Brake caliper pressure
08-12-2016, 08:37 AM
#1
Instructor
Thread Starter
Brake caliper pressure
Hey guys I have a passenger side front brake caliper that seems to hold too much pressure on the rotor which appears to "heat up" & cause the interior brake pedal to become very hard. Also way too much brake dust accrues on the wheel rim . Any ideas as to correcting or to diagnosing for sure that I have this caliper issue.
I really don't want to spend the $100 to replace w/o validating.
I really don't want to spend the $100 to replace w/o validating.
08-12-2016, 11:13 AM
#2
Tech Contributor
Member Since: Dec 1999
Location: Anthony TX
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CI 6,7,8,9,11 Vet
St. Jude Donor '08
YES! That caliper SLIDES on two sliding pins. Sounds like the pins are seized or improperly lubricated.
Take the entire caliper off of the bracket. The pins have black boots that seal them to the caliper. Pop off the boots and pull out the pins.
They should pull out and push back in very smoothly. If they are dry/rusted and need to be cleaned and regreased, You MUST use the special caliper pin grease! If the boot is damaged, you will have to purchase a caliper rebuild kit to get new rubber boots.
NEXT
The brake pads slide on a spline on the caliper. If the brake pad bracket and the caliper is rusted/corroded, the pad cant slide and release. Clean it and use a very small coating of antiseize where the pad slides on the caliper.
The caliper SHOULD have ANTI RATTLE hardware installed and that all needs to be in good shape.
Take the entire caliper off of the bracket. The pins have black boots that seal them to the caliper. Pop off the boots and pull out the pins.
They should pull out and push back in very smoothly. If they are dry/rusted and need to be cleaned and regreased, You MUST use the special caliper pin grease! If the boot is damaged, you will have to purchase a caliper rebuild kit to get new rubber boots.
NEXT
The brake pads slide on a spline on the caliper. If the brake pad bracket and the caliper is rusted/corroded, the pad cant slide and release. Clean it and use a very small coating of antiseize where the pad slides on the caliper.
The caliper SHOULD have ANTI RATTLE hardware installed and that all needs to be in good shape.
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baileysade (08-12-2016)
08-12-2016, 06:54 PM
#3
Drifting
If the hoses are original, they may block fluid from returning to MC after taking foot off the brake and causing caliper to drag. I saw this once. Can't explain why hose would act like a check valve but it happens.
Jack up the wheel, push brake pedal for all you are worth, get out and try to turn the wheel. If it drags the brake is not releasing for some reason.
Jack up the wheel, push brake pedal for all you are worth, get out and try to turn the wheel. If it drags the brake is not releasing for some reason.
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baileysade (08-12-2016)
08-12-2016, 09:28 PM
#4
Instructor
Thread Starter
Great advice !! Will investigate first thing in the A M
YES! That caliper SLIDES on two sliding pins. Sounds like the pins are seized or improperly lubricated.
Take the entire caliper off of the bracket. The pins have black boots that seal them to the caliper. Pop off the boots and pull out the pins.
They should pull out and push back in very smoothly. If they are dry/rusted and need to be cleaned and regreased, You MUST use the special caliper pin grease! If the boot is damaged, you will have to purchase a caliper rebuild kit to get new rubber boots.
NEXT
The brake pads slide on a spline on the caliper. If the brake pad bracket and the caliper is rusted/corroded, the pad cant slide and release. Clean it and use a very small coating of antiseize where the pad slides on the caliper.
The caliper SHOULD have ANTI RATTLE hardware installed and that all needs to be in good shape.
Take the entire caliper off of the bracket. The pins have black boots that seal them to the caliper. Pop off the boots and pull out the pins.
They should pull out and push back in very smoothly. If they are dry/rusted and need to be cleaned and regreased, You MUST use the special caliper pin grease! If the boot is damaged, you will have to purchase a caliper rebuild kit to get new rubber boots.
NEXT
The brake pads slide on a spline on the caliper. If the brake pad bracket and the caliper is rusted/corroded, the pad cant slide and release. Clean it and use a very small coating of antiseize where the pad slides on the caliper.
The caliper SHOULD have ANTI RATTLE hardware installed and that all needs to be in good shape.
08-12-2016, 09:30 PM
#5
Instructor
Thread Starter
I be live the hoses are original & have heard/ read that they can cause an obstruction . Will check it out 
If the hoses are original, they may block fluid from returning to MC after taking foot off the brake and causing caliper to drag. I saw this once. Can't explain why hose would act like a check valve but it happens.
Jack up the wheel, push brake pedal for all you are worth, get out and try to turn the wheel. If it drags the brake is not releasing for some reason.
Jack up the wheel, push brake pedal for all you are worth, get out and try to turn the wheel. If it drags the brake is not releasing for some reason.
08-12-2016, 10:18 PM
#6
Team Owner
If the hoses are original, they may block fluid from returning to MC after taking foot off the brake and causing caliper to drag. I saw this once. Can't explain why hose would act like a check valve but it happens.
Jack up the wheel, push brake pedal for all you are worth, get out and try to turn the wheel. If it drags the brake is not releasing for some reason.
Jack up the wheel, push brake pedal for all you are worth, get out and try to turn the wheel. If it drags the brake is not releasing for some reason.
Had the exact same thing happen on a Pontiac I had years ago. 
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baileysade (08-13-2016)
08-13-2016, 08:21 AM
#7
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Location: Anthony TX
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CI 6,7,8,9,11 Vet
St. Jude Donor '08
ANYTHING that prevents the caliper from releasing will cause it to DRAG. You just have to DIG IN and start investigating.
I pry the caliper so that it compresses the pistons into the caliper. That allows me to actually slide the caliper on the sliding pins while its still mounted. It also allows me to see if the pistons are free to move and the fluid can return to the system.
NOTE! If you are doing brake work and intend on replacing the pads, OPEN the bleeders and then compress the pistons.. That way the nasty fluid is not being forced back into the system.
I pry the caliper so that it compresses the pistons into the caliper. That allows me to actually slide the caliper on the sliding pins while its still mounted. It also allows me to see if the pistons are free to move and the fluid can return to the system.
NOTE! If you are doing brake work and intend on replacing the pads, OPEN the bleeders and then compress the pistons.. That way the nasty fluid is not being forced back into the system.
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baileysade (08-13-2016)
08-13-2016, 09:42 AM
#8
Instructor
Thread Starter
Thanks Bill, will take a look at QUOTE=Bill Curlee;1592838261]ANYTHING that prevents the caliper from releasing will cause it to DRAG. You just have to DIG IN and start investigating.
I pry the caliper so that it compresses the pistons into the caliper. That allows me to actually slide the caliper on the sliding pins while its still mounted. It also allows me to see if the pistons are free to move and the fluid can return to the system.
NOTE! If you are doing brake work and intend on replacing the pads, OPEN the bleeders and then compress the pistons.. That way the nasty fluid is not being forced back into the system.[/QUOTE]
QUOTE=Bill Curlee;1592838261]ANYTHING that prevents the caliper from releasing will cause it to DRAG. You just have to DIG IN and start investigating.I pry the caliper so that it compresses the pistons into the caliper. That allows me to actually slide the caliper on the sliding pins while its still mounted. It also allows me to see if the pistons are free to move and the fluid can return to the system.
NOTE! If you are doing brake work and intend on replacing the pads, OPEN the bleeders and then compress the pistons.. That way the nasty fluid is not being forced back into the system.[/QUOTE]