Fitting K-Sport brakes - Long and Pic heavy

I recently fitted some K-Sport brakes to my Z4MR and I promised some members to post a seperate thread about it so here goes.
I don't intend this to be a step by step approach to removing the old and fitting the new brakes as there are many online guides around that cover this, have a search, instead I wanted to concentrate on the problem areas I came across and how I solved them.
So why did I bother? Well, my original brakes weren't working great. The car is 6 six years old now. Braking wasn't a pleasant experience with some judder, mainly due I think to a sticking left front caliper. When they were hot, the brakes squealed like a bitch, sending neighbours and animals to run for cover.
It looked like some yellow stuff pads had been fitted up front with oem pads at the rear. The front rotors looked badly worn, the rears looked ok. So I was looking at new front rotors, refurbing the calipers, new pads and I would also replace fluid and flexible brake lines. When I added up the cost of this, it was a sizeable chunk of money. I decided to put it towards a BBK.
I decided to try and go with K-Sports as there have been very good reports of these in this forum and others.

Ordering

The main K-Sport UK site is http://www.ksport.co.uk
The guys at Apex Performance is the company sitting behind this. If you look on the website you will see that there is a front set listed for the Z4M but no rear set. We decided that the E46 M3 kit should fit but I asked that if it didn't, I could return the total kit which was agreed.
So the order was:
Front 8-pot 356mm Rotor
Rear 4-pot 330mm Rotor
Keeping as close to the existing rotor sizes as possible.
I decided to go just with the K-Sport street pads, and at the moment, I am glad I did
By the time I paid for expedited shipping it came to around £2,400.
It came packed well in four big boxes. Two boxes for the rotors and two had the other parts, calipers etc. You get a brief guide to help you fit it that was good enough for me.



Tools

Removing the old and fitting the new brakes is a fairly simple process if done with care. The problem I had is that although I have a garage with a pit, it seems to be made for something the size of Noddy's car so I would have to do the work outside on my drive. The weather of the last six weeks has been so bad you can imagine what a pain this has been.
Assuming you already have some good socket sets, hex also, hydraulic jacks and stands, addtional bits that can make the job easy are listed here.

Power bleeder - Sealey VS820
http://www.sealey.co.uk/PLPageBuilder.asp?id=20&method=mViewProduct&productid=9320

Accurate Low end torque wrench for bleed nipples and banjo bolts
http://www.halfords.com/webapp/wcs/..._productId_178843_langId_-1_categoryId_165469

High end torque wrench, wheel nuts and big bolts. I had an old one that had seen better days so bought one in Lidls for £16.99

Lug bolt guide
http://www.reverselogic.us/ReverseLogicLimited/Lug_Bolt_Guides.html

Anti sieze grease
http://www.carlube.co.uk/index.cfm?product=121&product_title=Carlube Anti-Seize Grease

Brake Cleaner (1 can per axle should do)
http://www.holtsauto.com/products/print_view/repair-and-maintenance/professional/holts-brake-cleaner

Prize for the most useless tool goes to the Draper brake clamp. The existing BMW rubber hoses are just too tough so don't bother with it.

Rotary tool like a Dremel for cutting the dust shields

Some large washers to put between lug bolts and new rotor.

Some pairs of rubber gloves to protect you from the brake fluid.

I chose to use ATE Super Blue as my replacement fluid as I wanted to flush the system through and see when it was coming out.

Rear Brakes

I will refer to the diagrams on Realoem
http://realoem.com/bmw/showparts.do?model=BT92&mospid=49344&btnr=34_1285&hg=34&fg=10
http://realoem.com/bmw/showparts.do?model=BT92&mospid=49344&btnr=34_1424&hg=34&fg=12
http://realoem.com/bmw/showparts.do?model=BT92&mospid=49344&btnr=34_1500&hg=34&fg=17

The existing rotor and caliper came off very easily. I removed the two large bolts (3 in the caliper diag) holding each rear caliper on. Because the rotor had little or no lip, I just slid the rotor off then supported it. I had no problems with the small hex bolts that hold the rotor on being siezed but I had given all bolts a spray with WD40 the night before. A slight tap with the rubber mallet and off came the rotor.



