At AMVIV, I bought new braided SS brake lines, slotted & drilled rotors and Hawk pads for my 03 MCS. I assisted in installing them last weekend.
All week, they've been making a noise kind of like putting a baseball card in the spokes of your bike. It got louder under braking, but was present all the time.
I talked to Steve at Custom MINI Shop (who I bought the brakes from) who suggested that maybe the bolts holding the calipers on weren't torqued to spec. He said the fronts should be torqued to 110 NM (around 81 foot pounds) and the rears to less.
I put the car up and looked around, and all I could find was a 7mm allen key ended bolt. I torqued the rears to the 60 foot pounds the Haynes manual says for the rear caliper bolts with no problem, then moved to the front of the car. Before the torque wrench clicked at 81fp, the bolt head came off the rest of the bolt. Looking at the Haynes manual (I know, I should have done that 1st) I determined that I have now destroyed a caliper guide bolt on my front passenger side caliper.
Now, I assume this is important (else it wouldn't be there) but is it critical? Can the car be driven for a day without it? Also, can I get one of these bolts without buying a whole new caliper? Is the bolt going to be able to be removed from the other side of the caliper without removing the caliper, drilling the bolt and using an easy-out? Do any of you brake guys on here have one of these bolts lying around that you'd be willing to part with?
Help! Please!

Fortunately, I finally got my classic Mini registered this week, so I have another car to get to work in, but next weekend is a Sin City MINI Club drive and the weekend after the car is supposed to be in a car show.

 

I was whincing while reading your post. I knew what was coming. Yes you can buy that bolt from the dealer. As for getting it out, I'd suggest removing the caliper & hanging it from a coat hanger so you don't stress the brake line. Then remove the caliper bracket. Now take that bracket to the bench & get the broken bolt out.

As for your noises. It's my understanding that slotted rotors make some noise. Are the rotors on the propper side of the car? They are directional.

 

The rotors are on the correct side as labeled. I know slotted rotors are a little noisier than the stockers, but these are actively annoying at any speed above a dead stop. If this is normal, I'm going back to factory spec. I've driven several MINIs with Wilwood, Brembo and Stoptech BBKs and none of them sounded remotely like this. Any thought on what kind of money the dealer is going to want for the bolt? And if they are likely to have one in stock?

 

I don't have slotted rotors myself, but have driven cars with them. They aren't as noisy as you describe.

As for the cost of that bolt. It does say BMW/MINI on the box. I wouldn't think it would be more that $10, but that's just a guess. I would hope a dealer would stock it.

 

The guide pin bolts should only be torqued to 30Nm (22ft-lbs) both front and rear. The front caliper mounting bolts are 110Nm (81ft-lbs) and the rears are 65Nm (48ft-lbs). The only things torqued close to 60ft-lbs are the front caliper mounting bolts so I don't know what you are torquing to that amount. MINI says to replace the guide pin bolts during the brake service, but I only change them when they look worn. I assume you tried to torque the front guide pins to 110Nm? If you can't get it out, you may have to drill it out and helicoil it. We may have a guide pin in-stock so let me know.

Steve

 

Yeah, Steve, I tried to torque the front pins to 81 ft-lbs. The rears are now torqued to 48ft-lbs. What makes it even worse is that I even had to go and buy a set of ratchet drive allen keys so I could torque the stupid guide bolts!
Just after I twisted the head off, I left Brad a message about it asking for help. Please let him know what my situation is. Totally my own fault. I have the Haynes book and didn't look at the bloody thing until too late!

 

I don't know how you got them to 48ft-lbs without breaking the rear guide pins, too; that's over double the torque spec. I don't know where you're reading your torque specs from in the Haynes manual, but mine shows the specs I quoted above. I would still like to see pictures of the front calipers and rotors. I'll let Brad know. We were abusing our MINIs at an autocross yesterday so we were not able to answer the phone.

Steve

 

Agro:
If it is the caliper mounting pin that is broken...DO NOT DRIVE ON IT!!
- if you drive without one you are asking for a catastrophic brake failure!!!

Jason

 

No, it's not the caliper mounting bolt, that is supposed to be torqued to the 81ft-lbs I broke this one off at. The bolt I broke is actually the calliper GUIDE pin.
Steve, the figures I got from the Haynes book were for the mounting bolts, but I was using them on the guide bolts. I took a couple of pics of the front driver's side setup but it's really hard to see anything. I'll try again tomorrow, after I get a new bolt.

 

Argh! Just a note of in-abstentia support Agro.
Sorry to hear about the troubles! Hopefully if you just snapped the head off, there will be a stub to grab with a vise grip.

FWIW, after years of wrenching (and snapping off a few water pump bolts :impatient), and watching pros do it, if it isn't huge, and can't be tightened with a 3/8th's, "that's probably too tight".
Watched a guy install spark plugs at a Webb pulley party with a torque wrench - fortunately I stopped him before he snapped the plug off in the head!

 

After reading this, I think I'll go re-torque my caliper bolts.........

 

Either way....you do not want to be driving with a broken guide pin at all. This is still a major safety issue.


Jason

 

Sorry for the confusion. Let me know if there is anything I can do for you. I still don't understand the accelerated wear on the front rotors which is why I'd like some pics.

Steve

 

No worries Steve. Totally my fault. Also, so you all know not to do this, Desert MINI want $30.15 for ONE FREAKING BOLT!
Donovan is going to pick me one up with his employee discount (huge thanks go out to Donovan) but that is an insane price!

 

And after I'm done replacing this bolt, I STILL have to torque the correct mounting bolts to see if that fixes the noise.

 

Be sure to use the torques I listed above. We needed a belt for a repair at AMVIV and got gouged big-time at Desert MINI. I think we get the guide pin bolts for about $15 from Classic, but I will have to check with Brad. It's still a lot of money for a fancy screw.

Steve

 

Yeah, I thknk Donovan gets about 20% off or so, which puts it in the $25 area. But I get it today, which is nice since I'm leaving the car parked until I get it installed. Classic are great for prices, but shipping can add up, and it's not possible to get it here today.
Should I untorque the rear bolts?

 

I'm a big advocate of "if it ain't broke, don't fix it," but that's a lot of torque and I think I would loosen them and re-torque to the correct setting. Also, the rotors are directional so make sure you got the right and left on correctly even though I don't believe that would cause the noise and wear. Also, make sure the surface of the hubs are clean and the rotors sit flat against them.

Steve