Jump to content
535i Andrew

F10 535i Brake Fluid change (Pressure bleed) DIY

Recommended Posts

My car wanted a full brake fluid change done back in December 2019.  I had changed the front pads and discs in January 2019 and changed the fluid in the front calipers exactly one year ago.  Today I used my Gunson Ezibleed to do a full fluid change on all four calipers.  I had bought 4 500ml bottles of DOT 4 fluid from my local BMW dealer.

 

Tools needed

Gunson Ezibleed kit and means of supply air to it.

17mm socket for wheel bolts

Breaker bar

Torque wrench (capable of 140Nm)

11mm combination spanner for opening the bleed screws both front and rear

Bottle for catching expanded fluid

Expanding rivet removal (trim) tool.

Trolley jack

 

I set up Gunson Eezibleed system using my compressor to supply regulated and filtered air at between 15 and 20 psi as per the Gunson kit.

 

IMG-5357.jpg

 

I had bought a schrader valve that had a 1/4" tapered thread for fitting into an air line.

 

IMG-5359.jpg

 

 

Using the trim tool prize up the three expanding rivets on the scuttle panel above the master cylinder.

 

IMG-5360.jpg

 

Peel back the bonnet seal and lift off the panel to expose the master cylinder.

 

IMG-5363.jpg

 

Unscrew the reservoir cap, I placed it inside a glove to keep it clean.  I then used a turkey baster bought for £1.99 from Amazon to suck out as much of the old fluid into a bottle.  I recovered about 300ml out of the reservoir.

 

Top up the reservoir with new fluid.

 

IMG-5365.jpg

 

 

Fill the Gunson Eezibleed bottle with new fluid and suspend from the underside of the bonnet.  Screw the line from the bottle on to the brake fluid reservoir.  I checked the pressure from the air line using my tyre pressure gauge.

 

IMG-5366.jpg

 

Connect your air line up and check for fluid leaks at all the joints on the Gunson kit.

 

Jack up and remove the rear nearside wheel.  This is the furthest from the reservoir.

 

Set up means to catch the expelled fluid.  I use a my trusted calibrated empty Irn Bru bottle.  I have marked 250ml multiple graduations on the side of the bottle to monitor how much fluid is coming out.

 

Remove the rubber cap over the bleed nipple, spanner pointing to it. 

 

IMG-5367.jpg

 

There isn't much room to wield a spanner between the caliper and various brackets on the rear caliper.

 

IMG-5368.jpg

 

Feed the tube from the Gunson kit thru the ring end of an 11mm combination spanner and onto the nipple and crack open the bleed screw.  I opened the bleed screw perhaps half a turn in total, which required manipulation of the spanner over the nipple to achieve that given the limited clearance.

 

IMG-5372.jpg

 

I collected about 500 ml from each of the rear calipers.  I had to stop and top up the Gunson bottle to achieve that volume of fluid from each of the rear calipers.  Fluid was bubble free and relatively clean.  It was replaced by BMW in December 2017.

 

After the offside rear, I then did the nearside front. 

 

IMG-5376.jpg

 

So much more room to access the bleed nipples on the front calipers.  I bled about 400ml out of each front caliper.  This fluid was replaced a year ago when I changed my front brakes.

 

Last wheel was the offside front. 

 

IMG-5377.jpg

 

The fluid the jug on the right is from the offside front caliper which was replaced exactly a year ago, compare that to the fluid on the left in the bottle which was replaced in December 2017 by BMW, there was no noticeable difference in colour.

 

I will buy more fluid and then use diagnostics to operate the ABS pump now that I've got clean fluid in reservoir and lines.  Pushing ~500ml of fluid out of each caliper ensures I've got clean fluid in the lines and calipers, that was what I wanted to achieve today.  If I had more fluid I would have played with the ABS pump.

 

IMG-5378.jpg

 

Two litres of old fluid were recovered from the car in total. Two litres went in.

 

You effectively loose about 100ml of new fluid as there needs to be a minimum amount in the bottom of the Gunson bottle to prevent air going into the brake fluid master cylinder.  Having a bigger fluid bottle would be handy to limit the number of times you need to stop and refill it.

 

Reset the service on the idrive.

