| LS1 and other aluminum calipers: Watch out for this problem
I recently installed a set of LS1 aluminum calipers on the front of my 85 IROC. I installed used calipers and had trouble with brake fluid leaking around the bleeder screw threads. This was not thru the port in the center of the bleeder screw where fluid passes when the screw is loosened; just around the threads.
I took a close look at the caliper and found out why it was leaking. The angled sealing surface at the base of the bleeder screw port was almost completely "blown out". It had several cracks and the aluminum appeared to be crumbling. I suspect the prior owner overtightened the bleeder screw forcing the aluminum to "split" like a wedge splits a wood log.
I would think this could happen to any aluminum caliper so watch out when you tighten the bleeder screw. It only needs to be tight enough to seal brake fluid. Put your big wrench away and save your caliper from destruction.
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85 IROC, 355 Superam, Comp Cams/Lingenfelter roller valvetrain, AFR heads, Manley rods, forged pistons/crank, Stewart water pump, Tremec 5 speed, Ford 9" with 3.50 gears, Eibach springs, Koni struts/shocks, subframe connectors, rollcage, 5 pt harnesses | 
