DIY - Brake Bleeding, Adding/Replacing Brake Fluid Procedure

[Dackelone]

There is one BIG important reason in using a pressure bleeder like Motive's. When you use the old fashion way to bleed the brakes, by having someone pump up and hold the pedal... all it takes is for them to go too deep - stepping down on the brake pedal travel. To ruin the brake master cylinder seals. You won't fnd this out until much later though.

The brake master cylinder walls get polished over time and use of the brakes. Normally the bottom half of the brake master cylinder is all rusty. Any good metal rusts (just look at our brakes when the car gets parked in the rain!). So... when you have your assistant - pump and hold the brake pedal... and he/she goes too deep down the pedal stroke... the rust down there will cut the ruber o-ring seals in the cylinder. A few thousand miles later you'll be sitting a T-light and notice why you brake pedal is slowly going to the floor! This is because the seals are leaking b-fluid internally. Nothing you can do but to replace the master brake cylinder. This is why I like using a Brake Pressure Bleeder - like Motive's. Also bc I can work alone on my car. But mostly it is for the safety aspect.

Also.... Always use NEW brake fluid. Even if its just a few months old open can - do not use it! Brake fluid is like a sponge... it will absorb water. In water in the air like in humind climates.

Btw... I always put brake fluid inside of my Motive pressure bleeder. I also use a new clean turkey baster to suck up - excess brake fluid from the B-fluid resivior after the job is done. Also you should have some "Brake Cleean" on hand to spray down/off any spilled brake fluid off painted surfaces and wipe clean. brake fluid and paint do not mix well!

Good Luck
David

[kwanzto]

FYI - both the Brake and Clutch bleed valves on my 08 135i used required an 11mm wrench/socket.

[Dackelone]

Yes... most German cars use either 7mm or 11mm bleed screws/nipples. You should use either a 12 point ring wrench or a flare tool - so you do not strip the bleed screws. You DO NOT want to use an open ended wrench.

IF it has been awhile since you last bled your brakes - you might use some sort of penitrating oil on the bleed screw first.

One other thing that I think everyone so far has taken for granted... is to state the (obvious) bleeding process. You want to first bleed the longest brake lines. So that is: Right Rear, Left Rear, Right Front, Left Front!

Using a pressure bleeder makes this whole process soooo much easier. But you do not have to use one.

Good Luck,
David

[DBFIU]

Originally Posted by Dackelone

There is one BIG important reason in using a pressure bleeder like Motive's. When you use the old fashion way to bleed the brakes, by having someone pump up and hold the pedal... all it takes is for them to go too deep - stepping down on the brake pedal travel. To ruin the brake master cylinder seals. You won't fnd this out until much later though.

The brake master cylinder walls get polished over time and use of the brakes. Normally the bottom half of the brake master cylinder is all rusty. Any good metal rusts (just look at our brakes when the car gets parked in the rain!). So... when you have your assistant - pump and hold the brake pedal... and he/she goes too deep down the pedal stroke... the rust down there will cut the ruber o-ring seals in the cylinder. A few thousand miles later you'll be sitting a T-light and notice why you brake pedal is slowly going to the floor! This is because the seals are leaking b-fluid internally. Nothing you can do but to replace the master brake cylinder. This is why I like using a Brake Pressure Bleeder - like Motive's. Also bc I can work alone on my car. But mostly it is for the safety aspect.

Also.... Always use NEW brake fluid. Even if its just a few months old open can - do not use it! Brake fluid is like a sponge... it will absorb water. In water in the air like in humind climates.

Btw... I always put brake fluid inside of my Motive pressure bleeder. I also use a new clean turkey baster to suck up - excess brake fluid from the B-fluid resivior after the job is done. Also you should have some "Brake Cleean" on hand to spray down/off any spilled brake fluid off painted surfaces and wipe clean. brake fluid and paint do not mix well!

Good Luck
David

Thanks for the advice.

[JimD]

Maybe Dackelone has a prior experience that causes him to be concerned about a rusty area of the master cylinder but I have bled brakes in some pretty old cars that had infrequent brake fluid replacement and I have never damaged a master cylinder bleeding the brakes. I've torn apart wheel cylinders for drum brakes that were old and found corrosion or deposits or something but it was grey/black, not red like iron oxide (rust). If you change your brake fluid regularly, I see no reason to expect any rust on your master cylinder.