 

 

Share this post


Link to post
Share on other sites
On 12/01/2020 at 21:49, 535i Andrew said:

I will buy more fluid and then use diagnostics to operate the ABS pump now that I've got clean fluid in reservoir and lines.  Pushing ~500ml of fluid out of each caliper ensures I've got clean fluid in the lines and calipers, that was what I wanted to achieve today.  If I had more fluid I would have played with the ABS pump.

Hi Andrew

Thanks for the informative how to guide re changing the brake fluid which I am about to do on my F11. I am confident about the procedure for the brake lines with a Gunson eezibleed as I have done it quite a few times in the past including shearing of a bleed nipple a couple of years ago on another car which caused me a bit of heartache. What I have not done before is replace the fluid in the ABS pump. I have bought a Foxwell NT530 diagnostic unit with this in mind however I am unsure what is required in its operation  and what is required re connection to the ABS pump. Could you shed any light on the procedure?

Thanks

 

Graham

Share this post


Link to post
Share on other sites
22 minutes ago, Graham996 said:

I have bought a Foxwell NT530 diagnostic unit with this in mind however I am unsure what is required in its operation  and what is required re connection to the ABS pump. Could you shed any light on the procedure?

Thanks

 

Graham

 

I have to admit, I've not done it myself either yet.

 

As I understand, once you go thru the service menu mode on the Foxwell it should give you the opportunity to carry out a bleed using the ABS pump.  The Foxwell will tell you to open a particular bleed screw, probably press the brake pedal, press confirm and it will run the ABS pump for a few seconds (it will make a noise as they all do) to purge the pump which will then allow fluid to escape out via that open bleed screw.  Lock bleed screw and then it will ask you to repeat the process on another wheel.  I don't know which wheels it will ask you to carry this out on, so ideally the car needs to be in the air with all four wheels off and an assistant who can either operate the diagnostics or one that can open and shut the bleed screw.

 

It would make sense to carry out this before bleeding the rest of the system so as to get any muck out of the lines after its come out the ABS pump.

 

There are a couple of videos on youtube but none with a Foxwell NT530 and BMW combination.

 

Share this post


Link to post
Share on other sites

@535i Andrew if you have yet you may find a combination spanner for BMW sold on ebay which gives a better access the ring end has a longer crank which gives a lot better access  when undoing/tightening  the brake bleed nipple.

 

Did you manage to remove the filter in the master cylinder to remove that amount of brake fluid first, the reason I asked when I carried a brake fluid change the filter did not want to come out, so consequently I could not syphon  as much of the old fluid as I would have liked before refilling the master cylinder and changing the complete brake fluid in all the lines.

 

I was concerned  breaking the filter trying to remove it, I know they do come out with the help of a small flat bladed screwdriver but this one does not, I have noticed the filter on mine does not go down very far into the brake fluid, so I can't syphon much brake fluid out, our mini cooper brake fluid reservoir filter comes out easy.

Share this post


Link to post
Share on other sites

Thanks @Oilburner, you've reminded me that I have a set of cranked spanners, I should try that next time, but I'll look for a specific spanner as you mention.  I'll need to check if my 'go thru' socket set goes down to 11mm, I could use that.  But my 11 mm combination spanner sits in my tool chest on my work bench within easy access, rather than needing to go ferreting about in toolboxes for a different spanner.  Its only the rear calipers that are tight.  Fronts on mine are quite easy to access. Yes its just laziness on my part. :lol:

 

WRT filter, I didn't even attempt to remove it. I don't like syphoning out too much incase I go too low and air gets in, yes I know it would get bled out but why risk it. When the fluid level drops to the bottom of the filter that's when I stop so as not to drop the level too low and risk air getting in.  I wasn't too fussed by how much I removed as I knew I had plenty of fluid to go in so I could capture 500ml from each caliper so I was confident that what ever was in the master cylinder would have been more than pushed out or suitably diluted with new fluid that it would be o.k.

