Brake fluid

sl13 · 03-02-2020, 02:06 PM

Hi all,

I'm going to do my brakes on my jeep that takes a dot3 or dot4.

The wife's 335d is dot 4 (although, manual doesn't state this at all - useless!).

Is there any other spec I should be aware of? I plan to use this Comma BF41L 1L DOT 4 Brake and Clutch Fluid. It's low viscosity and would do both cars.

Any thoughts or comments would be welcome.

Thanks v much

Sl13

cfm56d7b · 03-02-2020, 03:55 PM

I usually use whatever brake fluid BMW service department uses. It literally just works.

OregonDude · 03-02-2020, 06:36 PM

I believe most newer BMW vehicles use DOT4 low viscosity fluid.
This is the one I use when doing the system flush:

sl13 · 03-03-2020, 01:58 AM

Thanks guys,

I've noted your recommendations but have gone with some comma dot 4 esp (!). It will do both my cars and will upgrade the performance of the fluid in the jeep. I'll be doing this swap regularly now so will see how I go.

Any tips on bleeding the brakes? I've got a bleeder pressure pump (for the MC), plan is, get some of the old crap out with a baster, hook up pump, add fluid to pump, seal, pressure to 10-12psi, go to furthest wheel, remove it, attach catch can, tube on nipple, open valve. Stop periodically to check fluid in then pressure tank. I'm a little unsure how the pressure tank doesn't let air in but I am sure there is a simple physics law that will tell me...

03-02-2020, 02:06 PM	#1
sl13 Private First Class 80 Rep 121 Posts Drives: 335d xdrive Msport Join Date: Nov 2019 Location: Herefordshire iTrader: (0)	Brake fluid Hi all, I'm going to do my brakes on my jeep that takes a dot3 or dot4. The wife's 335d is dot 4 (although, manual doesn't state this at all - useless!). Is there any other spec I should be aware of? I plan to use this Comma BF41L 1L DOT 4 Brake and Clutch Fluid. It's low viscosity and would do both cars. Any thoughts or comments would be welcome. Thanks v much Sl13
	Appreciate 0 Tweet Quote

03-02-2020, 03:55 PM	#2
cfm56d7b Lieutenant General 5886 Rep 10,256 Posts Drives: 2017 440i Gran Coupe & 2015 X5 Join Date: Nov 2012 Location: Orange County, CA iTrader: (2)	I usually use whatever brake fluid BMW service department uses. It literally just works.
	Appreciate 0 Quote

03-02-2020, 06:36 PM	#3
OregonDude New Member 12 Rep 26 Posts Drives: 2014 F33 435i Convertible Join Date: Sep 2014 Location: Oregon iTrader: (0)	I believe most newer BMW vehicles use DOT4 low viscosity fluid. This is the one I use when doing the system flush: __________________ Current stable of BMW vehicles: 2019 G01 X3 m40i 2014 F33 435i convertible
	Appreciate 0 Quote

03-03-2020, 01:58 AM	#4
sl13 Private First Class 80 Rep 121 Posts Drives: 335d xdrive Msport Join Date: Nov 2019 Location: Herefordshire iTrader: (0)	Thanks guys, I've noted your recommendations but have gone with some comma dot 4 esp (!). It will do both my cars and will upgrade the performance of the fluid in the jeep. I'll be doing this swap regularly now so will see how I go. Any tips on bleeding the brakes? I've got a bleeder pressure pump (for the MC), plan is, get some of the old crap out with a baster, hook up pump, add fluid to pump, seal, pressure to 10-12psi, go to furthest wheel, remove it, attach catch can, tube on nipple, open valve. Stop periodically to check fluid in then pressure tank. I'm a little unsure how the pressure tank doesn't let air in but I am sure there is a simple physics law that will tell me...
	Appreciate 0 Quote