|
|
01-07-2018, 11:57 PM | #1 |
Private
8
Rep 57
Posts
Drives: 2012 Z4 35is
Join Date: Aug 2015
Location: Auburn
|
how to do ABS bleeding
hi all
does anyone know how to e89 (2012 35is) abs bleeding? normally my break works but when I make quick & heavy break, ABS comes to fast. i already did break bleeding enough, I think there must be air in the abs pressure pipe when i disconnected break hose and caliper for 3 days ( by the way,,, is it possible?) |
01-08-2018, 06:19 AM | #2 |
New Member
2
Rep 17
Posts |
If you had air in the ABS pump you would have a spongy pedal
I doubt it would affect how the ABS pump kicks in, as that is determined by the ABS sensors detecting that a wheel has slowed down compared to the others. but to pulse the ABS pump for bleeding you will need OBD11 connected software. |
Appreciate
0
|
01-08-2018, 02:52 PM | #3 |
Private First Class
32
Rep 193
Posts |
Brake bleeding doesn't effect the ABS module as the valves are closed while the engine is off. How did you bleed the brakes? Only safe way is with pressurized brake bleeder. Any other method opens possibility air will be left in system. Do you have a hard brake pedal with engine off after pumping pedal several times? If you do odds are you don't have air in lines. If you still have ABS problems start looking at wheel sensors assemblies.
|
Appreciate
0
|
01-09-2018, 12:42 PM | #4 |
Captain
164
Rep 906
Posts
Drives: 2008 535xi / 2011 Z4 35Is
Join Date: Jan 2011
Location: Indiana
|
I am not sure on what judgement you use to say it comes on too fast.
Perhaps you have bad tires? Perhaps the road isn't as dry as you think? I would want more info before I contributed to troubleshooting the ABS system based on this information. |
Appreciate
0
|
01-09-2018, 01:59 PM | #5 |
Colonel
245
Rep 2,387
Posts |
If only this were true. If air gets in the system it can get trapped in the module. This can happen with routine bleeding, although unlikely unless you really don't know what you're doing. More likely it's when you're replacing a master cylinder or booster, both of which are upstream of the module. In which case you either need software to activate the ABS pump while bleeding or (I have heard) you can take the car out and panic stop, which activates the pump. Do that a few times and bleed again.
__________________
2016 340i XDrive, EBII/black, 6 MT, M Sport, Track Handling, Cold Weather, Tech, Lighting, Driver Assistance Plus.
2012 Z4 35i, ED 2/24/2012, Melbourne Red Metallic, Black Leather, Carbon Trim, 6MT, M Sport, CW, PP, PS, NAV, CA. |
Appreciate
0
|
01-10-2018, 02:34 PM | #6 | |
Private First Class
32
Rep 193
Posts |
Quote:
|
|
Appreciate
0
|
01-11-2018, 02:02 PM | #7 | |
Colonel
245
Rep 2,387
Posts |
Quote:
__________________
2016 340i XDrive, EBII/black, 6 MT, M Sport, Track Handling, Cold Weather, Tech, Lighting, Driver Assistance Plus.
2012 Z4 35i, ED 2/24/2012, Melbourne Red Metallic, Black Leather, Carbon Trim, 6MT, M Sport, CW, PP, PS, NAV, CA. |
|
Appreciate
0
|
01-11-2018, 04:56 PM | #8 |
Private First Class
32
Rep 193
Posts |
Brake lines go from MC to calipers. ABS valves are closed so there is no flow through ABS unit. When ABS actuates valves cycle open at a set frequency on brake line where speed sensor indicates wheel lock up, ergo the pulsing pedal. The cycling open valve relieves brake pressure on locked wheel until it starts to move again.
|
Appreciate
0
|
01-11-2018, 05:11 PM | #9 | |
Captain
164
Rep 906
Posts
Drives: 2008 535xi / 2011 Z4 35Is
Join Date: Jan 2011
Location: Indiana
|
Quote:
So the ABS releases the brakes, it does not apply them. |
|
Appreciate
0
|
01-16-2018, 10:36 PM | #10 |
Private
8
Rep 57
Posts
Drives: 2012 Z4 35is
Join Date: Aug 2015
Location: Auburn
|
here is more information
i painted and replaced break pad, for better paint result, i disconnected caliper from break oil hose for 3days, ( i did hang the hose up at the highest position i could i got masking for oil leaking on hose) then i got sponge break pedal so, i did bleeding a lot ( total 1 liter, each caliper) then now 1. break works at normal operation but still ABS comes too fast at quick&heavy pedal 2. i can feel the difference between before & after 3. no matter how dry or wet road is... 4. tire condition is good (thread 6-7/32) 5. i pushed break pedal many time when engine is off --> pedal goes down at pretty much same distance with same pressure --> pedal does not get harder 6. turned engine on, pushed pedal at zero speed --> does not get harder what is wrong with my break? do i still need more bleeding? |
Appreciate
0
|
01-16-2018, 11:24 PM | #11 |
Captain
164
Rep 906
Posts
Drives: 2008 535xi / 2011 Z4 35Is
Join Date: Jan 2011
Location: Indiana
|
It does seem like your bleeding technique could be off.
1 liter per caliper is a LOT but if you are doing it incorrectly then .... Is this your first time bleeding brakes or is this something you actually have done successfully before? |
Appreciate
0
|
01-18-2018, 08:46 AM | #12 |
Private First Class
32
Rep 193
Posts |
If you push pedal down several times with engine off pedal should become harder as vacuum boost is lost. If it does not get harder you still have air in lines.
I had similar problem when installing 330 front brakes and rotors on my Z4. Look at front brake lines. The lines go up and over suspension. at the top of the loop air can get trapped. When I pressure bled the brakes I had to keep tapping the brake line at the top of the loop to free trapped bubbles. It took awhile but it worked. BMW design problem. Another thought. Have you checked the slide pins on your calipers to see if they are properly lubricated or are worn. A stuck pin could cause a caliper to lock up causing the ABS to actuate. Last edited by Vetracr; 01-18-2018 at 08:53 AM.. |
Appreciate
0
|
Post Reply |
Bookmarks |
|
|