Typerod

Hi all, so yesterday I was driving home from an errand and got to the stoplight turning into my neighborhood. Just as soon as the car was about to come to a complete stop, I feel and hear a noise from the front brakes, and the noise is hard to describe, just like a quick grunt. It didn't feel right at all, and when it was time for me to go, I left off the brake pedal and the car didn't want to move, I gave it some gas and you can definitely feel it dragging.

So I get home, got out my IR thermometer and took readings from the rotors, back of the brake pads, and the caliper, on the front brakes on both sides. Rotor temps and back or brake pad temps were ~60 degrees F higher than the right side. Front left rotor was about ~260 degrees the front right rotor was ~200 degrees. I jacked up the front end and took off the front wheels. I had to wait a bit b/c the front left components were just too hot to touch for more than a few seconds. I didn't see any obvious damage to any components. Once I got the wheel off on the left side, I was able to turn the rotor a bit, so then I just wanted to test it, started the car and pressed and let go of the brakes, and the front left rotor wouldn't move, of course I'm trying to turn it by hand, but you can def. tell something wasn't right.

So I took off the left caliper and then the rotor turned freely as it should. I removed the brake pads for inspection and see some slight glazing. The left rotor is blue'd and glazed as well. The front left brake pads were also a bit thinner than the front right brake pads. I did a complete rotor and brake pad change on all fours about 2 years ago, there is only about ~31K miles on these pads and rotors. Those are just some indications that the front left caliper, or flex brake line, or maybe the brake master cylinder is to blame? am I correct in my troubleshooting here?

I was able to compress the pistons in with no unusual issues. Front left and front right caliper pins were well lubes and free moving. I flush the brake fluid on about a ~30k to 50k mile interval. The brake flush was done just May 2015.

The right side rotor and pads were not glazed, the right side brake pad were significantly thicker compared to the left side pads, and I was able to turn the rotor more freely than the left side. So I put everything back together, took a test drive about 10 miles, and no repeat symptoms occurred. No short grunt when coming to a stop, no dragging felt at all. But I did take a temp reading again once I got back from the test drive, and the front left rotor was ~306 degrees F vs. the front right which was about ~250 degrees F. My thinking is the front brake temps should be relatively about the same temp if there were no issues. So a 50+ degree swing makes me suspect of the left side.

Either way, I have the amateur skill to replace simple bolt on parts, but since I don't have a brake fluid bleeder, or good brake trouble shooting skills, I have scheduled an appt. today at the dealer, the dealer which I had a bad experience a few months ago with my alignment, as some of you who frequent the Tahoe section may have read, where I swore to not give them my business anymore. I really don't have a choice, I don't feel comfortable letting my wife drive the car with this intermittent problem, and they are the closest dealer to me (only ~5 miles away).

I recall some few years ago, I noticed this dragging on the front left side, but nothing indicated to me that it might be a brake issue, and I chalked it up to a bad wheel bearing, and had the dealer replace it on my request. And sad to say, it was a waste of time and money, b/c the issue was still there. When I would jack up the front end to spin the wheels as a test sometimes it would spin freely other times it wouldn't. So now that the symptoms are showing the true root cause and more problematic, hopefully the dealer will do right by me today. LOL!

Any input is appreciated! I love learning about cars and have learned quite a bit from the good folks who frequent this site, so I tip my hat to you all!

P.S. here are some pics of the left side rotor and pads. I forgot to mention, the brake pedal feels firm mostly but at time it tends to feel a tiny bit mushy, I did notice right after I had my rear diff rebuilt, but didn't think much of it.

Typerod

I mentioned I got a brake fluid flush last year. Here is a pic of the fluid in the reservoir, its hard for me to tell if its super dirty or its just a dark color b/c the fluid is gathered in the reservoir. Also noticed there is no o-ring in the brake fluid cap, wish there was one.

73shark

Sometimes the inner lining of the brake hose comes loose and acts as a check valve, not allowing the pistons retract. Had that happen on my 87 IROC once. Same symptoms as you described.

Typerod

thanks for the reply Shark! im at the dealer now, and im hoping the tech does his due dilligence and trouble shoot thoroughly. even if they dont suggest it, i just may have them change both front flex brake hoses, just to avoid that issue in the future. seems like that hose issue is a really common problem.

Typerod

estimate was 1200 dollars, but they didnt hv all the parts and couldnt do it today. so i decided not to do it just yet, if they had the parts and would do it today i wouldve went for it

tech2

what parts did they call?

Typerod

Both front calipers (~$252/caliper + 2.5 hrs labor @ ~$118/hr) as well as both flex brake lines (~$53 per line, no labor charge), a new set of brake pads (~$86, no labor charge) for the left front side (current set has enough meat on them, as you can see from the pics up above) and they had to do the brake flush (~$32.00 for fluid and 1 hr labor @ ~$118/hr)

Mad Dawg

If you're handy with basic tools, you can do the work for SIGNIFICANTLY less!!!!! Those part prices the stealership is quoting is having you bent over a log and squealing like a pig!!! A quick check at RockAuto.com shows new OEM calipers are approx. $124 each (L/R different prices) and remanufactured OEM calipers at around $40- $60 depending on coating. New OEM brake lines are less than $10 each and the front pads again going with OEM, have the widest price discrepancy ranging from $25 to $100 depending on application. Lastly 3.5 total labor hours!?!?!?!?!?!?!? Any competent mechanic can do this whole job in about an hour. Do this work yourself, find a friend who can and offer a him a good bottle of bourbon in exchange and save yourself more than $750, or find a trustworthy indy mechanic.

tech2

the Mitchell book time for each job is:
1.8hrs- both front calipers includes abs bleed
1.1 hrs- 2 flex hoses includes abs bleed
1.0 hrs- complete fluid flush is not listed but 1 hr is what most shops charge.

Typerod

I'm not a seasoned tech (just a DIY'er), but I can do basic bolt on repairs. I don't have a bleeder tool and have never done a brake line bleed. So I don't feel entirely comfortable doing the bleed, but since I can probably do the caliper change and flex line change, but not the bleed, then theres no sense in me trying and having my car dead in my driveway, lol. I got the parts much cheaper from summit racing and ebay, and gmpartsdirect.com, all OEM GM. Total cost of parts is about $275. By the way if anyone was interested i ordered a superceeded part for both front calipers and they were a fraction of the price of the original part numbers, but i cancelled the order, bc of my fear of cheap parts even though there were GM parts.

So does this mean, a typical brake fluid flush or brake fluid bleed wont cut it? What is involved in an ABS bleed? Thanks!