Ok. The truck now has a new caliper on the passenger side rear wheel and new pads. After an intense 40 mile test drive, the brake pedal seems to stop about 1-2cm above the same level as the gas pedal is at when it is at idle. Sometimes it is very firm, sometimes it is soft and goes down to the same level as the gas pedal (not very often), but no matter how much pressure is required to apply the brakes, it seems to have a consistent range of motion between fully released and fully applied, despite the pedal pressure required being different every few brake applications. But the truck stops nonetheless without incident. Once every few brake applications it is a bit soft, but no warning lights show up and the pedal does not go to the floor, so I am happy with that. I even found a back road a few miles from my house that is half a mile long with no potholes and has no curves. I managed to take it up to 40 mph twice, hit the brakes and stop normally. The ABS didn't kick in, but the front of the truck dropped an inch and bounced sharply when the truck stopped. The brakes seem to work great, except for the 1 out of 10-20 brake applications where it starts to feel a little soft, but it automatically corrects itself somehow and gets very firm. The pedal feels better than before the caliper replacements.

The total list of parts replaced on the brake system in less than a week and a half:
1 master cylinder (as far as we know it is brand new and not OEM, current condition unknown, but it is nearly full)
2 rear calipers (both got stuck 1 week apart from the other)
2 sets of rear brake pads (right side replaced twice)
1 rotor replaced, 1 rotor turned (right one was caught early enough to save the rotor)
1 brake fluid flush
countless brake bleeds from nearly all the repairs

Hopefully I can learn to start to trust the truck again because even after all this, I am still afraid that the next time I step on the brakes, the same thing will happen again and I will have to use other means to stop the truck to avoid an accident.

 

The pedal force and range of motion I am talking about in my previous post: Is that normal or do I have ANOTHER problem with the brakes? The pedal seems to stop at more or less the same place, but it is the differences in pedal force required to stop the truck and the slightly different stopping distances each time I hit the brakes I am talking about. One second, it might be very firm and the truck would stop on a dime, another second, the pedal might get a bit soft and it might take a bit longer to stop, but it does stop ok with no pedal to the floor or warning lights. Hard to believe I have driven it 1000 miles since the master cylinder has been replaced even though it was in the shop or undriveable due to the stuck calipers (I just didn't drive it unless it was to the repair shop because I didn't want a fire or another brake failure after I noticed it) for much of the time between when that was done and today.

 

I was always told if you replace one caliper or wheel cylinder on and axel, do the other side also. As for your machinc telling you he's never seen the one side go bad just after the other. Well I've seen it happen a few times.
The changes in the pedal tell me that you've got a bad bleed . With having the system apart so much and being the least expensive, I'd re-bleed the lines. Bleed the whole system not just the back. If you still have a changing pedal then it's something machanical???
Any time you have a car repaired it's a good idea to ask for any old parts that are being replaced. If there was a chance that anything other that brakefluid was put into the system (especially any type of oils), you should be able to tell and it will render anything rubber in the system junk. Master cylinder seals, Caliper seals, Rubber brake lines, Proportioning valve seals. ect ect, if it's rubber its junk now.
I don't think there's a special process for ABS brake bleeding, I did my 98 Sierra the old fashion way, having someone pump the pedal and build line pressure, hold down on the pedal, then release the bleeder valve on the wheel furthest from the master cylinder while they push the pedal to floor. Do not let them lifth the pedal (allow the pedal to return) until the bleeder is closed. Repeat this until there is no air bubbles coming out with the fluid, then move to the next furthest wheel from the master cylinder, working you way closer to the master cylinder. Then repeat the whole process just to be sure.
On my Sierra It's not that the ABS functions bad, it works properly. I'm just old fashion and like to control my brakes myself.
By the way I've been driving my 2000 Blazer with both the ABS and the Brake lights lit sense day one(for me thats been the past few months). The ABS won't function but the brakes work like a perfect set of old school brakes.

 

Ok, I will look into getting the brakes rebled. Seems to be cheap insurance at this point anyway. I usually ask for the parts if I am at a place I don't trust 100% or if I go to a place for the 1st time (and I travel alot). The other work (calipers/rotors/pads) was done only 3 miles from where I live and the owner is very honest so I didn't ask for the parts back in that case since there was no reason to since I knew what the problem was already (caliper stuck). The reason why I didn't get the master cylinder back when I had the truck towed in NJ was because my mother was standing there when I asked to inspect the part and she said "No, we are not keeping junk car parts!". I got into an argument with her after the brakes failed the 2nd time because I wanted to get that master cylinder inspected and tested and if it was good, I would have tried to take the shop in NJ to court for a refund since it was an improper repair that did not fix the problem and almost caused an accident. Now I know not to allow her to have a say in the matter if anything like this ever happens again and she is feeling really stupid now that she stopped me from keeping the part.
I no longer think there is anything other than brake fluid in the brake system since I would have no brakes and leaks everywhere now that you mentioned what happens when oil gets into it and I would have had a fat bill by now for the replacement of nearly all the parts anyway. Gallons of brake fluid have been flushed through it since the initial failure by now anyway so any traces of anything would be gone by now anyway.