 

 

Share this post


Link to post
Share on other sites

I think the first time I had trouble with my existing spanners regarding access on the rear brake bleed nipple, then I purchased this one from ebay which is sold for our bmw's it has a longer crank section the only thing I found it's not very easy to get the bleed waste pipe on the nipple, the ring part of the spanner could do with being ground a bit thinner, but I'm reluctant to do that with new spanner it maybe the Sealey brake bleed fluid collection pot I have has got quite a thick pipe which only just about goes on the nipple before touching the ring section of the spanner.

https://www.ebay.co.uk/itm/BMW-Brake-Bleed-Nipple-Spanner-9mm-x-11mm-Wrench-9mm-x-11mm-Ring-Spanner-Germany/172322813982?hash=item281f3d781e:g:r-MAAOSwA29Y4pze

Edited by Oilburner

Share this post


Link to post
Share on other sites

 

I just found the following which explains the Foxwell NT630 ABS brake bleed procedure which I think will be the same for the NT530 and it is how you described it, you definitely require two people as you have to keep the brake pedal depressed and open the front then rear valves. 

 

I also found the following comment which makes the process questionable.  What do you think? My take would be there is still some old fluid in the pump.

 
Abs circuits are normally closed. You only need to bleed them if you change the abs unit. The scan tool opens the circuits and runs the pump/motor to bleed the air out of the abs. You still have to do a manual bleed.

 

 

 

 

In your description you passed 0.5litre out of each rear wheel and 0.4 litres out of the front. This seems quite a lot so I did a quick calculation of the length of brake pipe (internal diameter of 4.75mm) you could fill with 0.5litres of brake fluid and discovered that your estimates are quite correct and my instinct was quite wrong . The implications of this are that I need at least 2 litres of ATE SL6 which is £17 per litre on Amazon so I need £34 of fluid for this job which is starting to make the BMW charge of approximately £100 seem quite reasonable given the faff of removing wheels, setting up the eezibleed etc. I will do it however as I have 2litres in the garage one of which was supposed to be for another car.

image.png.f7ad5ed53f40e53ce6e91b262a3d9a98.png

 

Thanks again for your thoughts

 

Graham

 

Edited by Graham996

Share this post


Link to post
Share on other sites

NOOB question alert!!

 

The wheels need to come off in order to bleed the lines?

 

Mine has just had the brake fluid changed at the dealers at the cost of £70 - i could see the rear end of the car as they were working on it, and i didn't see any wheels come off.......:blink:

Share this post


Link to post
Share on other sites

Hi @Graham996

 

You got me, yes that's the video I have seen before. :lol:

 

I buy the fluid from BMW, it guarantees its the right stuff for my car wrt viscosity and correct DOT rating etc.  I paid £5.88 plus VAT per 0.5 litre from my local dealer in January this year.

 

I go on the 500 ml per caliper as my front calipers are quite big (like on my previous E60 where I first did brake fluid changes) with short lines and the rear calipers are smaller but with longer lines, plus you can "loose" some fluid just from topping up the master cylinder and the fact the Gunson needs a small amount in the bottom as a minimum.

 

It would be good practice to change the fluid in the ABS pump when you change the fluid (every two years after the initial 3 years) so that it doesn't deteriorate and you damage the ABS unit or worse loose braking performance when you really need it!  The BMW procedure activates the ABS pump. 

 

BMW charge me £80 for a brake fluid, its £100 for manual cars as they bleed out the clutch fluid too. £20 per bled nipple basically.

 

Share this post


Link to post
Share on other sites
42 minutes ago, Y15HAL said:

 

 

The wheels need to come off in order to bleed the lines?

 

Mine has just had the brake fluid changed at the dealers at the cost of £70 - i could see the rear end of the car as they were working on it, and i didn't see any wheels come off.......:blink:

 

If up on a ramp then, probably don't need to take the wheels off.  A well practiced tech might be able to access the rears without taking the wheel off, but not me.

 

It certainly explain why FBMWSH AUC cars need their alloys hammering off as despite two brake fluid changes.  The wheels may never have been off if low enough miles to have not worn out the tyres!

 

 

Share this post


Link to post
Share on other sites
24 minutes ago, 535i Andrew said:

 

If up on a ramp then, probably don't need to take the wheels off.  A well practiced tech might be able to access the rears without taking the wheel off, but not me.

 

It certainly explain why FBMWSH AUC cars need their alloys hammering off as despite two brake fluid changes.  The wheels may never have been off if low enough miles to have not worn out the tyres!

