When I saw this thread title, a light bulb went off. I chased this same code for a while. I first through MAF, which I cleaned, and the light went off. It would come on at weird times though. Very sporadic. I was thinking the O2 sensor as well, and had it on my list to do. When I was taking advantage of a cheap spark plug change out special at a local shop, they ran the code and next thing I know, the guy has the Blazer on a rack and is dumping coolant. I'm like, WTF? He says that it's the heater sensor, and a $9 part, so he's going ahead and changing it for me. Only charged me for the part.

Sure enough, light has been out since, no codes. There are times I guess when I'm just going to admit I have no clue what I'm doing. I'm just glad their are an insane number of S10s running around my area, as all the shops seem extremely well versed on what the need.

 

NO! DO NOT use a c-clamp EVER! Throw that caliper piston retractor in the junk box with the pickle fork.

Use one of the old pads against the piston fill the caliper bracket with odds and ends and use a large screwdriver to pry against the pad and push piston back. Pistons should retract slowly but easily with no 'bumps'. If they dont, you either need to rebuild or replace the caliper. If I'm replacing rotor I just retract before I pull the caliper off.
WHY?
You have an old car and you cant be sure WHAT is isn the brake system.
Because with a C Clamp you wont know if the piston and bore are contaminated and hanging up. This possibly leads to wasting your pads and rotor quick time.

The ONLY special piston retract tool worth crap is for rear calipers with screw in park brake adjustment.
BTW, you do ONE side complete job at a time.

 

What??? That's a new one. Been using c-clamps for brake jobs for over 25 years. Haven't had a problem yet. Foreign jobs need that retractor tool, but no GM I've ever owned required anything but a c-clamp.

If your brakes work at all, they're not hung up. If they're that old, just replace the caliper.

In all my years of doing 30 year old to modern motorcycles, cars, & trucks I've never heard of anyone damaging a caliper by pushing the piston back with a clamp.

 

Smitty.. no where did I say a c-clamp damaged the caliper.

I said the only 'special retract tool' needed is for rear calipers with screw-in for parking brake adjustment. Didnt SAY GM needed em. I know many Fords do.

My point is that you get a much better feel about contamination in the bore if you pry it back by hand. I did use clamp, till I had to do one over again and replace caliper. Which I probably would have done in the first place if I'd pushed it back by hand.

I dont know how to answer that without expletives...

 

Only time I've seen a clamp not work was on a Ford I had, that needed some sort of weird block with pins on it, and you had to rotate the piston back into the caliper.

Levering the pistons in via a screwdriver or clamp is the same. I can see that it would be easier to _feel_ if there was some kind of rough spot in the travel, but it shouldn't damage anything either way.

 

Go with te C-clamp. Rotate slowly. Don't crank the piston in fast.

I understand where PETTYFOG is coming from. If there's Crap (rust) in the caliper and you push all that back into the ABS and Master, you may have an issue.
I'm 50 years old, I have 8 cars and I've been working on them since I was 16 (Still have one of my original cars). Never had a problem with C'clamp of ratcheting pliers to retract the piston..
In fact I usually pusj in all the calipers, suck the fluid out of the MAster cylinder and add fresh. It's a half-assed flush but it seems to keep me trouble free.
SHABLAZE: Disc Brake replacement is quite simple. Have a handy neighbor do them with you and your son assisting. You will easily understand what does what and from then on, you can save a bundle doing them yourself in the future.

 

I use a welding clamp, Vise Grip handle style, big opening that closes all the way.



It's hand power, and you have to adjust the clamp several times to get it all the way in. I did feel resistance once, with a little jumping as it goes in. I knew that was different, so I took the calipers apart and there was a tiny rust spot on the cylinder. Dremel with a PLASTIC polishing wheel took off the rust with no marks on the metal. Did the other side too (rears are drums), and it had a rust spot, but wasn't giving resistance. No parts required to get it fixed.

I always pull/push a significant amount of fluid through. Maybe not a full flush, but see some sign of new fluid coming out. After rebuilding calipers, I made sure new clean fluid made it all the way through the system.

 

I got someone to show him how to do the front brake pads and we took the rotors to o'reilly to have them turned. I don't know exactly what the used or how they did it but no clamp was used. When it comes time to do it again, I hope we have our own tools.
What do we do with the back? Are there pads? How do we know if they need to be changed?

 

Do some of these newer Blazers have a screw adjuster like ATV's do for rear parking brakes? I've only seen the little drum & shoe setup with a normal caliper back there on the newer ones I've worked on.

But yeah that was my point - if the piston is that rusty, just replace the damn thing. It's what ... $20? We used to rebuild them back in the day - easy as pie with compressed air ... but with all this chinese crap out there today it saves time just buying a new one. Half the pistons are plastic today anyway, so the o-rings inside will wear out & cause the piston to **** sideways a bit - usually just enough to smoke your pads & warp the rotor.

No need to feel anything - if it needs replacing, then that's what you do. But do what you want - it's a free country. To each his own.

Shablaze - yes there are pads - same principle as the fronts. When the friction material gets thin, toss them & replace with new of your choice. Usually they'll have a metal tab on the anti-rattle shim that will contact the rotor & make all kinds of noise when they get thin, but don't count on that. Seen lots of them bent far enough so that the pads were down to the rivets without that tab even coming close to the rotor. Especially ones installed by Midas or the like.

 

Hoss - no offense but I've been doing brakes longer than a lot of people on this forum have been breathing. There's a good chance my c-clamp collection is older than you are... and I bought it new. No special "caliper piston retractor" has graced my pile-o-tools; just woodworking c-clamps.

Yep - need to take care when redoing brakes but you can generally use a good c-clamp to feel the piston's 'fit' to the caliper & feel the sediment ridge if a caliper is frozen.

Pickle-fork? Got one, know how it works, have vehicles I've used it on. What's that have to do with brakes?

I don't think the op was talking about the e-brake.

Edit: See that some other old farts chimed in as well. We lost something when the digital age pushed aside setting points with a matchbook.

shablaze: Glad ya got the fronts fixed!