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535i Andrew

F10 535i Brake Fluid change (Front caliper only) DIY

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When changing my front discs and pads I took the opportunity to bled out/replace 500ml of brake fluid in each front caliper.  When I changed the discs and pads I retracted the caliper piston and expelled the displaced fluid out via the bleed screw, so to make sure I didn't get air in the system doing this, I bled out the fluid.  It had been previously changed by BMW in Dec 17, which was confirmed by the fact that the fluid that came out was relatively light in colour and the bleed screws opened without issue.

 

This is just for the front calipers, a partial fluid change.

 

Tools needed

17mm socket for wheel bolts

Breaker bar

Torque wrench (capable of 140Nm)

11mm combination spanner for opening the bleed screws

Brake bleed kit, tube with non return valve

Bottle for catching expanded fluid

Expanding rivet removal (trim) tool.

Trolley jack

Assistant to pump brake pedal (my dad!)

 

Jack up and remove each front wheel in turn.  I turn the steering wheel so that the caliper (at the rear of the hub) is positioned so that it is turned out away from the car just to make access easier.

 

Using the expanding rivet removal tool remove the three expanding rivets in the trim panel above the brake fluid reservoir, this is just in front and to the left of the driver side wiper spindle.

 

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Three rivets removed with trim tool

 

To remove the panel you need to pull up on the black rubber seal around the engine bay to allow the panel to be removed.  

 

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Set aside the cover.

 

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This allows access to the brake fluid reservoir.

 

Clean around the cap and unscrew it and set it aside on something to catch any drips. Get you brake fluid handy

 

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I had set up a brake fluid bleeding kit into a empty 2L Irn Bru bottle which I had marked graduations on the side in 250ml increments.  Using the 11mm combination spanner open the bleed screw.  My dad then pumped the brake pedal to the floor ten times, holding it to the floor on the 10th stroke.  I then tightened up the bleed screw and topped up the brake fluid reservoir.  This was repeated in multiples of 10 pedal strokes until 500ml of brake fluid was in the 2L Irn Bru bottle.

 

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As it is a non return valve there is no need to ensure the tube remains below the fluid level.  I had bought a new brake bleeding kit identical to the one I bought in 2012 to do my E60 front brakes, but it popped open and sprayed me and the wheel arch with brake fluid.  It then fell in the bottle and I used my old one successfully.

 

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Old fluid (and new bleed kit!) having been pumped out and the two 500ml bottles of BMW DOT 4 fluid that I put in.

 

Brake fluid reservoir fluid level double checked and cap put back on, then the panel and I then banged back the black rubber seal.  Replace road wheel and torque wheel bolts to 140Nm.

 

If you are doing this as part of a service after your brake fluid service warning has appeared you then need to reset the service warning.  

 

Follow this post but obviously make sure its the brake fluid service item you are resetting.

 

 

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Nice write up and good guide.  

 

All I will say is you should not really pump the brake pedal to the floor.  It has been known to damage the seals in the master cylinder.   A pressure bleeder can be purchased relatively cheap these days and is a much safer way of doing it.  (plus your able to bleed on your own)

 

 

Edited by Enzo503

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7 hours ago, Enzo503 said:

Nice write up and good guide.  

 

All I will say is you should not really pump the brake pedal to the floor.  It has been known to damage the seals in the master cylinder.   A pressure bleeder can be purchased relatively cheap these days and is a much safer way of doing it.  (plus your able to bleed on your own)

 

 

 

Thanks, I do have a vacuum brake fluid extractor, but I've got a bit of a love hate relationship with my air tools at the moment so didn't use it, plus that would make the need for my dad redundant, and I'm not ready for that yet.

 

Your point is a good one and having done several brake fluid changes on my E60 and now the F10, I guess I've been lucky that I've not flipped a seal.

 

The F10 will need a full brake fluid change at the end of this year so I'll try my vacuum one or look at a pressure system.

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I’ve never used a second person, a non-return valve or a vacuum system when bleeding brakes. Years ago a mechanic pointed out that there’s so much resistance to fluid being sucked back through the bleed nozzle compared with from the reservoir that no precautions against suction are really necessary, just let the pedal return smoothly. Any minor amount of old fluid sucked in is insignificant overall. So I’ve always done it like that, seems to work fine. I agree with @Enzo503 though that you shouldn’t bottom the pedal, and it isn’t necessary anyway, just smooth pressure.

Edited by Boba

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On 13/01/2019 at 11:41, Enzo503 said:

Nice write up and good guide.  

 

All I will say is you should not really pump the brake pedal to the floor.  It has been known to damage the seals in the master cylinder.   A pressure bleeder can be purchased relatively cheap these days and is a much safer way of doing it.  (plus your able to bleed on your own)

 

 

 

Good write up.

I am about to bleed my brakes and have bought a pressure bleeder as it seems pretty straightforward (I hope).

I was wondering if there any need to pump after each wheel has been bled or should I just wait until all 4 have been bled? or does it make any difference?

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I was looking at pressure bleeders today. Some good videos on YouTube. Some use a hand pump to create pressure, others use a tyre as a pressure source. 

 

I would do a wheel in turn and check the pedal has resistance after each wheel. But that's how I work checking things as I go along.

 

Pressure would be better than a vacuum extraction as with vacuum you may suck air in via the threads of the bleed nipple thus making it less effective. As you are sucking fluid and potentially air too.

 

Pressure bleed would force out fluid thru the threads as well as the nipple so it would be better. 

