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Brake Caliper Bracket Pins

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#1
tylerbrown

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We have now had two or three brake caliper pin failures on our cars at Road America due to what I believe is the aggressive curbing.

 

Every time I prep a car in between race weekends, as well as between every session at the track at Road America for sure, I pull off the rear brake calipers and make sure that the brake caliper pins do not have any wiggle or that they are not loose. I also Red-Loctite them when they are "new".

 

I have two questions:

 

1. Is it possible to get a stronger pin made or something that would be able to handle the vibrations better?

 

I dont know if this would be persay "SM Legal" but I do not see how it can be a performance advantage in any way if all it is is a stronger Caliper pin so that it does not shear so often. All failures I have had have been within the body of the cast caliper bracket part on the threads of the upper pin. I know of many many people who have had brake failures at Road America, and this is a huge safety hazard. I almost did some serious damage to our cars this weekend when my caliper pin sheared... 

 

2. Would it be a good idea to change the caliper pins after every event to better prevent failure of these items? If the pins have a four weekends to failure rate @RA then replacing them every weekend would prevent them from reaching that point? 

 

Are there other tracks that this happens at?

 

Please let me know your opinions..


Tyler Brown

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#2
Steve Scheifler

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Seems like a good part for someone to custom make. Given how small they are I suspect we all over-torque them even when using locktite so perhaps that is a contributing factor? I’m trying to visualize whether there is physically room to go up a size with a custom part and re-drill and tap the caliper to match.
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#3
Dave Cox

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Tyler - this has been a problem for a long time. I had one take me out of a top 15 position at the Runoffs in '09 about 3 laps from the end. I had not found a solution other than either staying off the curbs (not really an option most of the time) or as you suggested changing them on a regular basis (I think I had been using a 2 events at RA or every year if no RA events type schedule since '09). 

 

Hope you find a better solution than I did.

 

Dave



#4
davew

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Any rebuilt part gets sand blasted prior to paint/coating. Small grains of sand remain in the threads. You need to chase those threads with a tap to clean the threads.

 

You can not have paint, either in the threads or on the mating surface where the pin meets the bracket. Especially if powder coated, the coating gets hot, gets soft and the pin becomes loose.

 

Red loctite is a single use item. You are supossed to use heat to remove. You also need to clean the threads with a tap to remove any chunks of dried Loctite left behind. Removing every session and reloctiting leaves a constant built up debris. Removing without heat may damage the threads.

 

If the threads in the bracket fit loose, you need to replace the pin and or the bracket. After prepping the bracket (see above) thread in the pin  with fingers, back off a little and wiggle it. If it wiggles too much the threads are worn in either the bracket or pin. Sometimes you can get away with just a pin. No amount of loctite will save worn threads.

 

Dave


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#5
tylerbrown

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Dave, I do not remove the caliper pin every session, but I do remove the caliper to gain access to the pin. I only red-loctite the pin when I first get a new caliper, ie single use. I check that the pin does not wiggle when I remove the caliper as I have caught them loosening up once.

Thank you for everything else though.

Tyler Brown

Sneaky Moose Motorsports - Owner

2019 June Sprints - 1st Place

2019 Blackhawk Farms Majors - 1st Place

2018 CAT Majors @Road America 1st Place

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#6
William Keeling

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pins would be open and fasteners are free (other than engine nut and bolts)


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#7
ChrisA

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For theadlocker I like Loctite 246, it is hi-temp, but medium strength. Just hard to find -> Fastenal or online.

Chris

 

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