Brake Pull to left at hard brake condition
04-23-2019, 06:08 PM
#1
Thread Starter
Join Date: Aug 2018
Location: OH
Posts: 10
Brake Pull to left at hard brake condition
Need some help on a '97 V6 Mustang brake problem that persists despite best efforts to resolve it:
The car pulls hard to left side when heavy pedal pressure is used, pulls less or not at all at low brake pedal pressure.
First attempt to resolve the problem was a simple four wheel brake system bleed.... no improvement. , First bled by pedal method, then used a vacuum system.
Next removed calipers, checked the pads and rotors (about 1/2 life left) and caliper motion, greased slide pins, reinstalled....no improvement.
Guessed that the calipers were not well matched, i.e. thought I had a bad caliper, probably on the right side since it was pulling left.
Bought a front brake kit including pads, rotors, and new rebuilt calipers, and also new brake hoses, installed.....still no change in the car braking... still pulls hard left at heavy brake pedal application. DAMN, this is a tough problem for a garage mechanic to solve!!
Jacked car front and rear, removed all four wheels, thoroughly inspected entire brake system. Reinstalled wheels, at first pedal application that stopped any wheel from turning, all four wheels were locked up. So statically, the brake system seems to work OK, but something is preventing the system from working under dynamic conditions when the pedal is applied firmly at road speed. Finally. rotated tires and test drove again. No change in behavior, still pulls to the left.
The only other thing I can think of is a front end alignment, but the car tracks dead straight going down the road. I have inspected the full length of the brake lines from the little manifold below the master cylinder, no "kinks" found. I have also inspected the front suspension and sway bar areas, and can't find anything that looks out of whack. I guess that I could also install new brake lines and remove and clean the little manifold that is below the master cylinder, maybe there is a restriction inside the brake lines that I cannot detect from a visual inspection.
Anybody got any next suggestions????
The car pulls hard to left side when heavy pedal pressure is used, pulls less or not at all at low brake pedal pressure.
First attempt to resolve the problem was a simple four wheel brake system bleed.... no improvement. , First bled by pedal method, then used a vacuum system.
Next removed calipers, checked the pads and rotors (about 1/2 life left) and caliper motion, greased slide pins, reinstalled....no improvement.
Guessed that the calipers were not well matched, i.e. thought I had a bad caliper, probably on the right side since it was pulling left.
Bought a front brake kit including pads, rotors, and new rebuilt calipers, and also new brake hoses, installed.....still no change in the car braking... still pulls hard left at heavy brake pedal application. DAMN, this is a tough problem for a garage mechanic to solve!!
Jacked car front and rear, removed all four wheels, thoroughly inspected entire brake system. Reinstalled wheels, at first pedal application that stopped any wheel from turning, all four wheels were locked up. So statically, the brake system seems to work OK, but something is preventing the system from working under dynamic conditions when the pedal is applied firmly at road speed. Finally. rotated tires and test drove again. No change in behavior, still pulls to the left.
The only other thing I can think of is a front end alignment, but the car tracks dead straight going down the road. I have inspected the full length of the brake lines from the little manifold below the master cylinder, no "kinks" found. I have also inspected the front suspension and sway bar areas, and can't find anything that looks out of whack. I guess that I could also install new brake lines and remove and clean the little manifold that is below the master cylinder, maybe there is a restriction inside the brake lines that I cannot detect from a visual inspection.
Anybody got any next suggestions????
04-24-2019, 04:21 PM
#5
Thread Starter
Join Date: Aug 2018
Location: OH
Posts: 10
Thanks, that is one of the next areas to investigate along with the brake line to the right front caliper. Do you know if the brake metering valve or "manifold" has a part number or other description, or do you know a source for a replacement? Or do I just take it apart and clean out the one I have with brake cleaner spray and compressed air?
04-25-2019, 01:13 PM
#6
Gentleman's Relish
Join Date: Feb 2005
Location: AZ
Posts: 13,090
Yes, try to clean out your old one first.
PN - F7ZC 2B091 BB
http://www.fordonlyparts.com/1997-19...f7zc-2b091-bb/.
Looks like they are out of production as even Rock Auto doesn't list it. Most that are found are aftermarket replacements that are adjustable.
PN - F7ZC 2B091 BB
http://www.fordonlyparts.com/1997-19...f7zc-2b091-bb/.
Looks like they are out of production as even Rock Auto doesn't list it. Most that are found are aftermarket replacements that are adjustable.
