2003 Silverado - Convert single piston rear brakes to 2 piston?

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My 2003 regular cab long be 4X4 base model 4.8 Silverado has a sticky rear caliper piston at 45K miles. The system has thinner rotors and single piston calipers that comes on non limited slip axles. Thinking about replacing system with the two piston calipers and thicker rotors that come on limited slip axles. It seems it is a bolt on swap requiring new caliper brackets, calipers, pads and rotors. Not sure if the hoses need to be replaced. Due to stuck caliper and parts needed to repair system, it'd be a good time to do it if it is indeed a worthwhile upgrade. I've heard suggestions researching that maybe the master cylinder and proportioning valve are different and may not function properly with these parts from the old system. It may be that ABS takes care of this and the original parts work just fine. Know if this swap is a simple, straightforward, and worthwhile as it seems?
 
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I can't imagine it's a worthwhile upgrade. How much of your brake force comes from the rear on a pickup truck. Most braking systems are limited by traction, not by the pads, rotors or calipers. If you are tripping the ABS during a panic stop with what you have, you really don't get anything more by changing to a two piston caliper. Well, you get one thing, 2x as many components to potentially fail.
 

ledslinger

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Originally Posted by javacontour
I can't imagine it's a worthwhile upgrade. How much of your brake force comes from the rear on a pickup truck. Most braking systems are limited by traction, not by the pads, rotors or calipers. If you are tripping the ABS during a panic stop with what you have, you really don't get anything more by changing to a two piston caliper. Well, you get one thing, 2x as many components to potentially fail.
GM didn't put the assuredly more expensive 2 piston system with larger rotors on for no reason when the duty went up with the limited slip option and increased GVWR. They went with the 2 piston system because engineers concluded it increased braking ability, possibly mainly when loaded or towing.
 
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True, but that's a different vehicle with a different tow rating. Since you are only replacing the brakes, IIUC, you are not looking at upgrading the tow/cargo capacity of the vehicle. Unless you are replacing EVERYTHING, your tow and cargo rating isn't going anywhere. So I stand by my assertion that for the vehicle as designed, for the load it is designed to haul or tow, you are not getting anything with this change. I suspect you would need to do more than just change the brakes to increase what the vehicle can safely haul or tow. You have springs, the axle you mentioned and who knows what else, tires, ECM programming and so on.... Again, the guideline I provided still applies, if you engage the ABS during heavy braking, you are not limited by brake force, you are limited by traction. You will not get any more brake force by changing brake components as the traction remains the same. But hey, if you want to do it, just see if parts such as the rubber brake hoses and the proportioning valve is different for this set up. It's your time and money. If you are looking for something to do, knock yourself out. I think think you have a solution in search of a problem that isn't really there.
Originally Posted by ledslinger
Originally Posted by javacontour
I can't imagine it's a worthwhile upgrade. How much of your brake force comes from the rear on a pickup truck. Most braking systems are limited by traction, not by the pads, rotors or calipers. If you are tripping the ABS during a panic stop with what you have, you really don't get anything more by changing to a two piston caliper. Well, you get one thing, 2x as many components to potentially fail.
GM didn't put the assuredly more expensive 2 piston system with larger rotors on for no reason when the duty went up with the limited slip option and increased GVWR. They went with the 2 piston system because engineers concluded it increased braking ability, possibly mainly when loaded or towing.
 
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Well then, look up the master cylinder and proportioning valve for these two different options and see if they need changed. However, you only told us about a failure, not whether you need a rear brake upgrade. Are the front brakes the same then? I don't see what you're after unless you do plan on towing a significant load. ABS won't take care of a mismatched brake setup. It'll come on too early, and you're no better off than with the standard duty brakes unless hauling enough of a load. Are you sure it is the caliper piston and not the slider pin corroded from inadequate lube? I am not trying to talk you out of the upgrade, but replacing a caliper is a quick, easy job if there isn't insurmountable rust, so it's not like it's a tiny leap to research and replace the whole thing, on both sides and possibly the master cylinder and proportioning valve too, more like multiple times as much work.
 
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Good point on the master cylinder, I hadn't thought about that. My thought was if you don't get it right, you'll end up with LESS rear braking if the "upgrade" calipers have a greater volume to fill and the brake application doesn't provide enough fluid to get the same braking. If done wrong, you could end up with less, not more braking.
Originally Posted by Dave9
Well then, look up the master cylinder and proportioning valve for these two different options and see if they need changed. However, you only told us about a failure, not whether you need a rear brake upgrade. Are the front brakes the same then? I don't see what you're after unless you do plan on towing a significant load. ABS won't take care of a mismatched brake setup. It'll come on too early, and you're no better off than with the standard duty brakes unless hauling enough of a load. Are you sure it is the caliper piston and not the slider pin corroded from inadequate lube? I am not trying to talk you out of the upgrade, but replacing a caliper is a quick, easy job if there isn't insurmountable rust, so it's not like it's a tiny leap to research and replace the whole thing, on both sides and possibly the master cylinder and proportioning valve too, more like multiple times as much work.
 
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Do the rears lock up easily? if so, no need to upgrade, but if the fronts are always the only ones to lock you could decrease stopping distances with more powerful rear brakes. On most FWD cars the rears are far under dimensioned (60/40 weight distribution, but 80/20 brake bias at best), but for a pick up with no load over the rears that's likely not the case.
 

ledslinger

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I'm not sure about this, but I think with the advent and development of ABS, there may have been a shift to more rear wheel bias in proportioning. The ABS will take every wheel to maximum braking regardless of built in proportioning, and with more application of rear brakes during normal stops, there could be less squat. I think this may be the case because I've been hearing drivers report rear brake pads on newer cars wearing out before fronts.
 
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Gm stopped doing rear disc brakes on 1/2 tons pickups in 2004 and didn't start again for 10 years or so for a reason. Those disc setups sucked. The pins in the rear caliper mounting bracket liked to freeze up on my 2003. In 2007 I had to replace the brackets because the pins were stuck solid. Year later had to loosen them up again and I think they were froze again then next year also.
 
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Originally Posted by dfarr67
Converted a 1989 Silverado to 2005 Suburban 4 disc, a little bit of an improvement wink
Dragging your foot would have been an improvement on that body style.
 
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