Rafz66riv Posted February 3, 2023 Share Posted February 3, 2023 Hello y’all, Iam stumped I’ve changed all my brake lines,fitting,hoses,all the whee cylinders,pads,springs. And all four of my wheels are locking up! The only thing I haven’t changed is my master cylinder and my brake booster. Has anyone had this similar issue? If so how did you fix it? thank you Link to comment Share on other sites More sharing options...
Wayne R Posted February 3, 2023 Share Posted February 3, 2023 (edited) A few things that may help, A---loose front wheel bearings. B---Loose brake backing plates. C---Shoes not properly adjusted. D---Brake shoe linings reversed, the primary lining is shorter than the secondary lining and of different composition. E---Charred linings or scored drums. Edited February 3, 2023 by Wayne R (see edit history) Link to comment Share on other sites More sharing options...
Wayne R Posted February 3, 2023 Share Posted February 3, 2023 A couple of photos, when i did mine a year ago. but a 64 Electra convertible. Link to comment Share on other sites More sharing options...
EmTee Posted February 3, 2023 Share Posted February 3, 2023 Someone else on this forum has complained of a similar issue recently. In that case, only one or two wheels were dragging and the brake lights were coming on without depressing the pedal. Suggestions in that case were to check the master cylinder - especially the push rod and the booster. First, make sure that the pedal returns properly and that when at rest, the rod hasn't moved the master cylinder. Check the shop manual for the correct lash specification. Link to comment Share on other sites More sharing options...
1965rivgs Posted February 3, 2023 Share Posted February 3, 2023 10 hours ago, Rafz66riv said: Hello y’all, Iam stumped I’ve changed all my brake lines,fitting,hoses,all the whee cylinders,pads,springs. And all four of my wheels are locking up! The only thing I haven’t changed is my master cylinder and my brake booster. Has anyone had this similar issue? If so how did you fix it? thank you A better description is necessary...by locking up, do you mean they are "touchy" and over- brake when the pedal is applied or do you mean they get to the point where the wheels will not turn after operation and while the car is at rest? Tom Mooney 1 Link to comment Share on other sites More sharing options...
Rafz66riv Posted February 3, 2023 Author Share Posted February 3, 2023 27 minutes ago, 1965rivgs said: A better description is necessary...by locking up, do you mean they are "touchy" and over- brake when the pedal is applied or do you mean they get to the point where the wheels will not turn after operation and while the car is at rest? Tom Mooney The wheels won’t turn while the car is at rest. And I have to have it a lot for it to move. And it’s all 4 wheels Link to comment Share on other sites More sharing options...
Rafz66riv Posted February 3, 2023 Author Share Posted February 3, 2023 (edited) 1 hour ago, EmTee said: Someone else on this forum has complained of a similar issue recently. In that case, only one or two wheels were dragging and the brake lights were coming on without depressing the pedal. Suggestions in that case were to check the master cylinder - especially the push rod and the booster. First, make sure that the pedal returns properly and that when at rest, the rod hasn't moved the master cylinder. Check the shop manual for the correct lash specification. Do I have to take the master cylinder off to do adjust it? Or can I adjust it from inside the car? And my brake light don’t stay on when it happens and the pedal comes back like its supposed to. the only thing I haven’t don’t to use turn my drums could not doing them cause they this to happen? Edited February 3, 2023 by Rafz66riv (see edit history) Link to comment Share on other sites More sharing options...
1965rivgs Posted February 3, 2023 Share Posted February 3, 2023 50 minutes ago, Rafz66riv said: The wheels won’t turn while the car is at rest. And I have to have it a lot for it to move. And it’s all 4 wheels Something is wrong with the master cylinder. It is not allowing the fluid back into the reservoir and you are developing pressure in the system. I`m assuming the brake shoes are installed and adjusted properly. While the brakes are locked up and you open a bleeder screw to relieve the system pressure do the wheels then spin freely? I`m assuming the answer is yes. Check to be sure the brake booster pushrod is not holding the master cylinder piston short of its stop in the master cylinder which would prevent the system pressure from returning into the master cylinder reservoir. There should be some space or "freeplay" between the pushrod and the piston in the master cylinder in order for the piston to fully retract. Tom Mooney 1 Link to comment Share on other sites More sharing options...