 

 

 

Yes, it was jacked fully up - that's a relief then! :) 

Share this post


Link to post
Share on other sites

I haven't actually looked at the ABS pump yet but when the video at 10.09 says open the right front bleeder valve is this a valve on the ABS pump or is it referring to the offside caliper? I suspect it is the pump as otherwise the fluid from the pump will be entering the brake line to the caliper and will need another 400mL of fluid bleeding out. Apologies if this is a dumb question.

Cheers

Graham

Share this post


Link to post
Share on other sites

No that's telling you to open the front offside wheel brake caliper bleed nipple.  He then operates the ABS pump diagnostically and fluid is expelled out the pump towards that wheel.

 

You are dead right it will move old fluid out towards the wheel but not all of it will come out, that's why I think it should ideally be done before bleeding out the system, so you then follow up the ABS pump run with 400-500 ml of new clean fluid behind it.  I don't believe the pump will run long enough for much fluid to be expelled out, but it will be enough to ensure new clean fluid is now located within the pump body.

 

As there is no flow around the brake system as such, not like in an engine cooling system, the same brake fluid tends to sit more or less in the same section of the brake lines or in this case in the ABS pump. 

Share this post


Link to post
Share on other sites

Thanks Andrew

Like you I can see no logic to this as all you are doing is introducing old fluid into the brake lines from the pump if you do ABS pump bleed first.

 

Have a good day

Share this post


Link to post
Share on other sites

Have a look at this video. Apologies that’s is an awful X5  :lol: but he runs the ABS pump and you see mucky fluid coming out. It’s a bit long but interesting enough.

 

 

Share this post


Link to post
Share on other sites

Thanks Andrew I watched this video and it was useful although why on earth you would go to the trouble of purging the ABS and not the brake lines to the rear is beyond me

 

A quick update of what I did

I suggested  earlier in the post that it was logical to activate the ABS  first as this will pump the old fluid into the brake lines which can then be bled out. What I forgot was old fluid will be drawn into the ABS pump making  this  problematic (what do you think Andrew). So  my procedure is, normal  bleed first which I did with an eezibleed (see Andrews excellent description with pictures) 

Doing the above you will have used nearly 2 litres of fluid.

 

I then connected up the Foxwell via the OBD port and topped up the master cylinder to the brim as the abs unit will pump some fluid out via all 4 calipers.

I just followed the instructions presented by the Foxwell (you need an assistant, one to push and pump the brake pedal while the other opens and closes the nipples)) and it took about quarter of an hour and gave the message all completed successfully.

I then got in the car while it was still on axle stands and discovered I had no brakes! (My assistant assumed they would come back when the engine started)

While the ABS was activating I was concerned it was pumping a lot of fluid and this concern was justified as I had just pulled through a lot of air. I missed the instruction to set up your bleeder unit to less than 2 bar. So back to square one the following day.

Manual bleed (lots of air in all of the lines)

Leave the eezibleed on and fill its reservoir to the top (luckily I had some more brake fluid)

Restart the Foxwell and start the ABS bleed

NSR 

Refill the reservoir 

NSF

Refill the reservoir 

OSF

Refill the reservoir 

OSR

All good and resetting the service interval is shown on the American videoclip at the end

 

To be honest £80 at a BMW dealer seems like good value!  I think I will only do the abs at 4 year intervals and an eezibleed at 2 years.

 

 

 

Share this post


Link to post
Share on other sites

Hi @Graham996, so the Foxwell ran the ABS pump for each wheel and not just two in the video you linked to?

 

Yes you would want fresh fluid upstream of the ABS pump before running it so it draws clean fresh new fluid from the reservoir thru itself.

 

 

Share this post


Link to post
Share on other sites

 

Hi Andrew Yes it instructed me to do the near side rear and front and then offside front and finally offside rear. It didn't take long once I new what I was doing. It was a bad moment though when I discovered I had no brakes!

Share this post


Link to post
Share on other sites

Thanks for the info Graham.

 

I think I'll invest in another pair of axle stands so I can get all four wheels off to do that operation in one hit.

 

Still to jack it up via the diff.

