Brake Fluid above Max

Pittsburger · 08-18-2012, 03:26 PM

So, I did my first brake job on E90 330xi 2006 today.

On the last two wheels I decided to open the hood and check the brake level. It was close to max. I shrugged, pumped the brakes, and did the last two wheels.

I rechecked the level:
Luckily it hasn't overfilled, but it is now ABOVE the max level.
Also, when I pumped the brakes, I noticed there was not as much give compared to after replacing the front brakes or the opposite rear brakes.

I have no experience bleeding the brakes and was thinking of getting a clean/new syringe and pulling it out of the reservoir.

My question is... when you do this, isn't it bad for the fluid since you're exposing it to the moisture in the air (which will eventually be absorbed in the brake fluid?)

Secondary question, is it easier/better to bleed a little of the brake fluid out near one of the wheels?

Thanks.

Brad from the OC · 08-18-2012, 03:45 PM

I don't know how long you have owned your car, but BMW recommends that the brake fluid should be flushed out and replaced every 2 years. Check your CBS screen if you're a new owner and don't know when the fluid is due for a change. If it is due soon or overdue, having the brake fluid flushed will remove any air trapped in the system and replace any water contaminated brake fluid.
Sucking out any excess brake fluid from the reservoir should not pose a problem unless you accidently used a contaminated syringe and introduced dirt or water into your system.
I wouldn't advise to remove excess fluid using the bleeder on any of the wheels. If you don't have experience bleeding brakes and don't know the bleeding procedure, you will probably introduce air into your system. If you are able to replace the brake pads by yourself, you should be able to learn how to bleed the brakes. Bleeding brakes are a lot easier and quicker than replacing brake pads and sensors.
If your brake pedal feels soft and not as firm as before the brake pad change, you might just want to drive your car for a few weeks and let the new pads bed into the rotor.

Pittsburger · 08-18-2012, 08:52 PM

Thanks for the quick response. I searched the web and many advise not to have the fluid over the max line citing that fluid may expand with increased temperatures and over flow. So I went to walgreens and picked up an oral syringe and used this to pull the excess. It was clean, but I used an empty oil bottle and didn't wipe the lip. So... Some oil residue may have been introduced to the fluid. (I didn't see any but the syringe did touch the lip at least once). Anyhow, yes car gets flushed every 2years be dealer. Maybe this time I will learn to do it.

Brakes are firm. DYI success thanks to this site and all it's members!

08-18-2012, 03:26 PM	#1
Pittsburger Private First Class 7 Rep 132 Posts Drives: 2010 328xi, 2006 330xi, 2011x3 Join Date: Aug 2011 Location: Des Moines, IA iTrader: (0)	Brake Fluid above Max So, I did my first brake job on E90 330xi 2006 today. On the last two wheels I decided to open the hood and check the brake level. It was close to max. I shrugged, pumped the brakes, and did the last two wheels. I rechecked the level: Luckily it hasn't overfilled, but it is now ABOVE the max level. Also, when I pumped the brakes, I noticed there was not as much give compared to after replacing the front brakes or the opposite rear brakes. I have no experience bleeding the brakes and was thinking of getting a clean/new syringe and pulling it out of the reservoir. My question is... when you do this, isn't it bad for the fluid since you're exposing it to the moisture in the air (which will eventually be absorbed in the brake fluid?) Secondary question, is it easier/better to bleed a little of the brake fluid out near one of the wheels? Thanks.
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08-18-2012, 03:45 PM	#2
Brad from the OC Private First Class 15 Rep 153 Posts Drives: 325Ia Alpine White Join Date: May 2006 Location: Southern California iTrader: (0)	I don't know how long you have owned your car, but BMW recommends that the brake fluid should be flushed out and replaced every 2 years. Check your CBS screen if you're a new owner and don't know when the fluid is due for a change. If it is due soon or overdue, having the brake fluid flushed will remove any air trapped in the system and replace any water contaminated brake fluid. Sucking out any excess brake fluid from the reservoir should not pose a problem unless you accidently used a contaminated syringe and introduced dirt or water into your system. I wouldn't advise to remove excess fluid using the bleeder on any of the wheels. If you don't have experience bleeding brakes and don't know the bleeding procedure, you will probably introduce air into your system. If you are able to replace the brake pads by yourself, you should be able to learn how to bleed the brakes. Bleeding brakes are a lot easier and quicker than replacing brake pads and sensors. If your brake pedal feels soft and not as firm as before the brake pad change, you might just want to drive your car for a few weeks and let the new pads bed into the rotor.
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08-18-2012, 08:52 PM	#3
Pittsburger Private First Class 7 Rep 132 Posts Drives: 2010 328xi, 2006 330xi, 2011x3 Join Date: Aug 2011 Location: Des Moines, IA iTrader: (0)	Thanks for the quick response. I searched the web and many advise not to have the fluid over the max line citing that fluid may expand with increased temperatures and over flow. So I went to walgreens and picked up an oral syringe and used this to pull the excess. It was clean, but I used an empty oil bottle and didn't wipe the lip. So... Some oil residue may have been introduced to the fluid. (I didn't see any but the syringe did touch the lip at least once). Anyhow, yes car gets flushed every 2years be dealer. Maybe this time I will learn to do it. Brakes are firm. DYI success thanks to this site and all it's members!
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