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Author Topic: Front Brake caliper replacement - anyone done one?  (Read 469 times)

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May 03, 2018, 07:38:21 PM

X5Sport

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Front Brake caliper replacement - anyone done one?
« on: May 03, 2018, 07:38:21 PM »
My front right brake caliper is misbehaving and I am going to replace it with a Pagid service exchange unit.

Has anyone else done either an E70 or E71 front caliper?

Any ‘gotchas’?

Does anyone have the correct torque settings for the slide pins?  It looks as if it simply a case of ...

Wheel off
Pads out
Loosen fluid reservoir cap
Force back that piston
Undo the two slide pins
Clamp the brake line
Remove the brake line and protect the end
Attach line to new caliper
Remount and tighten slide pins (assuming they are clean enough) to correct torque
Install pads
Declamp pipe and open bleed nipple to allow fluid to fill behind
Bleed brakes via pedal movement
Clean all, ensure caps and covers are in place
Refit front wheel



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May 04, 2018, 07:47:47 AM
Reply #1

celica

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Re: Front Brake caliper replacement - anyone done one?
« Reply #1 on: May 04, 2018, 07:47:47 AM »
Sorry can’t help as mechanic did it for me

I used biggred via eBay kit and well packaged and made items

May 04, 2018, 10:12:51 AM
Reply #2

Alan Gunn

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Re: Front Brake caliper replacement - anyone done one?
« Reply #2 on: May 04, 2018, 10:12:51 AM »
Looking like you know the procedure.
I also have used Biggred several times get the number of their site then go on eBay as the price is better sounds daft but true.
Also their delivery is fast as well.
I normally do a rebuild as a refurbished is fitted with the refurb kit but it's shiny lol but not for long and very easy to do plus save some hard earned.

May 05, 2018, 07:21:54 AM
Reply #3

DavetheBlade

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Re: Front Brake caliper replacement - anyone done one?
« Reply #3 on: May 05, 2018, 07:21:54 AM »
Replaced a seized nearside front a month or so back. Sourced replacement from Eurocar Parts and after their usual discounts was around £100 and helpfully came with sachets of lube for guide pins etc.

Your procedure is how I did it differing only in back filling the caliper with brake fluid with a big syringe and bleeding the brakes where I used vacum bleeder. All in job took around half an hour with the easist bit being swapping the calpiers over.

Good luck.

May 05, 2018, 08:50:02 AM
Reply #4

X5Sport

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Re: Front Brake caliper replacement - anyone done one?
« Reply #4 on: May 05, 2018, 08:50:02 AM »
Cheers all.  I’m waiting for ECP to deliver and the syringe tip is a handy one  :)

I don’t have access to a vacuum bleeder but I do have an Eezi-Bleed which I used successfully on the E46 with the feed tyre pressure reduced to about 12psi, otherwise it will be the good old fashioned “Up...........Down” system.
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May 05, 2018, 09:10:54 PM
Reply #5

X5Sport

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Re: Front Brake caliper replacement - anyone done one?
« Reply #5 on: May 05, 2018, 09:10:54 PM »
ECP have let me down and not processed the order so no caliper, on top of which our venerable E46 has thrown a curve ball with the DSC and handbrake lights both coming up in amber!  It seems to have lost contact with the No2 pressure sensor on the master cylinder and the ABS sensor on the rear axle!  Carly has identified both so at least I know what is wrong.

Both are apparently common faults on that model and need fixing.  Everything still works but isn’t perfectly happy.  It will have to go into an Indy though as getting at the sensors is fiddly with large hands, and bleeding the brakes without the proper kit can be fraught.  Have to let a proper expert sort this.  Not bad as apart from a new starter three years ago, these are the first problems we’ve had on a 13 year old car.
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May 05, 2018, 10:44:49 PM
Reply #6

amacman

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Re: Front Brake caliper replacement - anyone done one?
« Reply #6 on: May 05, 2018, 10:44:49 PM »
Typed a long post and got timed out so here goes again with a shorter post .

See yon eezi bleed thing , I never fill that with fluid as per the instructions .thousands of very small air bubbles can get into the system .
I fill the vehicle reservoir as much as I dare and attach the empty eezi bleed kit to pressurise the system for a one person job . Only hassle is the air hose is not long enough for tall vehicles and not all that good for any vehicle .

