Z3 M44B19 Front Brake Upgrade and Front Wheel Bearing Change
Time – 2 hours per side
Cost – With Upgrading Brakes - £275 – extra for new parts
Bearings only - £75
***Important Read Before You Start***
1) The Brake Disc Retaining Screw is a hex drive and has a tendency to corrode in place, resulting in a stripped drive, so a good HSS Drill Bit and stud extractor kit in the wings may prove handy.
2) The Front & Rear Dust Covers are not included in the wheel bearing kit, and there is a good chance you will damage when removing.
3) All the above items are dealer supply only, and at most dealers order on request only, so ensure you buy these parts and have them ready before you start, as you will not be able to complete the job without them.
4) Full tool and parts list at the end of the document. 46mm Sockets are not readily available over the counter, three leg puller is a must, so order these off the internet, or if you are local I can lend these items out.
5) A list of compatible donor cars should you wish to use salvage parts is at the end of this document.
The process (both Brake upgrade and wheel bearing change)
1) Jack the car up, remove the road wheel and secure the car on an axle stand.
2) Attach a tube clamp to the brake line to the calliper, and loosen the brake line (14mm Spanner) do not remove at this stage. You do not need to do this step if you are just doing the wheel bearings.
3) Undo the two 16mm bolts (Breaker Bar and 16mm Socket) that hold the brake carrier to the hub, remove the brake calliper from the disc. If you are doing wheel bearings only, suspend the calliper from the front spring using the bungee cord. If you are upgrading the brakes then now you can undo the brake line completely by twisting the calliper.
4) Using the correct hex socket remove the disc retaining bolt. If you have a corroded bolt then now is the time to use the HSS Drill Bit and Stud Extractor Kit.
5) Remove the Disc from the Hub.
6) Prise out the front dust cover from the hub using a thin bladed screwdriver or similar, if you are lucky you can re-use. If not then hopefully you already have the new one available.
7) You should now have access to the hub nut. The hub nut is staked to the hub, so take a large flat bladed screwdriver or similar and remove the stake.
8) You can now undo the hub nut using the 46mm socket and a breaker bar, you may need to utilise an extension bar on the breaker bar to get extra leverage.
9) Now that the hub nut is removed you can use the three-leg puller to remove the hub, in some cases the hub will be loose and just pull off, in either case it will leave the inner race in place.
10)With the hub removed you can now remove the brake shield with a 10mm spanner and remove the three retaining screws.
11)With the brake shield removed you should be able to get the three-leg puller behind the rear dust cover, or if you are lucky behind the inner race only, and remove the inner race. If you have damaged the rear dust cover then you should have a new one available if you heeded my advice at the beginning.
12)Now the rebuilding
13)Place the new rear dust cover in place, it will not go on all the way, but don’t worry, as the tightening of the bearing will push it firmly home.
14)Replace or put back on the brake shield 3 bolts, take time to clean your wheel sensor with brake cleaner first.
15)The new bearing should already be packed with grease, if not pack the bearing with grease and push on to the hub as far as it will go. Gently tap the bearing on with the 46mm socket and a soft mallet until you have the threads exposed. You can now wind the bearing on using the new nut from the kit, tighten up to 290Nm.
16)Stake the nut to the hub.
17)Replace the front dust cover
18)Now give your brake disc a good clean with brake cleaner to remove any grease and mount to the hub, lineup the holes correctly and centre with two wheel bolts, apply some copper grease to the retaining screw and fix the disc to the hub, only nip the retaining screw up as it will make it easier to remove next time.
19)Attach the brake calliper (if replacing) to the brake line and tighten up with a 14mm spanner.
20)Push the brake calliper onto the disc and align the holes of the carrier with the hub, replace the bolts and tighten with a 16mm socket to 110Nm.
21)If required bleed the brakes.
22)Jack the car up and remove the axle stand, replace the road wheel, and lower the car to the ground.
23)Tighten the road wheel bolts to 112Nm (recheck after 100miles).
Job Complete
Tools
· Wheel Brace (or 17mm Deep Socket)
· Breaker Bar
· Torque wrench up to 400Nm
· Large flat blade instrument (screw driver, chisel)
· Thin bladed instrument (screw driver, knife blade)
· 16mm Spanner
· 16mm Socket
· Ratchet
· Set of Hex Keys or Sockets
· Stud Extractor
· 10mm HSS Drill Bit
· Drill
· 46mm Socket
· 3 Leg Puller
· 10mm Spanner
· 8mm Spanner
· Brake Bleed Kit
· Hose Clamps
· Bungee Cord
· Trolley jack
· Axle Stand
Parts
· Wheel Bearing Kit (includes Nut) – Part Number - 31226757024
· Front Dust Cover – Part Number - 31206777789
· Rear Dust Cover – Part Number - 31206777788
· Brake Disc Retaining Screw – Part Number - 34211161806
· Brake Shield – Part Number – 34111158985 Left and 34111158986 Right
· 3.0 Vented Discs* – Part Number - 34116864058
· 3.0 Brake Callipers* – Part Number – 34116758113 Left and 34116758114 Right
· 3.0 Brake Carriers* – Part Number - 34106758120
· Brake Pads of your choice – Red Stuff was my choice
· Brake Cleaner
· Brake Fluid
· Bearing Grease
* Compatible Donor BMW vehicles for salvage items
E46:
Details on E46
E46 323Ci Convertible
E46 323i Touring
E46 325Ci Coupe
E46 325Ci Convertible
E46 325i Touring
E46 325i Sedan
E46 325xi Sedan
E46 325xi Touring
E46 328Ci Coupe
E46 328i Sedan
E85:
Details on E85
E85 Z4 3.0i Roadster
Z3:
Details on Z3
Z3 Z3 3.0i Coupe
Z3 Z3 3.0i Roadster