[OmarG99]

Hey everyone, just wanted to ask a quick question, I just sucked out the brake fluid from the reservoir then bled out each brake, then filled up the reservoir again. I keep trying to pump the brake to fill up the lines again but nothing seems to work, it just keeps feeling like I’m pushing a plastic bag/sponge. Any ideas on what’s going on? I keep reading about people talking about the master cylinder but I’m honestly confused and would use any help I can get.

[Bimmer_Engineer]

You were supposed to refill the reservoir before you bled the brakes...

Perhaps you could get a pressure bleeder and follow the directions. Fill the bleeder and the reservoir...then bleed the brakes starting with the furthest wheel from the master cylinder and working closer...bleed until clean fluid and no air comes out...

[Welcome to NBA Jam]

Originally Posted by OmarG99

Hey everyone, just wanted to ask a quick question, I just sucked out the brake fluid from the reservoir then bled out each brake, then filled up the reservoir again.

You supposed to suck out the old fluid, add in the new fluid, then bleed the brakes while continuing to refill the reservoir when it gets low.

You've probably introduced a lot of air into your system. Hopefully you didn't introduce a bunch of air into your master cylinder. It is not designed to run dry. If you try re-bleeding and you can't get a firm brake pedal, you'll need to remove the master cylinder and bench bleed it to ensure that all of the air is out of your master cylinder.

[OmarG99]

Originally Posted by Welcome to NBA Jam

You supposed to suck out the old fluid, add in the new fluid, then bleed the brakes while continuing to refill the reservoir when it gets low.

You've probably introduced a lot of air into your system. Hopefully you didn't introduce a bunch of air into your master cylinder. It is not designed to run dry. If you try re-bleeding and you can't get a firm brake pedal, you'll need to remove the master cylinder and bench bleed it to ensure that all of the air is out of your master cylinder.

Do I need to do this rn, or can I leave it overnight for now?

[OmarG99]

Originally Posted by Bimmer_Engineer

You were supposed to refill the reservoir before you bled the brakes...

Perhaps you could get a pressure bleeder and follow the directions. Fill the bleeder and the reservoir...then bleed the brakes starting with the furthest wheel from the master cylinder and working closer...bleed until clean fluid and no air comes out...

Am I able to just do the same process without the bleeder again? (The right way this time)

[Welcome to NBA Jam]

Originally Posted by OmarG99

Do I need to do this rn, or can I leave it overnight for now?

You can do it tomorrow. Try re-bleeding it first. You might need to do a lot of pumps. Keep going at it until you get a firm brake pedal. Grab a big container of brake fluid though. You could be doing a lot of flushing.

[OmarG99]

Originally Posted by Welcome to NBA Jam

You can do it tomorrow. Try re-bleeding it first. You might need to do a lot of pumps. Keep going at it until you get a firm brake pedal. Grab a big container of brake fluid though. You could be doing a lot of flushing.

Ya that’s what I’m worried about haha, I saved a lot of the old brake fluid but it’s all black, so I’ll just go buy cheaper DOT 4 brake fluid and complete the process with that, I don’t wanna waste my ATE brake fluid. Thanks for the help 👍🏼

[Efthreeoh]

I believe to fix things, you need to first understand how they work.

Based on your description of how you tried to bleed the brakes, it's obvious you don't understand how they work. So first, a little physics. The system is based on Pascal's principal where force can be transferred through fluid. Force can be transferred through the fluid because fluids basically don't compress very well, so pressure is easily created and the pressure of the fluid transfers the force. The brake system uses five (5) hydraulic pistons to transfer the force using the fluid. One piston sits in what is called the "master" cylinder and the other four (4) pistons sit in what are called are "slave" cylinders, one (1) at each brake caliper at each wheel. When you push on the brake pedal, which is connected to the piston in the master cylinder, it compresses the brake fluid and pushes it through the small brake pipes and hoses to compress the fluid stored in each of the slave cylinders and pushes the piston in each brake caliper. The brake caliper piston then pushes one of the brake pads against the brake disk, which clamps both brake pads on the disk. This is action of transferring the force from your foot from the master cylinder to the calipers.

Now to your problem, when you pulled the fluid out of the mater cylinder reservoir and did not preplace it, you just pumped air into the system to push the old fluid out of each caliper. Filling the reservoir with new brake fluid BEFORE you start bleeding the old fluid out at each caliper then uses the new fluid (rather than air as you did) to push out the old fluid of each caliper. Pulling the old fluid out of the master cylinder reservoir and then filling the reservoir with new fluid as the first step just speeds up the process by replacing most of the old fluid before it get cycled through the system and out the calipers. Your brakes are now spongey because you have air in the brake lines and calipers. Air is highly compressible (as compared to fluid), so pushing on the brake pedal is just compressing the air in the brake lines.

