C5 Brake Caliper Bolt Fail
11-24-2015, 09:32 PM
#1
C5 Brake Caliper Bolt Fail
So I noticed a rattling sound on my front driver side the other day. It came and went and happened after I put air in the tires. I thought something might be dragging, but everytime I looked, nada. So I got under it today and noticed I am missing the upper bolt on the driver side front brake caliper! Wondering if my other bolts were loose, I checked the passenger side and noticed that the bolt was on all the way but just spins in place. Obviously, it's not normal to loose a bolt. How tight should these bolts be and has this happened to anyone else? Thanks.
11-24-2015, 09:37 PM
#2
Melting Slicks
Member Since: Nov 2008
Location: Edmonton Alberta, Canada
Posts: 3,146
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Sounds like a DIY brake job gone bad. Someone stripped and did not torque bolts...yikes, makes one wonder what other projects were done to such poor standards?!
Just google for torque values.
Just google for torque values.
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tommie (11-26-2015)
11-26-2015, 08:31 AM
#5
Team Owner
11-26-2015, 09:01 AM
#6
Le Mans Master
11-26-2015, 10:43 AM
#9
Team Owner
The two guide pin bolts are torqued to 23 ft-lbs. It's important that the threads on both the bolt and the female threads in the guide pin are clean and free of any old threadlocker.
While you can replace the bolts (match them at any Lowe's or Home Depot for size and grade) you can get replacement sets at any GM dealer. There are kits that include the bolt, rubber dust boot and guide pins and grease for the guide pins. These are common to most later GM cars. The bolts in the kits come with a threadlocker already applied. In your case with one bolt simply spinning, it sounds like somebody applied way too much torque to the bolt.
If you choose to reuse the existing bolts, clean the threads with a wire brush and apply some BLUE Loctite/Permatex to the threads and torque to spec. I keep some brass rifle cleaning brushes handy for cleaning female threads like in the guide pins. Brushes like .22, .38, and 12 gauge shotgun will cover a lot of female thread sizes
The large bolts that hold the caliper abutment bracket to the spindle can also be reused. Clean the threads and apply the same BLUE Loctite and torque to spec doing it in two steps (1st to 70 ft-lbs then to 125)
While you can replace the bolts (match them at any Lowe's or Home Depot for size and grade) you can get replacement sets at any GM dealer. There are kits that include the bolt, rubber dust boot and guide pins and grease for the guide pins. These are common to most later GM cars. The bolts in the kits come with a threadlocker already applied. In your case with one bolt simply spinning, it sounds like somebody applied way too much torque to the bolt.
If you choose to reuse the existing bolts, clean the threads with a wire brush and apply some BLUE Loctite/Permatex to the threads and torque to spec. I keep some brass rifle cleaning brushes handy for cleaning female threads like in the guide pins. Brushes like .22, .38, and 12 gauge shotgun will cover a lot of female thread sizes
The large bolts that hold the caliper abutment bracket to the spindle can also be reused. Clean the threads and apply the same BLUE Loctite and torque to spec doing it in two steps (1st to 70 ft-lbs then to 125)
11-26-2015, 10:54 PM
#10
Drifting
The caliper guide pin will turn when you attempt to loosen the guide pin bolt unless you put another wrench on the guide pin hex by the dust boot.
Some aftermarket guide pins have just two flats instead of a hex.
Some aftermarket guide pins have just two flats instead of a hex.