I think the other reasons for a power bleeder are valid but I don't know about this one. I've never seen a problem that it would be fixing from the master cylinder standpoint.

I would also put the fluid into the res. instead of the bleeder. The disadvantage is you have to add some more each wheel. The advantage is not having to clean the bleeder nor run the risk of running out of fluid and injecting air into the lines.

Jim

[wkndracr]

Originally Posted by Evolution Racewerks

Also, if you are changing stuff out like brake lines or upgraded brakes, might be a good idea to bleed the DSC. The procedure to do this via BMW is to pressure bleed all 4 sides until no more bubbles. Then repeat process, but this time, open the valve and pump the brakes 5 times.

What exactly do you mean by this? Which valve do you open, and is this process for each wheel? Would this procedure even be necessary when just upgrading to higher temp fluid without opening up the hydraulic system?

[Dackelone]

Originally Posted by wkndracr

What exactly do you mean by this? Which valve do you open, and is this process for each wheel? Would this procedure even be necessary when just upgrading to higher temp fluid without opening up the hydraulic system?

I think "Evolution Racewerks" meant the ABS/DSC valve body. the all alloy block near the brake resivoir. There are no bleed valves, just brake lines going into and out of the "block". The way you would bleed it would be to loosen EACH metal brake line going into and out of the valve body.

I would never try that... bc you are just ASKING for trouble - stripping a brake line nut! But to each their own.

Using a pressure bleeder like the Motive would do the same thing... bc you would "move" that old brake fluid out of there... by running a few liters thru the system. It's way less risky too. I always bleed more fluid than necsarry. Norammly I run thru the sequence twice. RR, LF, RF, LF. Then repeat te bleed all over again.

Good Luck,
David


Here is a picture of the ABS valve body block next to the brake res!


Incase someone is curious as the the VR, VL, HR, HL stampings on the valve body... thats German for:
VR = Front Right
VL = Front Left
HR = Right Rear
HL = Left Rear

Hinten = Rear
Vorden = Front

Rechts = Right
Links = Left

[Dackelone]

Ok, here is my little DIY brake bleeding procedure…

Tools & Supplies needed

*Motive (or similar) pressure bleeder, with European screw on cap.
*Two liters of DOT-4 Brake fluid.
*11mm, 12point box-end ring wrench.
*6mm inner diameter CLEAR tubing/hose. Found at any fish supply
shop. 1 meter will be more than enough!
*four Jack stands and a good quality floor jack.
*17mm ½ drive socket and torque wrench.
*small ½ liter bottle to catch old brake fluid.
*Brake Clean spray
*shop towels
*new and clean Turkey Baster(Sp?) – to suck out brake fluid. Don’t
forget this important tool!


I always use DOT-4 or Super DOT-4 brake fluid.

DO NOT use DOT-5, bc this is a synthetic brake fluid and it is dam hard to flush all the old fluid out to use this DOT-5 stuff. It can cause more harm than good. So just stick to DOT-4 fluids.


First thing you want to do is put the car level on four jack stands and remove all four wheels. You can also just do ONE wheel at a time – but this is more of a PITA if you ask me.

Open the hood and access the brake res plastic cover (remove it). Its just in front of the driver, under the hood, up by the wiper arms & hood hinge.

Add one liter of fresh/new bottle of DOT4 brake fluid to the Motive pressure bleeder. Have a 2nd liter of brake fluid handy incase needed later on.

Unscrew the brake res cap. Have some paper shop towels handy to place under the dripping brake fluid cap.

Screw on the motive euro cap. Pump up the Motive to only 10 psi! Do not go too crazy with pumping up the pressure bleeder. You can easily blow off the reservoir housing on older cars!! Ask me how I know this!! Makes for a BIG mess. So stay under 10 psi!

As you pump up the Motive, fresh brake fluid will enter and fill the brake reservoir fully.

Go to the RIGHT REAR brake caliper and find the bleed nipple/valve. Remove the dust cap. Slide on that 6mm clear tubing you bought from the pet/fish supply store. I use about 15 niches or so long piece of hose.

Now slide your 12point ring/box end wrench over the hose and onto the bleed valve. MAKE SURE the Motive is hooked up and pressurized to 10psi! OPEN the bleed valve and start to collect the old fluid with your handy container. I use an old one liter Gator-Aid bottle.

