So today I settled down to replace the M5′s front brakes. When I got the car, some two and a half years ago now, I noted that the front discs were quite crusty and lipped, so now seemed like a sensible time to do something about them.
Generally speaking, the brakes and wheels are just some of the parts of the car that prevent it from looking really smart. I therefore decided to not only replace the brakes, but also give the calipers and carriers a decent clean and a paint, and I’ve also booked the car in to have its wheels refurbished next month.
So straight to the usual routine – car up, wheels off…
Despite the discs being rather corroded, I was pleased to note how well maintained the various bolts were – they were all a pleasure to operate, and showed no sign of the car being 10 years old.
I had a little bit of a mission finding the brake fluid reservoir – turns out it’s under the driver’s side microfilter. I’ll probably make a dedicated post on this matter in due course to make this information easier to find for others, but for now, here’s this photograph:
Having marvelled at how well maintained the driver’s side brake assembly was, I was of course massively stitched up by the other side. The M5 has not one but two retaining bolts to hold the disc to the hub, and unfortunately one of those heads had been previously thoroughly rounded. There was just no way I could get a tool of any sort to bite in there – I even tried hammering in a star key. So I took to drilling it out.
Several hours later I was clearly getting there but was running out of daylight and warmth. This was extremely disappointing, so I did what I always do at such a stage, and I gave up and called Alex. Regular readers might remember that Alex saved my arse when I couldn’t replace the 330d’s propshaft donut. This time we discussed the issue, and I explained that I was patiently drilling the bolt out. Alex told me to man up and use an angle grinder, and 5 minutes later I was done. Good advice!
So then I was finally able to crack on again. I wired brushed and solvent prepared the calipers and carriers. Previously:
A reminder of what the brakes looked like this morning:
Crusty! This evening:
That’s as far as I’ve got – bad light stopped play. Tomorrow morning I’m off in the tractor to BMW to collect new retaining bolts, and I’ve also elected to replace all the wheel bolts – once the alloys are refurbished this should really make the car look much smarter.
I had previously mentioned that I was hoping to fit drilled discs to the M5, but unfortunately C3BMW have stopped stocking those as they say they received too many complaints about them warping. The only other options were > £2,000 for full on multi-pot caliper conversions. Since I don’t actually track the car, and I haven’t got those sort of funds available(!), I’ve therefore fitted BMW parts.
It’s a bit of a shame really, as when viewed in perspective with the rest of the car, these brakes don’t really look up to much:
Could be bigger, or drilled or generally a bit more bling, no? 400 horse power after all sir. Oh well, at least it’s all clean and tidy now. I hope to be back on the road by lunchtime tomorrow!