HELP!! F Body Brake Upgrade

What are the measurements for the F-body caliper bolt. I bought a used pair but it didn't come with the caliper bolts.

Just to clarify I know that its 12mm, but I don't know the length, fine thread or coarse thread, and bolt head size. Furthermore it is not the caliper slide pin bolt that I need info on, but rather the bolt that attaches the caliper bracket to the car.

The thread is course. The head is 1/2 SAE. I used a 6 point socket to get the bolt out. The length is almost 1 inch and 3/8. I have my caliper brackets off due to the caliper slide pin rusted solid in the bracket. Stay away from Cardone replacement parts they are total crap:jerking::banghead:. I had to end up ordering the brackets from the dealer.

Did you have to upgrade to the longer SS brake lines to use the F-body kit? I posted this question before and all I got were links to how other people installed their calipers but never mentioned the need to use the longer SS brake lines.

Are longer brake lines required for the F-body brake upgrade?

No I did not do a upgrade just replaced the rear caliper brackets. I am thinking that I am going to replace the caliper mounting bolts. just to be on the safe side.:2cents:

I am trying to install my F-body brakes, but I can't get the driver side rotor off. I removed the bracket and caliper, and the rotor should slide right off but no luck. I even tried braking it loose with a rubber mallet and PB blaster but no luck. :banghead: Anyone know what to do?

GTP Version 2.0.,

All of your posts have been merged in to one thread re-titled to "HELP!! F Body Brake Upgrade" to cut down on confusion and having multiples threads on the same issue.

Why did you decide to go with the F Body brake upgrade? That is no longer a popular mod so the links we have are no longer valid meaning little or no information on the subject. You'll find out the downside if you ever complete the mod. The Impala/Intrigue 12" rotor upgrade is much better.

Try some more PBBlaster and carefully tapping on the center part of the rotor to get it off. Doesn't make sense since you are in a low moisture/humidity area meaning little or no rust and/or corrosion.

That's what I can't figure out either. I had the rotors replaced back in 2005 (before I really got into cars) from BrakeMax, as they said that they were too worn to turn (I later learned it was total BS.) The passenger side is loose enough to come off, but the driver side seems to be on their pretty tight.

So far I've spent $80 on the calipers, $20 on hardware, and $120 for the new 12in rotors. I know my factory driver side caliper was on its last leg (leak) so I'm still doing this upgrade cheaper than new stock calipers (from dealership not reman/cardone/autoparts store crap) but this mod is getting on my nerves.

Is it safe to use a actual hammer to break it free?

Is it safe to use a actual hammer to break it free?

As long as it is the old rotor and you plan on not ever using it I see no problems with using a BFH.


Just so you know the biggest issue after this mod is done is the amount of brake pedal travel which involves another mod. The dual piston F body calipers use more fluid and the stock brake hydraulic system can't compensate for it.

I got it off....the pricks (and thats the only word I can use to describe them) at BrakeMax put the wrong size rotor on the hub and forced it on. I looked at the lug spacing and noticed that they were all off center. I drilled several holes around the lugs to give me more play, and then smacked it with a hammer.

Does this mod put additional strain on the braking system? Is this why the SS lines are recommended (for lesser brake line expansion)? This is the first time I have heard any downside with the F-body upgrade.

The reason for the ss lines it will not rust out like the regular steel lines do. Just like the lines did on my GP.

The rotor should have been loose and free floating with out the caliper and the pads. I had to replace the rotors on the wifes Explorer. I had to use a sledge hammer to get the passenger rotor off. That was a nightmare in itself. The parts monkeys got me again the caliper bracket the was not the right one. I hate the parts monkeys.

That is why I do not trust places like that, even Midas is a rip off. My friend Jeff brought hes car to Midas. They told him that he need new rotors calipers the brackets all four sides. Also the muffler system was leaking and would not pass the vehicle inspection. The total price for all the work quoted, was almost a grand. The only problem With that is that he had taken to the state inspection, a couple of days before he had taken his car to Midas, and it passed. So he knew that they were full of crap. He told Midas to put the car back together. Only two the lug nuts were put on correctly. I was glad I went with him to pick up his car. I have to wonder if the lug nut studs would have snapped off. Good thing I had enough tools in my car to tighten up the rest of the lug nuts.

It sounds they installed a disc rotor with a 5X114 bolt pattern. :twak:

Anyways the primary reason(s) for SS braided brake lines is:

The SS outer braid and inner teflon hose reduce expansion supposedly giving the brakes a firmer feeling. Next the braiding protects the hose from road debris. Finally for looks.

Well so far I'm really happy with the brake upgrade. Braking is more responsive and the car feels light on her toes (just like everyone said it would). I have SS brake lines in the mail now so that will only add to the responsiveness.

Also just for the record and for anyone referencing this post, the bolt for the F-body isn't 1/2 SAE as stated above its a M12 with a 19mm hex head with 1.75mm turn thread thats 35-40mm in length, but most importantly 10.9 class steel (equivalent to grade 8). Ace hardware has them as well as McMaster-carr.com

That is where I got the caliper bracket bolts was from ACE Hardware.

Well its funny...after driving about 20 miles now I think I am understanding why my car would slowly veer to the left while driving; the caliper wasn't completely releasing from the rotor, applying pressure and causing the wheel to slow faster while coasting.

My car starts off the line faster now and stays straight while coasting. I never thought to check the calipers, but since they weren't noticeably wearing down the rotor, squeeking, and since the stock calipers naturally wear down one side of the pad slightly faster than the other, it only goes to show you that you may never know you have a problem until you mod your car.