Fill the reservoir slowly and carefully otherwise small air bubbles can be produced whilst pouring .

I use a motamec bleeder with built in hand pump which does not require a separate pressurised air supply and again I do not fill this with fluid and only use it to pressurise the system for a one person job .
https://www.motamec.com/motamec-brake-clutch-bleeding-system-fluid-bleeder-2-5l-90-deg-angle-adaptor.html


I`ll post back if I come across the caliper pin torque setting .




May 06, 2018, 01:13:45 AM
Reply #7

amacman

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Re: Front Brake caliper replacement - anyone done one?
« Reply #7 on: May 06, 2018, 01:13:45 AM »
Guide pins seem to be 30 - 35 nm on all front Bmw systems
https://xoutpost.com/images/articles/196/frontbraketis.sized.jpg

DIY on E53 X5 will be similar
https://xoutpost.com/articles/x5/brakes/9584-bmw-x5-complete-brake-job-diy.html

Tip regarding the pressure bleeders, I leave the system pressurised for a while every time I top up the master cylinder in order to squeeze out any air bubbles from the fluid . The fluid can’t be compressed but the pressure helps getting the bubbles out . I always let the pressure off again for a few minutes and then re pressurise before bleeding the system .
If you have a big syringe use it to draw as much old fluid as you dare from the master cylinder and then top up with new fluid . I top up from a clean very small jug with a pouring spout .

When changing pads or the Caliper . The practice of pushing the pads / pistons back will push dirty fluid back through the system . The dirtiest fluid will usually always be in the calipers so I always clamp the flexi hose first and then attach a suitable hose to the bleed valve leading to a container . Open the bleed valve and then push the pads / pistons back thus draining fluid into the container .

May 06, 2018, 01:50:36 AM
Reply #8

amacman

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Re: Front Brake caliper replacement - anyone done one?
« Reply #8 on: May 06, 2018, 01:50:36 AM »
More ramblings ,
As you are replacing the caliper there is probably no need to push the pistons back except where the discs are worn with a lip on the outer edge preventing removal of the pads but maybe you could just remove the guide pins and gently wrestle the caliper off with the pads still in place . The outer pad will likely fall off anyway ( remember to remove the retaining spring first , some calipers have a sort of plate on the outside ) the inner pad has three spring prongs holding it into a hollow in the piston so it should stay in place .
The caliper needs to be off in order to unscrew the flexi hose anyway but be sure to slightly loosen the flexi hose from the caliper before you loosen anything else .
The new caliper will need to be wound on to the flexi hose just be sure it’s all clean . The hose can be semi tightened with a spanner ( proper brake tools or crow foot wrenches are best ) at this point and properly torqued when the caliper is fully assembled and bolted back in its place .
Always a good idea to have at least one spare pad retaining spring when doing brake jobs although the old ones can be bent back into shape easy enough if they are not too corroded .

May 06, 2018, 03:04:14 AM
Reply #9

amacman

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Re: Front Brake caliper replacement - anyone done one?
« Reply #9 on: May 06, 2018, 03:04:14 AM »
A soft plastic scouring pad such as one would use in a kitchen is usefull to gently clean the guide pins just don’t go rough otherwise they can be scratched . The only contamination usually found on them is rubber from their bushes .
The guide pins should be fitted dry and clean . I have been known to sometimes apply a very slight rub of red rubber grease to the pins if the bushes seem a bit sticky .

May 06, 2018, 08:13:14 AM
Reply #10

X5Sport

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Re: Front Brake caliper replacement - anyone done one?
« Reply #10 on: May 06, 2018, 08:13:14 AM »
Very useful to know, thanks for the tips and taking the time to put this together  :D

Like you, I fill the reservoir and then apply pressure - and good point about the hose length, mine was bought to service my Vauxhall Cavaliers in the 1990’s!  They were a little nearer the ground!  A bicycle wheel at higher pressure can help but I know BMW need to have the pressure kept at below 20psi to avoid damaging anything.  Vacuum is the preferred method on these cars.
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May 06, 2018, 05:45:44 PM
Reply #11

amacman

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Re: Front Brake caliper replacement - anyone done one?
« Reply #11 on: May 06, 2018, 05:45:44 PM »
The guide pins usually require a 7mm hex / allen key . Most tool kits don`t have that size included .
Vacuum method is slow if using a hand pump . Air is usually drawn in through the bleed valve threads when loosened making you think there is air in the system and it means you need to operate the hand pump more .