You will notice the old brake fluid start to fill your catch can/bottle. You can even see air bubbles IF you have boiled your brake fluid in the past. THIS is why you want a CLEAR 6mm I.D. hose! Continue holding the valve open until the fluid changes in color from dark brown to the new brake fluid color (clear or light tan in most cases). Or blue ATE if you are using that stuff. I prefer normal clear fluid.

Sometimes I close the bleed screw. I will go and check the Motive for pressure and to check the fluid level. Then I go back to that wheel and open the bleed screw again – just to make sure all the air and fluid is gone. And re-bleed that caliper again.

Ok, move onto the next wheel. Remember: RR, LR, RF, LF!!!

Now you are almost done!

Release the air pressure from the Motive bleeder. Be careful when you are finished bleeding the brakes, you want to de-pressure the Motive FIRST and then unscrew the adaptor cap. You can de-presurize the Motive by unscrewing (counter clockwise) the pump handle(T)… S-L-O-W-L-Y!

IF you unscrew the Motive first from the brake res, you will be pouring pressurized brake fluid all over the place! De-pressurize FIRST!

Now use your (new!) Turkey Baster to suck out some new brake fluid. You will need to make room for the res brake fluid float sensor. Just look at the cap to see what I am talking about. There is a little MAX mark on the side of the reservoir to show you what the correct fluid level should be.

Ok, that’s about all there is too it. Its quite a simple process. One thing I should say is I have never bled the brakes on my 135i. In theory it should be all the same. The only thing I can think of is the front calipers MIGHT have two bleed valves. And inner and outer one. Porsche’s Brembos are like that. I do not believe there is any order you need to do on those. Someone correct me IF I am wrong.

Here are some photos I have from doing my CDV delete. Its all the same really.




Motive pressure bleeder with euro cap adaptor…


DOT-4 German brake fluid. The GOOD stuff!


Do NOT go over 10 psi or so! You will blow off the reservoir housing from the master cylinder!!



European cap adaptor – with fresh brake fluid going in!


Always have some CRC (or the like) Brake Cleaner on hand to wash away any spilt brake fluid!


ABS valve body…


Some 11mm 12pt wrenches – the bottom tool is only needed to bleed your brakes valves.

[stltri]

Was wondering how much bubbles are normally seen coming out of the valves..? And how much old fluid is collected per corner..? I've used the motive bleeder twice and I see lots of bubbles coming out of valves..almost like bubbles you see when you pour water from a bottle.. My question is that are these bubbles really from the lines or from around the neck of the bleeder valves?? I do track my car often. I use Ate blue alternating with yellow.

[Dackelone]

Originally Posted by stltri

Was wondering how much bubbles are normally seen coming out of the valves..? And how much old fluid is collected per corner..? I've used the motive bleeder twice and I see lots of bubbles coming out of valves..almost like bubbles you see when you pour water from a bottle.. My question is that are these bubbles really from the lines or from around the neck of the bleeder valves?? I do track my car often. I use Ate blue alternating with yellow.

The short answer is you need fresh/new brake fluid - bc you are boiling your brake fluid. I bet you have a soft pedal too.

You want to get out ALL the bubbles when you bleed the brakes. I normally take out about 200ml per corner. I do the entire car twice. Always start with RR, then LR, the FR and then FL. You want to do the longest brake line first - that is the reason for that order. This is for a LHD car ofcourse.

The reason why you are seeing LOTS of bubbles is because your brake fluid has been boiling. When the brake fluid starts to boil... air bubbles will be inside the brake lines. I would use a higher spec brake fluid IF your going to the tracke often.

Most track drivers will bleed the brakes before and after each track event! Over here in Germany... BMW AG says to replace the brake fluid yearly. For US spec cars,,, they say every two years.

Over here... when you go to get your car inspected by the TUV... they acutally take a sample of your brake fluid... and put it in this tester... to see at what temp it boils/flashes over. IF its too low a temp - they will fail your brake system and you will need to change out your brake fluid. Its wild over here to the extent they inspect cars. Luckyly, we Americans are exempt from the regular German TUV.


Dackel

[yawn]

An old thread I know, but on a RHD car, what would be the order of bleeding? Left rear, right rear, left front, right front - longest to shortest, right?