 

As I have a source of compressed air I would want one that used that  albeit regulated down to max 1.5 bar or ~20psi which is much lower than a tyre air pressure.

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Thanks Andrew, that's probably the way I'll proceed. I like to do these things slowly. I think 15psi should be adequate.

My plan was to use a turkey baster to syphon off most of the old fluid in the reservoir, top it off with new fluid, and then use my Pressure bleeder to bleed each wheel in turn, starting at the passenger rear, then drivers rear, then passenger front, and finally driver's front.

To give it a proper bleed, how much fluid do you think I should be discharging? 500mL per wheel?

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8 minutes ago, Johnboy65 said:

Thanks Andrew, that's probably the way I'll proceed. I like to do these things slowly. I think 15psi should be adequate.

My plan was to use a turkey baster to syphon off most of the old fluid in the reservoir, top it off with new fluid, and then use my Pressure bleeder to bleed each wheel in turn, starting at the passenger rear, then drivers rear, then passenger front, and finally driver's front.

To give it a proper bleed, how much fluid do you think I should be discharging? 500mL per wheel?

 

I've used a large medical syringe before to suck out the fluid, i didn't do that this time as the last thing you want to do is put something that may be a bit dirty into the brake fluid reservoir. To be honest putting 500ml thru each caliper will be fine.  Start with the nearside rear (furthest from reservoir) then offside rear, nearside front and then offside front. Work towards the reservoir basically.

 

I've always bought 2 litres of brake fluid so that's 500ml per wheel when doing a full change, partly because my E60 and the F10 have massive calipers which hold a lot of fluid.  The smaller engined stuff has smaller calipers so needs less fluid.

 

I did not notice a change in fluid colour between the stuff I poured in compared to the stuff I pumped out which ties in with it only being in there for a year on my F10.

 

After two years I noticed a slight change when doing the E60.  Old fluid is darker than the new so once you see lighter coloured fluid come out, you know you have cleared that brake line all the way from the reservoir to that wheel.  The first brake fluid change I did on my E60 the fluid must have been in there for four years despite the service book advising differently (selling dealer "changed the fluid" as part of the sale deal I did) as the nipples where really tight and the fluid that came out was almost weak tea in colour as opposed to more like a urine colour (sorry its about the only thing I can think of that matches), the $tealer hadn't done it as two years later the difference between the fluid colour was much less obvious.

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All good posts above regarding pressure bleeders etc.  I have an air compressor so mine works off of that.  

 

I am sure most of you are aware with the caution you are taking regarding the fluid but it is quite toxic and will eat into any painted surface.   I always have a watering can near by to dilute and wash away any spillages.

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9 hours ago, Matthew Ashton said:

I use the Gunson eezibleed pressure bleeder attached to a spare wheel for air pressure. Worked perfectly every time. 

 

That's the one I'm looking at, what pressure do you have the spare wheel at?

 

8 hours ago, Enzo503 said:

All good posts above regarding pressure bleeders etc.  I have an air compressor so mine works off of that.  

 

I am sure most of you are aware with the caution you are taking regarding the fluid but it is quite toxic and will eat into any painted surface.   I always have a watering can near by to dilute and wash away any spillages.

 

I haven't seen one yet that works off my compressor, got any recommendations? That would be my preference over using a spare wheel as it saves pumping the spare back up, plus the air would be filtered.

 

Yes brake fluid is nasty stuff, it's been secured out the way in my garage before taking to the tip this weekend. I've washed down my garage floor after spilling some in the past.

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1 hour ago, 535i Andrew said:

 

That's the one I'm looking at, what pressure do you have the spare wheel at?

 

Gunson recommend 10 - 20 psi so I go midway to 15psi or 100kPa in the modern world.

 

Quote

 

I haven't seen one yet that works off my compressor, got any recommendations? That would be my preference over using a spare wheel as it saves pumping the spare back up, plus the air would be filtered.

 

Yes brake fluid is nasty stuff, it's been secured out the way in my garage before taking to the tip this weekend. I've washed down my garage floor after spilling some in the past.

 

Gunson make a pro version that needs a compressor to operate.

 

Edit: But the Pro version costs £120! so I'll definitely be sticking with my £20 Eezibleed along with a spare wheel (now I have one again within easy reach with Darling Daughter's Fiesta)

Edited by Matthew Ashton

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Thanks Matthew.

 

21 minutes ago, Matthew Ashton said:

(now I have one again within easy reach with Darling Daughter's Fiesta)

 

As long as you remember to blow it backup again!  You would only get the phone call "Daaaaaaaad the spares flat too"

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i see from one or 2 videos online that some people recommend tapping the calipers with a rubber mallet in order to free any air bubbles.

what would you guys say, is it a useful thing to do?

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2 hours ago, Johnboy65 said:

i see from one or 2 videos online that some people recommend tapping the calipers with a rubber mallet in order to free any air bubbles.

what would you guys say, is it a useful thing to do?

 

Have never done that and have never had a problem. Not to say it isn’t a reasonable precautionary action to take. 

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Not a bad shout I suppose, as long as it was a rubber mallet. Or just drive it over rough ground to shake the bubbles to the highest point? 

 

To me the biggest risk of getting air in the system is when you work on the system i.e. when retract the piston in the caliper with the bleed screw open, which is preferable to forcing fluid back up the wrong way into the master cylinder which might also have grit in it.  That's why I bleed out fluid after a brake pad change.  I didn't do this after changing the front brakes on my wifes Focus, got spongy brakes as I had managed to get air in the caliper when retracting the piston.  Bled them and pedal was as it should be.

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