So as others have said, you need to start over and bleed the system the proper way using the correct technique. While a pressure bleeder would help greatly here, you can use the pump method (if you have a partner to pump the brake pedal) to bleed the brakes - if you use a buddy to pump the brake pedal try to not bottom the pedal out because it can, if bottomed repeatedly, possibly damage the master cylinder. Now, the only unusual issue you may have trying to restore the function of your brake system is you probably pumped air into the ABS valve body, which is not a good situation. The ABS valve body is a device that prevents the brakes from locking the wheels (tires) and the car skidding by rapidly varying the brake line pressure to each wheel from your panicked foot slammed down on the brake pedal. Bleeding the air out of the ABS valve body is not easy and usually requires cycling the ABS function (rapidly opening and closing the valves in the ABS valve body), which is accomplished by using a computer to communicate with the valve body to cycle it. To cycle the ABS valve body, you need a device that runs BMW diagnostic software. You can learn about such diagnostic software in the coding subforum.

About brake fluid... (I know I'll get flamed here). Brake fluid is a chemical produced to a engineering specification. All BMWs use "DOT 4" brake fluid; "DOT" meaning (US) Department of Transportation. So any brake fluid that is rated as meeting DOT 4, regardless of its price, is completely adequate for your car. ATE is just a brand of brake fluid. NAPA DOT 4 brake fluid will work just as good as ATE, but just isn't as cool to use because it doesn't have a designer name.

The last bit of advice is consult the BMW Newtis.info website to review BMW repair procedures. Sorry for the long post, but hopefully it helps you get the brake system operating correctly.

[Efthreeoh]

Originally Posted by OmarG99

Am I able to just do the same process without the bleeder again? (The right way this time)

OP, are you using a catch bottle on the caliper side?

[nsjames]

technically since you've introduced air into the master, you should pull it and bench bleed it.
would strongly urge an amazon purchase of the motive power bleeder if you want to make this process a whole lot easier on yourself.

https://www.amazon.com/Motive-Produc...f=sr_1_1_sspa?


trust me. it's $50 well spent.
you won't have to worry about bench bleeding, bleeding the abs module or any of that.

[Bimmer_Engineer]

Originally Posted by nsjames

technically since you've introduced air into the master, you should pull it and bench bleed it.
would strongly urge an amazon purchase of the motive power bleeder if you want to make this process a whole lot easier on yourself.

https://www.amazon.com/Motive-Produc...f=sr_1_1_sspa?


trust me. it's $50 well spent.
you won't have to worry about bench bleeding, bleeding the abs module or any of that.

+1 on the pressure bleeder...

[gbalthrop]

Originally Posted by Efthreeoh

[1] I believe to fix things, you need to first understand how they work... [AMEN BRO' ]

[2] Now, the only unusual issue you may have trying to restore the function of your brake system is you probably pumped air into the ABS valve body, which is not a good situation. The ABS valve body is a device that prevents the brakes from locking the wheels (tires) and the car skidding by rapidly varying the brake line pressure to each wheel from your panicked foot slammed down on the brake pedal. Bleeding the air out of the ABS valve body is not easy and usually requires cycling the ABS function (rapidly opening and closing the valves in the ABS valve body), which is accomplished by using a computer to communicate with the valve body to cycle it. To cycle the ABS valve body, you need a device that runs BMW diagnostic software. You can learn about such diagnostic software in the coding subforum.

[3] About brake fluid... (I know I'll get flamed here). Brake fluid is a chemical produced to a engineering specification. All BMWs use "DOT 4" brake fluid; "DOT" meaning (US) Department of Transportation. So any brake fluid that is rated as meeting DOT 4, regardless of its price, is completely adequate for your car. ATE is just a brand of brake fluid. NAPA DOT 4 brake fluid will work just as good as ATE, but just isn't as cool to use because it doesn't have a designer name...

BLEEDING ABS VALVE BLOCK:
OmarG, I hope I'm wrong, but I'm afraid that NO amount of bleeding by normal methods, including pressure bleeder, bench bleeding Master Cylinder, or any of that is going to cure your spongy pedal issue. As "F30" has stated, if during the bleeding process one allows the fluid level in the master cylinder to drop below the fluid intake ports, AIR is drawn into the Master Cylinder, which will THEN be introduced into the ABS Valve Block. NOW you have an issue -- but fortunately there's an "App" for that. INPA (or ISTA?) should have an F6 Activation Function (F6 | F1 Control Valve Bleeding Routines (Ventilansteuerung/ Entlueftungsroutinen) that can be used to get the air out of the ABS Valve Body.