Regarding vacuum pumps . After I have completed a fluid flush / system bleed I will attach a vacuum pump at low vacuum to the master cylinder and leave it there for hours as it draws air from the entire system .
Just remember the caliper pistons will be pulled back during this process meaning when you eventually apply the brake pedal that it will go to the floor until you have fully pumped pressure back into the system .

You will never regret buying the motamec pressure bleeder because adjusting the pressure is just so easy compared to the eezi bleed where you need tyre inflator to adjust pressure on your chosen air supply .


Might all seem a silly faff to most folk but I am not most folk and I like things done the best they can be .

May 12, 2018, 01:04:42 PM
Reply #12

X5Sport

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Re: Front Brake caliper replacement - anyone done one?
« Reply #12 on: May 12, 2018, 01:04:42 PM »
So, which brake fluid ‘family’?  DOT4 or DOT5.1?

I believe the system is filled with DOT 4 and that is what I would choose unless there is some reason to go to DOT 5.1.  As I don’t hoon the car around DOT4 looks to be fine.

I know DOT 5 is an absolute no no as the system has both ABS and is likely filled with DOT 4 already.  Silicone fluids don’t mix, increase corrosion risk due to being Hydrophobic (causing water drops to sit against pipes), and don’t play nicely with ABS due to compressibility being higher that DOT 4/5.1.
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May 19, 2018, 08:24:33 PM
Reply #13

X5Sport

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Re: Front Brake caliper replacement - anyone done one?
« Reply #13 on: May 19, 2018, 08:24:33 PM »
Answering my own question, BMW TIS quotes DOT 4 only.

Job done and I am beginning to think I’m getting too old for this s...!  Parts on these cars are xxxxxxx heavy!

Access to the brake reservoir needs a 13mm socket to undo each 1/2turn catch (4 of).  Whilst you are in that area it will be well worth vacuuming all of the dead leaves etc that collect in the hole.

Replaced both front discs, pads, wear sensor, spring retainers (recommended for cars over 48 mths) and off side caliper.  Pads have to be the fiddliest job I have ever done on any braking system on any cars I have owned!

Great videos on YouTube cover the E70 with enough similarity to convert to the X6.  The biggest difference being the floating caliper is a single piston in the X6 (up to the 40d).  They also show you the key places to put brake paste/copper ease etc.

As expected the discs needed a little ‘persuasion’ with a wooden block, brake cleaner and an adjusting stick (hammer).  Set screw is 16Nm torque (I used a bicycle repair torque wrench) and I put a smidge of copper ease on it.

I dismounted the calipers as complete assemblies (you need an E18 Torx socket) rather than mess with the slide pins.  You will need a decent length bar on the socket to break the threadlock hold.  Getting them back on again with just two hands is a little challenging.

Cleaned the slide pins with Scotchbrite (other brands are available) as it gets the crap off without damaging the surface of the pins themselves.

Bought and used the suggested Motamec bleeder as suggested.  Brilliant suggestion as it really does make things easy, as was not filling it with fluid just used as a pressure reservoir.  :thumbsup: :bigthanx: :ok:

I did replace all 4 caliper carrier bolts with new and used a medium strength threadlock (as suggested on line, and used by the factory) although they aren’t ‘stretch’ bolts I thought it best to be safe.  You need a torque wrench to refit.  110Nm.

All parts from ECP for just under £280 (inc £35 surcharge which I’ll get refunded next week).  Used Pagid for everything.

8 mile test circuits and all seems OK.  Haven’t reset the pad service life yet as the on line suggestion didn’t work due to the wear sensor not having been tripped (or else I did it wrong  :-[ )

Although the wear sensor had not tripped and the outer pads on both sides looked fine, both inner pads were almost out of material so beware if yours look good on the outside.

Thank you for all your help  :)

Not sure how much I saved, but I’m pleased with myself.  Now going off to find out how to unstiffen these joints!

Oh........and I missed the wedding and the FA Cup too.   :))
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