FC Single Piston Calipers on FB?
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Full Member
Joined: Feb 2014
Posts: 137
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From: Minnesota
FC Single Piston Calipers on FB?
I bought an '87 parts car for the engine, and was curious if it was possible to run the brake system on my '83 GSL. First things first, is it worth the effort for just the single piston calipers and rotors? All write-ups I've seen are specifically for the 4-pot brakes but seeing as I've already got an FC destined for the junkyard why not pull off what can be saved? My FB will be a street car for now, and for a while I presume so I don't need any outrageous brakes. Just an upgrade from the stockers. If it would be a worthwhile upgrade, does anybody have any tips?
I've contemplated doing the full front subframe swap, but I'm not entirely sure if its necessary for me.
I've contemplated doing the full front subframe swap, but I'm not entirely sure if its necessary for me.
Old [Sch|F]ool
Joined: May 2001
Posts: 12,856
Likes: 568
From: Cleveland, Ohio, USA
I don't know about GSL-SE, but single piston FC and '81-85 12A calipers are interchangeable. My car has an FC caliper on one side and 12A caliper on the other, actually.
Only the actual caliper is interchangeable, not the hanger or pads. I forget if you need to use the pin that goes with the caliper or the pin that goes with the hanger, but the pins are different too. (Probably goes with the hanger)
Single piston are all 2" bore, rear calipers are all 1 3/8" bore, four pot (FC and FD) are all the same bore too (I think also 1 3/8")
Only the actual caliper is interchangeable, not the hanger or pads. I forget if you need to use the pin that goes with the caliper or the pin that goes with the hanger, but the pins are different too. (Probably goes with the hanger)
Single piston are all 2" bore, rear calipers are all 1 3/8" bore, four pot (FC and FD) are all the same bore too (I think also 1 3/8")
Thread Starter
Full Member
Joined: Feb 2014
Posts: 137
Likes: 1
From: Minnesota
I don't know about GSL-SE, but single piston FC and '81-85 12A calipers are interchangeable. My car has an FC caliper on one side and 12A caliper on the other, actually.
Only the actual caliper is interchangeable, not the hanger or pads. I forget if you need to use the pin that goes with the caliper or the pin that goes with the hanger, but the pins are different too. (Probably goes with the hanger)
Single piston are all 2" bore, rear calipers are all 1 3/8" bore, four pot (FC and FD) are all the same bore too (I think also 1 3/8")
Only the actual caliper is interchangeable, not the hanger or pads. I forget if you need to use the pin that goes with the caliper or the pin that goes with the hanger, but the pins are different too. (Probably goes with the hanger)
Single piston are all 2" bore, rear calipers are all 1 3/8" bore, four pot (FC and FD) are all the same bore too (I think also 1 3/8")
It sounds like I should just wait and put the four pots on when I get the money.
Old [Sch|F]ool
Joined: May 2001
Posts: 12,856
Likes: 568
From: Cleveland, Ohio, USA
Any upgrade would be due to pad size or rotor diameter/mass. The calipers themselves are functionally identical. (As noted - they use the same pistons, therefore there is no hydraulic difference between a '91 single piston and an '81. Or a '79 for that matter, same bore just different design)
I have a FC frontend on my GSL. I feel that the 12A brakes were better. This is probably a pad composition thing.
Heck, the 4-piston calipers are just about identical hydraulically. More pistons but smaller and the sizes cancel each other out.
I don't think it would be easy at all to try to use the entire FC caliper due to differing designs, so the only thing you'd be able to use would be the caliper body, which would be a lateral move. Maybe keep them as spares. I seem to have the worst luck with calipers rusting and the pistons siezing in the bore...
I have a FC frontend on my GSL. I feel that the 12A brakes were better. This is probably a pad composition thing.
Heck, the 4-piston calipers are just about identical hydraulically. More pistons but smaller and the sizes cancel each other out.
I don't think it would be easy at all to try to use the entire FC caliper due to differing designs, so the only thing you'd be able to use would be the caliper body, which would be a lateral move. Maybe keep them as spares. I seem to have the worst luck with calipers rusting and the pistons siezing in the bore...