ANYONE actually used such an Actuation Program (INPA or ISTA) to bleed the ABS Valve Block, who can provide details? I've seen the function in INPA but have never used it, or even pressed F6, F1 (on my 328xi with "DXC8 Plus" module -- other DSC variants may differ) to see what "Test Conditions" or other warnings/ instructions appear (IF if ain't broke, don't fix it ;-)

BRAKE FLUID:
Having the respect that I do for the "Advertising Profession" (read "being the cynic that I am" ;-) I have to wonder what the difference is between ANY (cheapest you can find) "DOT 4" rated brake fluid and "BMW 'Low Viscosity'" DOT 4 brake fluid. Unless you are using the car on the track, where you are either "on the gas" or "on the brake", is there REALLY anything to be gained by using anything other than "the cheapest DOT 4 fluid you can find"??

So let's start a new "oil thread" and see what FACTS, opinions, conspiracy theories, or whatever "thoughts" forum members may have about what brake fluid to use & WHY. Cheapest "BMW-approved" fluid I've found, Ate no-longer-blue (but the can is ;-) $12.32/L, or $56.71/5L:
https://www.getbmwparts.com/p-ate-or...fluid-1l-sblue
https://www.amazon.com/BMW-Brake-Flu...s%2C138&sr=8-7

For the heretics in the group, here's the "Loss Leader" weighing in at $5.74/Qt (32 oz.), also in BLUE Trunks.
https://www.walmart.com/ip/Super-Tec...luid/290538192

George

[OmarG99]

Originally Posted by Efthreeoh

OP, are you using a catch bottle on the caliper side?

Yes

[OmarG99]

Originally Posted by nsjames

technically since you've introduced air into the master, you should pull it and bench bleed it.
would strongly urge an amazon purchase of the motive power bleeder if you want to make this process a whole lot easier on yourself.

https://www.amazon.com/Motive-Produc...f=sr_1_1_sspa?


trust me. it's $50 well spent.
you won't have to worry about bench bleeding, bleeding the abs module or any of that.

Do I HAVE to get it? And if I’m being honest I’m not sure what you mean by bench bleeding

[OmarG99]

Originally Posted by Efthreeoh

I believe to fix things, you need to first understand how they work.

Based on your description of how you tried to bleed the brakes, it's obvious you don't understand how they work. So first, a little physics. The system is based on Pascal's principal where force can be transferred through fluid. Force can be transferred through the fluid because fluids basically don't compress very well, so pressure is easily created and the pressure of the fluid transfers the force. The brake system uses five (5) hydraulic pistons to transfer the force using the fluid. One piston sits in what is called the "master" cylinder and the other four (4) pistons sit in what are called are "slave" cylinders, one (1) at each brake caliper at each wheel. When you push on the brake pedal, which is connected to the piston in the master cylinder, it compresses the brake fluid and pushes it through the small brake pipes and hoses to compress the fluid stored in each of the slave cylinders and pushes the piston in each brake caliper. The brake caliper piston then pushes one of the brake pads against the brake disk, which clamps both brake pads on the disk. This is action of transferring the force from your foot from the master cylinder to the calipers.

Now to your problem, when you pulled the fluid out of the mater cylinder reservoir and did not preplace it, you just pumped air into the system to push the old fluid out of each caliper. Filling the reservoir with new brake fluid BEFORE you start bleeding the old fluid out at each caliper then uses the new fluid (rather than air as you did) to push out the old fluid of each caliper. Pulling the old fluid out of the master cylinder reservoir and then filling the reservoir with new fluid as the first step just speeds up the process by replacing most of the old fluid before it get cycled through the system and out the calipers. Your brakes are now spongey because you have air in the brake lines and calipers. Air is highly compressible (as compared to fluid), so pushing on the brake pedal is just compressing the air in the brake lines.

So as others have said, you need to start over and bleed the system the proper way using the correct technique. While a pressure bleeder would help greatly here, you can use the pump method (if you have a partner to pump the brake pedal) to bleed the brakes - if you use a buddy to pump the brake pedal try to not bottom the pedal out because it can, if bottomed repeatedly, possibly damage the master cylinder. Now, the only unusual issue you may have trying to restore the function of your brake system is you probably pumped air into the ABS valve body, which is not a good situation. The ABS valve body is a device that prevents the brakes from locking the wheels (tires) and the car skidding by rapidly varying the brake line pressure to each wheel from your panicked foot slammed down on the brake pedal. Bleeding the air out of the ABS valve body is not easy and usually requires cycling the ABS function (rapidly opening and closing the valves in the ABS valve body), which is accomplished by using a computer to communicate with the valve body to cycle it. To cycle the ABS valve body, you need a device that runs BMW diagnostic software. You can learn about such diagnostic software in the coding subforum.