04-25-2019, 11:29 PM
#7
3rd Gear Member
Join Date: Aug 2015
Location: SE Michigan
Posts: 939
If you're going to take it apart for cleaning, consider rebuilding it with fresh seals: https://www.musclecarresearch.com/valve-kit-kh-E7ZC
07-26-2019, 12:51 PM
#9
Join Date: Jan 2014
Location: IN
Posts: 16
Need some help on a '97 V6 Mustang brake problem that persists despite best efforts to resolve it:
The car pulls hard to left side when heavy pedal pressure is used, pulls less or not at all at low brake pedal pressure.
First attempt to resolve the problem was a simple four wheel brake system bleed.... no improvement. , First bled by pedal method, then used a vacuum system.
Next removed calipers, checked the pads and rotors (about 1/2 life left) and caliper motion, greased slide pins, reinstalled....no improvement.
Guessed that the calipers were not well matched, i.e. thought I had a bad caliper, probably on the right side since it was pulling left.
Bought a front brake kit including pads, rotors, and new rebuilt calipers, and also new brake hoses, installed.....still no change in the car braking... still pulls hard left at heavy brake pedal application. DAMN, this is a tough problem for a garage mechanic to solve!!
Jacked car front and rear, removed all four wheels, thoroughly inspected entire brake system. Reinstalled wheels, at first pedal application that stopped any wheel from turning, all four wheels were locked up. So statically, the brake system seems to work OK, but something is preventing the system from working under dynamic conditions when the pedal is applied firmly at road speed. Finally. rotated tires and test drove again. No change in behavior, still pulls to the left.
The only other thing I can think of is a front end alignment, but the car tracks dead straight going down the road. I have inspected the full length of the brake lines from the little manifold below the master cylinder, no "kinks" found. I have also inspected the front suspension and sway bar areas, and can't find anything that looks out of whack. I guess that I could also install new brake lines and remove and clean the little manifold that is below the master cylinder, maybe there is a restriction inside the brake lines that I cannot detect from a visual inspection.
Anybody got any next suggestions????
The car pulls hard to left side when heavy pedal pressure is used, pulls less or not at all at low brake pedal pressure.
First attempt to resolve the problem was a simple four wheel brake system bleed.... no improvement. , First bled by pedal method, then used a vacuum system.
Next removed calipers, checked the pads and rotors (about 1/2 life left) and caliper motion, greased slide pins, reinstalled....no improvement.
Guessed that the calipers were not well matched, i.e. thought I had a bad caliper, probably on the right side since it was pulling left.
Bought a front brake kit including pads, rotors, and new rebuilt calipers, and also new brake hoses, installed.....still no change in the car braking... still pulls hard left at heavy brake pedal application. DAMN, this is a tough problem for a garage mechanic to solve!!
Jacked car front and rear, removed all four wheels, thoroughly inspected entire brake system. Reinstalled wheels, at first pedal application that stopped any wheel from turning, all four wheels were locked up. So statically, the brake system seems to work OK, but something is preventing the system from working under dynamic conditions when the pedal is applied firmly at road speed. Finally. rotated tires and test drove again. No change in behavior, still pulls to the left.
The only other thing I can think of is a front end alignment, but the car tracks dead straight going down the road. I have inspected the full length of the brake lines from the little manifold below the master cylinder, no "kinks" found. I have also inspected the front suspension and sway bar areas, and can't find anything that looks out of whack. I guess that I could also install new brake lines and remove and clean the little manifold that is below the master cylinder, maybe there is a restriction inside the brake lines that I cannot detect from a visual inspection.
Anybody got any next suggestions????
07-26-2019, 07:28 PM
#10
Thread Starter
Join Date: Aug 2018
Location: OH
Posts: 10
Problem was finally solved about two weeks ago. Ordered some new control arms with ball joints from Rockauto. Upon disassembly to install the new parts, found a broken front coil spring on the left front side, about one coil was sheared off on the bottom of the spring. Even though I had the front end inspected at a local and I thought trustworthy shop and the car went down the road straight, the problem all along was the broken coil spring. So when the front pitched down under hard braking, that broken coil spring caused havoc with the braking action and felt like something was wrong with the brakes. Oh well, it needed new ball joints anyway, the rubber boots were perished and I am sure that ball joints were not long for this world. And new brakes never hurt either. Would not want to be a mechanic, that was a lot of trial and error to find the real problem!!! But the last suggestion about the front end control arms and ball joints was the key to the problem, since I could not see that the coil spring was broken. The car works really good now, until something else breaks..