Calipers keep locking one after another
Thread Starter
2nd Gear
Joined: Oct 2015
Posts: 2
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From: Ravenna Ohio
Calipers keep locking one after another
I have a 1975 Stingray. I upgraded to Stainless Steel Brake lines and since that upgrade I've had three calipers lock up one after the other.
First it was the front drivers side, then the front passenger, and now the rear driver's side. The first two times I had my Corvette transported to a mechanic on a flat bed and both times (two different mechanics) said that they couldn't find a cause but got the caliper loose and then the next caliper would lock.
Have any of you heard of this happening, or have any guesses as to the cause?
Thanks, Greg
First it was the front drivers side, then the front passenger, and now the rear driver's side. The first two times I had my Corvette transported to a mechanic on a flat bed and both times (two different mechanics) said that they couldn't find a cause but got the caliper loose and then the next caliper would lock.
Have any of you heard of this happening, or have any guesses as to the cause?
Thanks, Greg
Safety Car
Joined: Sep 2005
Posts: 4,226
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From: Orange County Ca
I've heard of this with collapsed old rubber lines at the calipers, which would allow high pressure fluid to go to the calipers, but would collapse and not let the lower pressure fluid return.
If this only happened after you changed your flex lines, I would think that they are the problem.
If this only happened after you changed your flex lines, I would think that they are the problem.
Drifting
Joined: May 2012
Posts: 1,353
Likes: 44
From: Calgary Alberta
Rubber hoses I would say, as above. A test is to drive it a little until you start to get a little lock up at a wheel, then go home and park it (obviously don't go too far from home). Let it sit for a few hours. The hoses will often allow fluid to return over time if they are collapsing, so if the lock up condition is lessened or gone after some time, it's the hoses. They can look fine from the outside but be gone inside.
Easy fix if it comes to changing them.
Easy fix if it comes to changing them.
Team Owner
Joined: Jan 2006
Posts: 37,637
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From: Crossville TN
Old rubber flex lines is also a safety hazard; partially applied calipers heat very quickly and can eventually start a tire fire...and from there,
Not good! Change those flex lines, if they're old.
Not good! Change those flex lines, if they're old.
2026 Loser of the Year
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From: New Or-leens Loo-z-anna
It's rare that this happens....but...........
if you have power brakes, the rod between the brake booster and the master cylinder could be out of adjustment/slightly too long----causing the calipers to have just enough pressure to rub against the rotors more than normal----then they would "grab"...........
also.......the brake pedal itself might not be returning completely for some reason causing the booster to apply slight pressure to the calipers which would cause the caliper that got the hottest to grab.
if you have power brakes, the rod between the brake booster and the master cylinder could be out of adjustment/slightly too long----causing the calipers to have just enough pressure to rub against the rotors more than normal----then they would "grab"...........
also.......the brake pedal itself might not be returning completely for some reason causing the booster to apply slight pressure to the calipers which would cause the caliper that got the hottest to grab.
Race Director
Joined: May 2006
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how about some more info on those "new" stainless steel brake lines? do you mean the flexible hoses that connect to the calipers in the front and to the trailing arms in the rear or something else? if they are the flexible ones where did you buy them?
Team Owner
Joined: Jan 2006
Posts: 37,637
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From: Crossville TN
ALL of the flexible brake lines are made of synthetic rubber. Some of them have SS braided jackets on the outside for damage protection and for appearance. And, with time ALL of them will fail internally. It is bloomin' amazing that it has taken 40 years or more for some of them to fail. Most have been replaced already...not because they have failed, but because the entire brake line system has been replaced and they got thrown out at the same time. In fact, that's a GOOD thing--preventive maintenance.
It's not a rare failure...it's just infrequent by human time standards. But, the replacement parts will likely survive a much shorter time than the originals, as many of the synthetic rubber materials used to create them are of poorer quality (less expensive). The problem is that the damage is on the INSIDE and is not visible when inspected.
It's not a rare failure...it's just infrequent by human time standards. But, the replacement parts will likely survive a much shorter time than the originals, as many of the synthetic rubber materials used to create them are of poorer quality (less expensive). The problem is that the damage is on the INSIDE and is not visible when inspected.