About brake fluid... (I know I'll get flamed here). Brake fluid is a chemical produced to a engineering specification. All BMWs use "DOT 4" brake fluid; "DOT" meaning (US) Department of Transportation. So any brake fluid that is rated as meeting DOT 4, regardless of its price, is completely adequate for your car. ATE is just a brand of brake fluid. NAPA DOT 4 brake fluid will work just as good as ATE, but just isn't as cool to use because it doesn't have a designer name.

The last bit of advice is consult the BMW Newtis.info website to review BMW repair procedures. Sorry for the long post, but hopefully it helps you get the brake system operating correctly.

Wow haha thanks for the help and yeah I wish I knew before I started I just rushed into it. So do I really NEED a pressure bleeder? Or just keep one caliper bleeder open and keep pumping the pedal (as I add fluid to the reservoir)? And continue with the other 3 ofc

[e90yyc]

Originally Posted by OmarG99

Ya that’s what I’m worried about haha, I saved a lot of the old brake fluid but it’s all black, so I’ll just go buy cheaper DOT 4 brake fluid and complete the process with that, I don’t wanna waste my ATE brake fluid. Thanks for the help 👍🏼

Your old fluid was black!?

Another +1 on the pressure bleeder. I use a different model than most (Schwaben), but it functions the same.

Bench bleeding entails removal of the master cylinder and bleeding it on your workbench.

[OmarG99]

Originally Posted by e90yyc

Your old fluid was black!?

Another +1 on the pressure bleeder. I use a different model than most (Schwaben), but it functions the same.

Bench bleeding entails removal of the master cylinder and bleeding it on your workbench.

Yup it looked awful, and I guess I’ll have to look for instructions on how to use the pressure bleeder, do I really need it tho? Because I’m trying to save the most amount of money here 😂

[Efthreeoh]

Originally Posted by OmarG99

Wow haha thanks for the help and yeah I wish I knew before I started I just rushed into it. So do I really NEED a pressure bleeder? Or just keep one caliper bleeder open and keep pumping the pedal (as I add fluid to the reservoir)? And continue with the other 3 ofc

I'm really guessing here, but if I were in your situation I'd get a pressure bleeder (you can use it in 2 years to flush brakes again - the flush schedule is every 24 months from the build date of the car). With a pressure bleeder correctly setup, which means loaded at least half-full with fresh brake fluid and pressurized to 18 PSI, I'd connect a catch bottle to the front left brake caliper and open the bleed screw. Then I'd have an assistant get in the car and slowly press the brake pedal to see if the open hydraulic circuit will draw brake fluid into the master cylinder and out the brake caliper. I suggest the front left brake because it has the shortest hydraulic circuit, so there is less air to purge. You need an assistant here to operate the brake pedal while you observe the brake fluid ejecting from the caliper(s). I'd let you borrow my wife, as she is an expert, master-level brake pedal operation technician with 30 years experience, but we're on the East Coast, so you'll need to find someone local...

If you can get bubble-free fluid out of the left front brake caliper, then close the bleeder valve. Check the level of the fluid in the pressure bleeder (it still should be close to half-full) and check the pressure and pump it back up to 20 PSI.

Then start at the right rear brake as normally you would, and start bleeding the brakes correctly. Finally, bleed the front left brake again. If you are getting bubble-free fluid ejecting from each caliper, you may be home free, or at least have the car drivable. Drivable to an independent BMW shop and pay them to properly bleed the ABS valve body.

[ctuna]

To really do it properly you need Ista D or Inpa to run the anti lock
brake bleed procedure. Also if you have a manual it shares the fluid
in a split reservoir so you need to bleed the clutch at the same time.
I don't think brakes and tires is a thing to be looking for the cheapest
option on.

[Efthreeoh]

Originally Posted by e90yyc

Your old fluid was black!?

Another +1 on the pressure bleeder. I use a different model than most (Schwaben), but it functions the same.

Bench bleeding entails removal of the master cylinder and bleeding it on your workbench.

Maybe there was some old ATE-blue in the system... or its 8 years old

[Welcome to NBA Jam]

Originally Posted by Efthreeoh

Maybe there was some old ATE-blue in the system... or its 8 years old

RIP easiest brake flushes ever. It's for the best, I guess. Our government feels that people could confuse it for windshield washer fluid. That sounds like a good reason, right?

[OmarG99]

Originally Posted by Efthreeoh

Maybe there was some old ATE-blue in the system... or its 8 years old

It was weird, when I flushed the rear calipers the fluid looked new except the front which was black, I’ve owned the car for about 2 years now so there’s that. 2011 335i previously owned.