Brake fail HELP

lowkey.e90 · 12-08-2018, 02:48 PM

I have a 328i e90 with braking issues. Okay as I was getting off the freeway I was braking pretty hard then I turned off the dsc to "drift" a little since it was raining. Right after that my brake pedal stiffened up, so I have to apply tons of pressure to get the vehicle to stop. No lights are on as I have read on some threads that a faulty abs typically turns on brake, abs, and dsc lights. Not sure it may be the abs pump and not the abs 'computer'? Just changed the brake pads and had cleaned the calipers before the incident. I did the "booster test" which was pumping the brake pedal while the car is off, then while still pressing the brake pedal it should sink once i turned on car. the pedal is stiff at all times I'm going to bleed the brake line to see if that does it. Any info would be great, thanks in advance!

Efthreeoh · 12-08-2018, 02:50 PM

Sounds like there is no vacuum in the brake booster.

lowkey.e90 · 12-08-2018, 02:55 PM

i unpluged the hose going to the brake booster and there is very minimal suction. does that mean the only culprit left is the brake booster?

Efthreeoh · 12-08-2018, 03:01 PM

I don't know what engine you have. The N52 uses a vacuum pump to create vacuum because the valvetronic system doesn't create manifold vacuum. I'd hook up a mechanics vacuum to the booster and see if the pedal feels normal.

lowkey.e90 · 12-08-2018, 03:14 PM

Quote:

Originally Posted by Efthreeoh

I don't know what engine you have. The N52 uses a vacuum pump to create vacuum because the valvetronic system doesn't create manifold vacuum. I'd hook up a mechanics vacuum to the booster and see if the pedal feels normal.

It's an N51. Thanks again for your input

krhodes1 · 12-08-2018, 03:43 PM

Quote:

Originally Posted by lowkey.e90

It's an N51. Thanks again for your input

No difference for this purpose.

Efthreeoh · 12-08-2018, 06:09 PM

Quote:

Originally Posted by lowkey.e90

It's an N51. Thanks again for your input

The N51 has a vacuum pump.

lowkey.e90 · 06-04-2019, 12:44 AM

Just thought I'd update, it was definitely the vacuum pump for the brake booster. It had failed which is very rare.

12-08-2018, 02:48 PM	#1
lowkey.e90 New Member 3 Rep 5 Posts Drives: 2007 e90 Join Date: Dec 2018 Location: Pasadena iTrader: (0)	Brake fail HELP I have a 328i e90 with braking issues. Okay as I was getting off the freeway I was braking pretty hard then I turned off the dsc to "drift" a little since it was raining. Right after that my brake pedal stiffened up, so I have to apply tons of pressure to get the vehicle to stop. No lights are on as I have read on some threads that a faulty abs typically turns on brake, abs, and dsc lights. Not sure it may be the abs pump and not the abs 'computer'? Just changed the brake pads and had cleaned the calipers before the incident. I did the "booster test" which was pumping the brake pedal while the car is off, then while still pressing the brake pedal it should sink once i turned on car. the pedal is stiff at all times I'm going to bleed the brake line to see if that does it. Any info would be great, thanks in advance!
	Appreciate 0 Tweet Quote

12-08-2018, 02:50 PM	#2
Efthreeoh General 17306 Rep 18,733 Posts Drives: The E90 + Z4 Coupe & Z3 R'ster Join Date: May 2012 Location: Virginia iTrader: (0)	Sounds like there is no vacuum in the brake booster. __________________ A manual transmission can be set to "comfort", "sport", and "track" modes simply by the technique and speed at which you shift it; it doesn't need "modes", modes are for manumatics that try to behave like a real 3-pedal manual transmission. If you can money-shift it, it's a manual transmission. "Yeah, but NO ONE puts an automatic trans shift knob on a manual transmission."
	Appreciate 0 Quote

12-08-2018, 02:55 PM	#3
lowkey.e90 New Member 3 Rep 5 Posts Drives: 2007 e90 Join Date: Dec 2018 Location: Pasadena iTrader: (0)	i unpluged the hose going to the brake booster and there is very minimal suction. does that mean the only culprit left is the brake booster?
	Appreciate 0 Quote

12-08-2018, 03:01 PM	#4
Efthreeoh General 17306 Rep 18,733 Posts Drives: The E90 + Z4 Coupe & Z3 R'ster Join Date: May 2012 Location: Virginia iTrader: (0)	I don't know what engine you have. The N52 uses a vacuum pump to create vacuum because the valvetronic system doesn't create manifold vacuum. I'd hook up a mechanics vacuum to the booster and see if the pedal feels normal. __________________ A manual transmission can be set to "comfort", "sport", and "track" modes simply by the technique and speed at which you shift it; it doesn't need "modes", modes are for manumatics that try to behave like a real 3-pedal manual transmission. If you can money-shift it, it's a manual transmission. "Yeah, but NO ONE puts an automatic trans shift knob on a manual transmission."
	Appreciate 0 Quote

06-04-2019, 12:44 AM	#8
lowkey.e90 New Member 3 Rep 5 Posts Drives: 2007 e90 Join Date: Dec 2018 Location: Pasadena iTrader: (0)	Just thought I'd update, it was definitely the vacuum pump for the brake booster. It had failed which is very rare.
	Appreciate 2 e90yyc2425.00 Efthreeoh17306.00 Quote