To fit the mechanics of the new brakes you have the caliper bracket, rotor and caliper to put on in that order. Give the existing hub a good clean first. I used a drill with wire brush attachment. You must get off any crap so the new rotor sits on the hub nicely.
You will need to cut the existing dust shield with the rotary tool so the new caliper and bracket will fit.



Test fit everything, put a few lug bolts in and tighten up a little as per instructions, and have a look to see if the caliper is sitting across the centre of the rotor. It shouldn't be far off. Measure the caliper to rotor surface distance inside the caliper and compare it with what your eyes are telling you. To adjust you can put up to 2 extra washers between the old caliper mount and new caliper mounting bracket. Of the four wheels, I fitted one washer for three of the four corners. Rotate the rotor and see how well its tracking.
Follow the instructions for torquing all the bolts up, then fit the brake pads. I put a small smear of copper grease at every point where metal touched metal, the rear and sides of the pad and the anti-rattle clip. Be careful not to get any on the pad surface.
So now it should look like this.



Now, problems



Above you can see the rear caliper and brake line



Above, a selection of hoses, small original caliper to intermediate bracket hose shown.

The flexible brake lines provided will just not work at all. They are the wrong length and will not fit into the bulkhead to mate with the metal brake line.
Spoke to Kev Duckworth at Apex Performance and he asked for Hel to make some up to my spec free of charge and send them to me. Having a measure with some string I asked for 740mm total length and sent a picture of the existing hose bulkhead end. These were the right length and fitted fine. Probably could have got away with 720mm I think. Its hard to estimate with the banjo fitting.

As you can see from the picture of the old caliper and hoses, there is a bracket in the middle. It is supported twice in its journey from bulkhead to the caliper, once by a plastic clip and also by the metal bracket. I bought some of 6mm rubber lines brake P clip supports off e-bay like this

http://www.ebay.co.uk/itm/P-CLIPS-B...icle_Parts_Accessories_ET&hash=item5649007ce6

To support my new brake line, I took the rubber out of one P clip and used it in the existing plastic cable clip then used one P clip underneath where the old metal bracket used to be. I think it works pretty well.

Pics of new cable path below







The new brake pads dont have a place for the pad sensor to slot into so I just tied these back out of the way with cable ties.

Now I was able to bleed the rear brakes and drive the car.



Stay tuned for fun with the fronts!

Very interesting...

A BBK is on my list of things to do, but at the moment I'd rather continue to put money into my supercharger fund, and accept that I'll need a BBK once that's up and running.

Very good writeup!

One thing caught my eye though... Is the rear calliper really covering that little of the rotor surface? From the picture it seems like it covers only about 70-80% of the rotor ring...

Great write-up with pics

Thanks guys. Yes, Ga41 there is a small inner ring On the rotor that the pads dont touch. Its not the same with the fronts.

Front Brakes

Well, looking back I think I was very lucky with removing the bolts holding the rear brakes on, my luck ended with the lower caliper mounting bolt of the front right caliper. Number 3 in this diagram.

http://realoem.com/bmw/showparts.do?model=BT92&mospid=49344&btnr=34_1282&hg=34&fg=05

I put wd40 on the night before but I still managed to break 3 sockets trying to get it off….grrr…This delayed me about half a day.
In the end I bought a really large tuff socket set from Halfords, some feeze unlock spray and gorrila’d it off….phew!

Like the rear, I had the whole front axle jacked up and the wheels off. I find it easier to do it this way. You can turn the steering wheel to get better access to either wheel and what you do on one, you can move over and do on the other immediately.

I disconnected the front hoses and used the rear calipers and hose just like a plug, sitting them on the ground whilst I removed the front calipers and rotors. Maybe I should have bought some sort of actual plug which would have been more elegant.

After removing the old rotors and calipers, I put the rotor on some old carpet, then just trod on the caliper to push the piston back and separate the two.

The lower parts of the front dust shield need cutting away carefully. It touches the new thicker rotor at this point.