Le Mans Master
Joined: Sep 2003
Posts: 8,812
Likes: 2,029
From: eastern NC
Wilwood, Earls, Stoptech, Russell, and a myriad of others make them. Just be sure to look for the DOT sticker to ensure that they are legal for street use.
Good luck... GUSTO
Last edited by GUSTO14; Oct 15, 2015 at 07:34 AM.
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Joined: Sep 2012
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From: Palm Harbor, Florida
It's rare that this happens....but...........
if you have power brakes, the rod between the brake booster and the master cylinder could be out of adjustment/slightly too long----causing the calipers to have just enough pressure to rub against the rotors more than normal----then they would "grab"...........
also.......the brake pedal itself might not be returning completely for some reason causing the booster to apply slight pressure to the calipers which would cause the caliper that got the hottest to grab.
if you have power brakes, the rod between the brake booster and the master cylinder could be out of adjustment/slightly too long----causing the calipers to have just enough pressure to rub against the rotors more than normal----then they would "grab"...........
also.......the brake pedal itself might not be returning completely for some reason causing the booster to apply slight pressure to the calipers which would cause the caliper that got the hottest to grab.
This is a tough one...
Team Owner
Joined: Jan 2006
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From: Crossville TN
The pedal will return, as there is no restriction from it doing so. If you haven't experienced it, you won't understand it. But, if YOUR brake caliper hangs up and the rim/tire gets VERY hot, you will then understand.
This is an inevitable problem. Flex lines will [and DO] fail. Many times it is not diagnosed properly and folks just change everything out. That solves the problem, but they're never really sure what was going on.
But, when someone changes out all the brake lines [and doesn't change out the rubber flex lines], then the calipers hang up...what's left??
I would ask that the folks who already intend to change out all brake lines or just the rubber ones, do so, and then cut through a couple of the flex lines. Then, they can look into the small passage hole and see what's there...then dig into the surface material at that passage to evaluate the integrity of the rubber material passing the brake fluid. After doing this, they could report back to the CF so that folks can learn what the inside of a 40 year-old piece of rubber looks like after 'working' for that long with pressurized brake fluid. It will then become clear to most folks that changing out these rubber lines is very important if they buy a C3 and it still has the original lines on it.
This is an inevitable problem. Flex lines will [and DO] fail. Many times it is not diagnosed properly and folks just change everything out. That solves the problem, but they're never really sure what was going on.
But, when someone changes out all the brake lines [and doesn't change out the rubber flex lines], then the calipers hang up...what's left??
I would ask that the folks who already intend to change out all brake lines or just the rubber ones, do so, and then cut through a couple of the flex lines. Then, they can look into the small passage hole and see what's there...then dig into the surface material at that passage to evaluate the integrity of the rubber material passing the brake fluid. After doing this, they could report back to the CF so that folks can learn what the inside of a 40 year-old piece of rubber looks like after 'working' for that long with pressurized brake fluid. It will then become clear to most folks that changing out these rubber lines is very important if they buy a C3 and it still has the original lines on it.
Last edited by 7T1vette; Oct 15, 2015 at 12:38 AM.
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2026 Loser of the Year
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From: New Or-leens Loo-z-anna
This is all true, but keep in mind, he only changed part of the brake lines, nothing else. I think this is one of those cases where the problems are not related to the initial change. I am suspect of the rubber in the original lines that go directly into the calipers, but still, this is strange. Pretty easy to check that the pedal has returned all the way up. If so, replace the rubber lines going into each caliper, see what happens after that.
This is a tough one...
This is a tough one...
but.......like you guys said.....on my Vette project----after rebuilding the calipers and still having braking problems-----replacing the flexible lines solved the problems
Thread Starter
2nd Gear
Joined: Oct 2015
Posts: 2
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From: Ravenna Ohio
Thank you everyone who has posted. Sorry I haven't replied sooner, I've been really busy at work and home.
I will try replacing the flexible lines and move forward from there.
Take care, Greg
I will try replacing the flexible lines and move forward from there.
Take care, Greg
2026 Loser of the Year
Joined: Sep 2013
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From: New Or-leens Loo-z-anna
