, I bleed all 4 corners and wasted some fluid by pouring it in a bottle (to compare color of new vs oem fluid) and am well above the min line.

While it is true I suck at doing most things...a month ago when I did my brake flush I only used 24 ounces ( 2 of the BMW branded brake fluid containers ) the reason I would have twice as much on hand is if after doing the flush the brakes felt mushy on my test drive - I could easily repeat the procedure, and if that weren't necessary then I'd have enough fluid to every four months siphon out the reservoir only and refill.
I did find a YouTube video where the BMW tuner brake fluid instruction did say that sometimes the first flush leaves a mushy pedal, often you need a second flush.

This is the vid where he states, sometimes a second bleeding is necessary

[zipphreak]

Use denatured alcohol from the hardware store (lowes/homedepot) to clean the any of those brake bleeders or fluid catch bottles of brake fluid.. Works like a charm.

Pour in a little, swish it around, pump it through the lines... Wipe it down. Done!

http://www.homedepot.com/p/Klean-Str...SL26/100118908

Don't leave old fluid in it.