Share this post


Link to post
Share on other sites

After watching that E70 X5 video I would not want to do what he did, to pump all that dirty fluid through the front wheel cylinder, I would suggest removing the filter mesh in the brake master cylinder if possible first, the remove as much as possible with turkey baster or what I have used a large animal hypodermic from the vets you don't need any needle just attach a small piece of tubing and suck from the very bottom of master cylinder the old fluid, there is no reason not to remove as much as possible this way, providing you are not opening any bleed nipple, air will not get into the system if once you have removed as much as possible of the old fluid, then refill the master cylinder with new brake fluid, before opening your first bleed nipple.

 

Doing it this way you have greatly reduced any dirty contaminated fluid ever going through the brake wheel cylinders and the ABS pump, that brake fluid in the video clearly shows it had not been changed for many years, because even after three years from a new vehicle brake fluid change you don't notice any colour change, at least I did not at three years and after that at the recommended two-year change it all looks the same colour, as the new brake fluid perfectly clear with no sediment in the bottom of  brake master cylinder.

 

I even wonder if any dealer even goes through the procedure to change the minimal amount of brake fluid in the ABS pump unless the system  has been dismantled, from what I can understand a very small portion of brake fluid stays in the ABS pump more or permanently just going back and forth slightly as the valves open or shut, so not likely to come in contact  with any atmospheric moisture unlike the actual brake master cylinder fluid.

 

After carrying out a normal brake fluid change it would be interesting, then to purge the ABS pump via one nipple and then test that fluid coming out for moisture content, by testing before purging then after my guess is its going to be very minimal if any difference at all.

Edited by Oilburner

Share this post


Link to post
Share on other sites

Well according to this article there can be as much as 5 oz of old brake fluid, left in some ABS modules after flushing & bleeding the brakes with new fluid.

 

Whilst this is an American article doing a rough conversion from UK fluid oz to millilitres =142.07ml, according to them that does represent a fair bit of old fluid left in the ABS module, if our ABS modules are similar and hold that amount of old fluid, then it would be advised to purge the ABS pump module but you are going to need a lot of new brake fluid for each line coming of the module to the bleed nipple.

 

https://www.brakeandfrontend.com/brake-service-bleeding-and-flushing-abs-systems/

 

With a bit of scepticism, of course they could just be stating this to scare their customers into having them change the fluid, now that there are lots of aids to help the average guy do their own  DIY maintenance, the article still makes some interesting reading.

 

At the bottom of this article it does confirm what we all have been saying regarding changing the brake fluid in the master cylinder, then purge the ABS module  to each bleed nipple, but as said its going to take a lot of fluid.

 

https://www.tirereview.com/bleeding-brake-fluid-in-abs-equipped-vehicles/

Edited by Oilburner

Share this post


Link to post
Share on other sites
4 hours ago, Oilburner said:

At the bottom of this article it does confirm what we all have been saying regarding changing the brake fluid in the master cylinder, then purge the ABS module  to each bleed nipple, but as said its going to take a lot of fluid.

 

There's no way BMW go to that length and amount of brake oil when they do it.

 

I wish I could trust they did because that it would be satisfying to know that the ABS and whole brake system had nice new fluid in it.

 

I love a bit of DIY but for £80 I'm going to book into BMW - but now have the anxiety of them washing it with a gritty sponge (I will ask them not to but have read horror stories), damaging my alloys, knocking something out of place and just generally mucking something up on my car....

Share this post


Link to post
Share on other sites
10 hours ago, Munzy123 said:

I love a bit of DIY but for £80 I'm going to book into BMW

 

Yeah but you wouldn't have an opportunity to break out the spanners, trolley jack, axles stands and get filthy mucky with sore knees/back/knuckles working on your car.

 

Save yourself £65 and DIY and not

 

10 hours ago, Munzy123 said:

 have the anxiety of them washing it with a gritty sponge (I will ask them not to but have read horror stories), damaging my alloys, knocking something out of place and just generally mucking something up on my car....

 

:lol:

Share this post


Link to post
Share on other sites

Do you think BMW actually bleeds the ABS pump when they do a brake service? I am starting to doubt it because as I learned you use an awful lot of brake fluid and I would have thought with all the right tools and a 4 post lift its still going to take half an hour which doesn't equate to £80.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×