The same procedure as for the rears, carefully fit, align and torque up the new brake parts and it should now look like this.



Same problem again, wrong hoses!
Kev ordered me some 57mm length ones but I think the first delivery may have got lost in the post as they took 3 weeks to arrive. Not a big deal for me luckily as I was travelling a lot for work, the weather was terrible and I had one long weekend in Prague planned :evil:

They finally came.



During this time I had refitted the front wheels and realised how little clearance there was between wheel and new caliper. I had to remove the wheel weights to let the wheel spin on the axle ok.

I decided to fit 12mm spacers all round to increase the clearance between caliper and spoke.

http://www.juiceduptuning.co.uk/shop_viewproduct.asp?ID=47

Got some new locking bolts too…





Put the new hoses on, tested wheel lock, bled the brakes, fitted the rest and went for a careful front wheel balance down at Protyre in Poole. Made sure they used my torque wrench when refitting the wheel bolts

Had a short but lovely drive in the sun yesterday. The manual says to not brake heavily for 300km until they bed in but they feel great….and….no squealing at all so far

The only dark cloud….I currently have the flu so I am pretty much house/bed bound at the moment. Really annoying when the car is sorted and the sun is out :x

I’ll put some better final pics up later.

good effort

is it just man flu hehe

Thanks Taz.
I wish it was just the man-flu variant. This isn't much fun

Felt a little more human so gave the car a quick wash only and headed out in to the sun of Poole, top down of course

The car was driving beautifully, probably felt the best it ever has. At one point some black American muscle car suddenly drew alongside me at some lights and started revving up. Trying to be a fair Englishman, I allowed him a little head start but the Z4M just creamed him when I opened it up, very embarrassing. Don't know what it was, I only ever saw the side of it. I hope I haven't affected UK-US relations















Looking at the pics now, I am thinking, it needs to be a little lower....just so scared of the ferry ramps and speed bumps. Maybe I'll leave it until I get some new suspension next year with the supercharger.

Take care y'all

Nice update. Thanks for the photos. Looks great!

looks really good there, very nice job

One of the best mods I've seen, especially when I look at my crappy stock calipers!

They look really good

Most American muscle cars are loud but no performance. I rented a new Mustang in the US and the accelerator just seemed to make it noisier. Very agricultural to drive too.

Stuart Truman said:

Most American muscle cars are loud but no performance. I rented a new Mustang in the US and the accelerator just seemed to make it noisier. Very agricultural to drive too.

Click to expand...

So true. I've tested one '07 Mustang GT - more or less Zed's perfomance in a straight line, but the mpg turned out almost twice as much; when cornering, there seemed to be only two options - crash or drift.

Thanks guys. It has been said many times before but the Z4M should come with a slightly better brake system by default. The rotors are ok, but the calipers...also I was just tidying some stuff away in the garage and moving the old calipers, I only just realised how bloody heavy they are!

It is a good mod but it wasn't in my plan to do it quite this early on. I think it requires medium skills, commonsense and some planning to achieve.

Yeah, I think this American car was all bark and no bite too Stuart.

the rear rotor is not correct, you can actually see in your full Car pics in the bottom the non swept area, the first pic that shows the caliper and rear rotor you can see something is not right, and the car pics at the end you can already see this unswept area starting to rust... remember rust on the face of the rotor is an mot fail, this WILL eventually rust as its no being "cleaned" by the pad....

FYI, my rotors are completely swept from edge to edge, 100% of the rotor is used, this is defo how yours should be, awesome awesome effort on fitting these yourself, well done...

i think theyve sen you the wrong caliper carrier for the rear, you have a carrier offset for a small rear rotor.

Beedub, Perhaps that's the only one K-Sport make for the rear of the M3... It's wasted potential for sure as the discs look to be of good quality.

Good work on the brakes and nice colour combinations with the black rims. Very nice looking car!

Sent from my Amazon Kindle Fire using Tapatalk 2

good work .

Thanks for the comments....I think you could be right beedub. Ga41 raised this before and I was having a ponder. I'll get back to the supplier and see what they say.