By the way, as far as I have read online, if you have both the BRAKE and ABS lights on, that usually means that the ABS module is bad, unless you have an ABS code and a stuck pressure switch (the switch issue happened on this truck 2 weeks ago- just after the first caliper, rotor and pads were replaced. Another shop (this was on a Saturday and it was the only thing open at the time) just pressed the brake pedal hard and it went out). Unfortunately, ModuleMasters can only fix the modules that are used in the S-10 trucks if the only problem is the motor running continuously. They can completely fix the ones that are used in the fullsize trucks. I actually looked it up today in case any future brake problems involve the module.

 

Hope you've got it all figured out by now. Just keep in mind that if a system gets contaminated with oil, you can't flush it out. Once the oil comes in contact with anything rubber it starts to swell. The seals swell out of shape and leak, the lines swell shut on themselves causing a problem similar to a stuck caliper or wheel cylinder. I'm not saying your system got contaminated just giving a heads-up.
Good luck.

 

Thanks for the tip about the oil. I am not really convinced the system is contaminated now because I have driven this truck over the past 2 weeks since the first repairs over 1000 miles testing the brakes often and I haven't had a single brake failure or leak. I originally thought it was possible because the shop in NJ where I had the master cylinder replaced treated us poorly, did the improper repairs and their attitudes gave me the idea that they seem to be the type who would do that (especially how they treated us and gave us a huge attitude after the brakes failed the 2nd time- AFTER they replaced the master cylinder). I am sure that the local shop near my house in NY state (that I trust 100%) that did the calipers, rotors and pads would have noticed something wrong because they also checked the system since I also mentioned the warning light incident and they promised to look at it. They found no other issues and I am sure they would have noticed and mentioned if there were any signs of sabotage. I will be sure to post the name of the shop in NJ at a later date (with a link to this thread) where the truck was towed to on both incidents because I feel it is worth mentioning because if any Blazer owner here has the misfortune of breaking down near any of their locations, they already know to seriously consider not to allow their truck to be towed there. Thanks again for the advice.

 

Ok, here is my dumb question about this whole thing. Was there any way of preventing all this and the related repair bills? I had the brake fluid flushed last year and I had new brakes and rotors all around last year. Was there something I overlooked or neglected that caused the calipers to get stuck? If the master cylinder was actually bad (unlikely), was there any preventing that?

P.S. As soon as I find a place in this small town that specializes in brakes that can just bleed the system (or the ABS if there is air in that), I am getting the system rebled again. I don't want to take any chances. I NEVER want this to happen again if I can prevent it. These incidents almost caused a serious accident. At least I was able to ask the fine people on Blazerforum for assistance on this brake problem and making the repairs alot easier to understand and prevent a future occurrence than having to start a much different thread with photos of a wrecked truck and asking about finding a new Blazer or Jimmy.

 

My daughter's 2000 Blazer had new brakes and rotors all the way rnd at 125000 miles, by 130000 miles the right rear pads and rotor were gone, there was no sign of sticking rotor but what else could it be. Had it serviced in AZ, they had never worked on brake system with rust before so it took them all day to get stuff apart. Vehicle spent it's life previous in snow and salt.

 

Sounds like possibly a malfunctioning proportioning valve. At any rate, I agree that after a major falure like this, its best to replace all the components involved. And does your technician have to equipment to properly bleed the HCU? If air is left in the ABS module, it can give weird feedback. An old trick is to take the truck down a gravel road and stomp on the brakes, activating the ABS, therefore forcing any air in it down the lines to the calipers. Bleed the brakes once again, and re-check. Repeat until you reach the desired feedback.

EDIT: Dont bother doing a brake job if youre not going to service the caliper. Always grease the slide bolts and any other moving parts to avoid future issues. It will save you a ton of time and money in the long run.

 

Ok, I had the brakes rebled and they found a small amount of air in the system at the rear right caliper. However, I found it weird that they only seemed to charge me for 1/2 a pint of brake fluid. The problem with the intermittent soft pedal seems to have been reduced, but not completely erased. The car stops fine with no pedal going to the floor or anything like that. The pedal only goes down to about 1/2" above where the gas pedal is at idle. I also noticed that the brake pedal has alot of side to side play as if it isn't attached correctly. Is it also possible the bolts attaching the pedal are loose?