And where are these bleed nipples?

[Dackelone]

Originally Posted by sharkatron

An old thread I know, but on a RHD car, what would be the order of bleeding? Left rear, right rear, left front, right front - longest to shortest, right?

And where are these bleed nipples?

^^correct! As long as the brake master cylinder is on the RIGHT side of the firewall... on a RHD car... then yes, longest to shortest brake lines bled first.

So... RDH... LR, RR, LF, RF.

The bleed nipples are on the brake calipers. use some penetrating oil if its been a long time since they were last bled/opened. Also its best to use a FLARE wrench since it grabs all sides of the bleed screw(nipple) so as not to round off or strip it.

good luck,
Dackel

[yawn]

Originally Posted by Dackelone

^^correct! As long as the brake master cylinder is on the RIGHT side of the firewall... on a RHD car... then yes, longest to shortest brake lines bled first.

So... RDH... LR, RR, LF, RF.

The bleed nipples are on the brake calipers. use some penetrating oil if its been a long time since they were last bled/opened. Also its best to use a FLARE wrench since it grabs all sides of the bleed screw(nipple) so as not to round off or strip it.

good luck,
Dackel

Thanks!

[fredy]

ECS DIY.

[Kgolf31]

Originally Posted by Ian///M

As the brake & clutch are shared, does this process also bleed the clutch fluid, or is that a separate bleed?

Separate bleed. However just involves you crawling under the car and locating that bleed screw and loosening it. You can still use the pressure bleeder, if that is what you're asking.

[Kgolf31]

Originally Posted by Ian///M

Thanks. So to completely flush the system, both brakes and clutch should be bled? Seems by only bleeding brakes it will leave the clutch with old fluid.

I was looking at a vacuum bleed rather than Motive pressure bleed.

If you want to completely flush the system, then yes typically the clutch will need to be bled in addition to the brakes. The lines go to a common bank, so if you don't spend the time you're not really going to notice the difference with some old fluid cycling around in there.

(This is basically the case when it comes down to flushing/cycling the ABS while bleeding).

I don't like vacuum bleeding because you can create a suction too much where you create air within the system.

[Kgolf31]

Originally Posted by Ian///M

Noted, thanks. Went with the Motive Power pressure bleeder. How easy is the clutch bleeder valve to get to above the CDV?

Couldn't tell you, haven't crawled under my E82 yet.

The E86 is stupid easy, it is like 6 inches above the CDV. I would assume the same

[Dackelone]

Originally Posted by Ian///M

Noted, thanks. Went with the Motive Power pressure bleeder. How easy is the clutch bleeder valve to get to above the CDV?

Space is kind of tight up in there. The main problem is finding the right kind of wrench that will allow you to open and close the CDV bleed screw. With most wrenches you can only turn the bleed screw a 1/4 turn at a time. See the CDV delete DIY for more pics. My pics are on page 5, post #97...


CDV Delete/Replacement DIY
http://www.1addicts.com/forums/showthread.php?t=209440


Also when you bleed the cdv, do not over tighten it. Lots of guys have snapped that bleed screw clean off. And a replacement only comes with a complete clutch slave!

[Ginger_Extract]

Bumping this up with a few questions:
When you open the bleeder valves, how much fluid is coming out? Even at 18psi, fluid would barely dribble out of the bleeders, especially on the rears.

Also, how much PSI is everyone using? 10psi did nothing, 15psi barely got a dribble of fluid out, 18psi is what I ended up at, and even then the fluid did not flow out of the bleeder, it just sort of dribbled for a second or two.

[germ]

Question: Now that there is no more contrasting color fluid, how do you know when to stop bleeding?

[Dackelone]

Originally Posted by germ

Question: Now that there is no more contrasting color fluid, how do you know when to stop bleeding?

Even when using the same brake fluid brand/type... the new fluid will always be brighter and clearer in color than the old (dark) fluid. I normally remove/flush 200 to 300ml of fluid at each corner. I usually do all four corners twice - in total.

[Converted1]

Just a thanks to everyone that has posted here. I've done tons of brake fluid swaps with and without motives, but it's always nice to read a day on a new car.

I will add that you need 15psi on the bleeder to get any significant flow and 1L of fluid is just enough if you are watching the color change carefully. 2L if you really want to go overboard on each corner. Shame you can't buy superblue anymore!