Caliper locked - what's the fix?
Thread Starter
Running Guns & Moonshine
Joined: Aug 2001
Posts: 12,672
Likes: 7,306
From: CT
Caliper locked - what's the fix?
I finished my brakes on the daily today and bled the fronts. Possibly the driver front caliper is locked as I'm partway out my neighborhood. Before leaving, I did notice the brake pedal was soft / low, but I thought a fewight stops and vacuum would solve it. When I walk around the car, the brake lights are on permanent.
I did not allow air in the system. I did do the job one man with speed bleeders.
Could I have depressed the brake pedal too hard or too far?
What's the fix for this? Anything I can do roadside with tools from down the street?
I did not allow air in the system. I did do the job one man with speed bleeders.
Could I have depressed the brake pedal too hard or too far?
What's the fix for this? Anything I can do roadside with tools from down the street?
Racer
Joined: Jun 2011
Posts: 444
Likes: 91
From: Delaware
See if you can get the piston to collapse with a flathead screw driver if possible if not then use a c-clamp. Usually a locked caliper is gonna need a rebuild or a new caliper. I have never rebuilt one; I just replace the caliper
Thread Starter
Running Guns & Moonshine
Joined: Aug 2001
Posts: 12,672
Likes: 7,306
From: CT
I think instead that it is the plunger in the master. I had done the physical brake job last week and only bled them today. The calipers have been fine and new pads are bedded.
I think on the final wheel, driver front, I depressed the pedal too far or hard. It felt different, dropped down and never really came back up. I tried pulling it up with my feet just now, still stuck by the side of the road, and now it is firm as a rock. Brake light is still full time ON.
I think on the final wheel, driver front, I depressed the pedal too far or hard. It felt different, dropped down and never really came back up. I tried pulling it up with my feet just now, still stuck by the side of the road, and now it is firm as a rock. Brake light is still full time ON.
Thread Starter
Running Guns & Moonshine
Joined: Aug 2001
Posts: 12,672
Likes: 7,306
From: CT
I got it home for now by opening the driver front bleeder. That unlocked the brakes. But the pedal itself is down by the floor and soft now. And the brake lights were full time on.
I pulled the negative cable and will go back at it in the morning. Did I bust something in the master cylinder?
I pulled the negative cable and will go back at it in the morning. Did I bust something in the master cylinder?
Melting Slicks
Joined: Jun 2013
Posts: 3,473
Likes: 691
From: West Virginia
Thread Starter
Running Guns & Moonshine
Joined: Aug 2001
Posts: 12,672
Likes: 7,306
From: CT
The brake released.
I got the car back to the garage.
But the pedal remains soft while also keeping the brake lights on.
I had done a vacuum setup at each corner with the hose empty of air and submerged in fluid before cracking each bleeder so while the symptom suggests air in the line, there shouldn't have been a way for that to happen.
My thought for today is to buy a few more hoses and try the Tech2 to be sure the lines are clean.
However, that still does not explain to me quite how the pedal has been.
I got the car back to the garage.
But the pedal remains soft while also keeping the brake lights on.
I had done a vacuum setup at each corner with the hose empty of air and submerged in fluid before cracking each bleeder so while the symptom suggests air in the line, there shouldn't have been a way for that to happen.
My thought for today is to buy a few more hoses and try the Tech2 to be sure the lines are clean.
However, that still does not explain to me quite how the pedal has been.
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Melting Slicks
Joined: Apr 2019
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From: Clark, NJ
Check the brake pedal up under the dash and see why it's not fully releasing. I saw this happen once where the brake light switch was pushed forward and cocked, causing the brake lights on constantly and the brakes not releasing pressure like you describe.
Le Mans Master
Joined: Jun 2007
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From: BEST Corn-Nation
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I haven't worked on a brake issue since they started putting ABS on everything. I think you're thinking with the tech2 might show something. It does sound like it might be a master cylinder to me but I haven't had any issues with mine yet to say anything else.
Drifting
Joined: Mar 2018
Posts: 1,365
Likes: 414
From: New Jersey
It sounds like the pressure differential switch on the master cylinder has been activated. That will turn the brake light in the dashboad on. Read the DIC codes there is a DTC code 1247 that comes up if that's what's happening. You probably have a failed master cylinder.
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check the brake switch on the pedal, if the pedal is low enough it's possible that it is disengaging the switch thus making the brake lights stay on... you might just need to bleed them over again and when you are done fully pump the brakes before you drive the car
Thread Starter
Running Guns & Moonshine
Joined: Aug 2001
Posts: 12,672
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From: CT
I just got to the shop with my Tech 2 and some extra lengths of tubing so I can do all four at once. After I get the smoker going I'll get the car in the air. I need to have the turkey medallions waiting for tonight.
Melting Slicks
Joined: Nov 2014
Posts: 3,399
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From: Havre de Grace Maryland
Wow. Reading all the info from various persons on this issue makes me more comfortable about NOT doing anything on the C5 mechanistically and taking it to my go to Vette mechanic that is #1. I long for the days of carburetors and simple mechanical items like disc breaks on the corvettes that I could repair.
Thread Starter
Running Guns & Moonshine
Joined: Aug 2001
Posts: 12,672
Likes: 7,306
From: CT
It must have been air in the line. Or something I didn't figure out. When I got to the car today I had to remove the dust cover above the footwe because the pedal had pushed so far up and so firmly. Whatever was wrong was already resolved somehow. Yet no leaks anywhere. I tested it in th driveway and then a ride outside the neighborhood with multiple stops. It worked fine. Go figure. But I still popped it in the air and did the Tech 2 bleed for peace of mind. It was an easy process, but I don't like getting all four off th ground unless it's on a scissor jack or two post lift typically.
Melting Slicks
Joined: Sep 2011
Posts: 2,258
Likes: 544
From: Appleton WI
The one thing that comes to mind is you boiled your fluid and that is why the pedal stayed on the floor. Once it cooled, the pedal returned to normal operation.
How does the rotor look on the side that seized up? Blue tint would verify you overheated that rotor.
How does the rotor look on the side that seized up? Blue tint would verify you overheated that rotor.