1965rivgs Posted February 3, 2023 Share Posted February 3, 2023 55 minutes ago, Rafz66riv said: Do I have to take the master cylinder off to do adjust it? Or can I adjust it from inside the car? And my brake light don’t stay on when it happens and the pedal comes back like its supposed to. the only thing I haven’t don’t to use turn my drums could not doing them cause they this to happen? You cant do it from inside the car and your brake lights wouldnt be affected because you have a brake light switch which is coordinated with brake pedal position and not system pressure. Turning the drums has nothing to do with your problem. Loosen the master cylinder and move it away from the brake booster by at least a couple of inches. Do the brakes free up? If so, the pushrod is likely holding the master cylinder piston from fully retracting. If not, there is probably something wrong with your master which is not allowing the system pressure to return to the master cylinder reservoir. Tom Mooney Link to comment Share on other sites More sharing options...
Rafz66riv Posted February 3, 2023 Author Share Posted February 3, 2023 1 minute ago, 1965rivgs said: You cant do it from inside the car and your brake lights wouldnt be affected because you have a brake light switch which is coordinated with brake pedal position and not system pressure. Turning the drums has nothing to do with your problem. Loosen the master cylinder and move it away from the brake booster by at least a couple of inches. Do the brakes free up? If so, the pushrod is likely holding the master cylinder piston from fully retracting. If not, there is probably something wrong with your master which is not allowing the system pressure to return to the master cylinder reservoir. Tom Mooney Oh alright, Iam going to do that today once I get back from school. thank you for the help 🙏🏽 Link to comment Share on other sites More sharing options...
Rafz66riv Posted February 3, 2023 Author Share Posted February 3, 2023 38 minutes ago, 1965rivgs said: You cant do it from inside the car and your brake lights wouldnt be affected because you have a brake light switch which is coordinated with brake pedal position and not system pressure. Turning the drums has nothing to do with your problem. Loosen the master cylinder and move it away from the brake booster by at least a couple of inches. Do the brakes free up? If so, the pushrod is likely holding the master cylinder piston from fully retracting. If not, there is probably something wrong with your master which is not allowing the system pressure to return to the master cylinder reservoir. Tom Mooney Also when I move the master cylinder to I discount the line going to it or do I leave it on? Link to comment Share on other sites More sharing options...
1965rivgs Posted February 3, 2023 Share Posted February 3, 2023 27 minutes ago, Rafz66riv said: Oh alright, Iam going to do that today once I get back from school. thank you for the help 🙏🏽 I would be surprised if your problem involves the master cylinder pushrod freeplay because, from your description, you didnt touch the master or booster. Once adjusted, brake pedal freeplay doesnt "just change". Maybe something happened to the internals of the master cylinder in the bleeding process? Maybe the piston is hanging up in its bore and not allowing brake fluid back into the master reservoir? Did you apply the brake pedal all the way to the floor during the bleeding process? Most people do....I learned a long time ago that, if it can be accomplished, gravity bleeding always comes first in order to fill the system with fresh brake fluid and eliminate air, before the full brake pedal application method. The reason I use this method and avoid full pedal application is because when doing so you are pushing the master cylinder piston through an area in the master cylinder which it doesnt move through during normal operation. As a result, corrosion or just dirt/grime in the cylinder bore can ruin the rubber parts on the piston and result in a bad master cylinder when it was operational before bleeding. I learned this through experience, as many times after using full brake pedal application for bleeding while servicing brake hydraulic brake components other than the master cylinder, I ended up also changing out a master cylinder. There is also the consideration that it is possible to introduce air, which is initially suspended in the brake fluid, through aeration by repeated and swift application of the brake pedal. Every time a see techs or weekend warriors bleed brakes with a partner by exclaiming "pump it up!" to initially fill the system with fluid I cringe. I have had great success with gravity bleeding for 50 years and that includes modern ABS systems. Good luck! Tom mooney Link to comment Share on other sites More sharing options...
1965rivgs Posted February 3, 2023 Share Posted February 3, 2023 (edited) 1 hour ago, Rafz66riv said: Also when I move the master cylinder to I discount the line going to it or do I leave it on? Leave the line installed and the system sealed. If you relieve pressure in the system by removing a line you will defeat the purpose of this troubleshooting step. Just move the master away from the booster and slightly bend the brake line, away from the ends, while doing so. The lines will bend back when you reinstall. Dont bend or kink the brake line at the ends! Tom Edited February 3, 2023 by 1965rivgs (see edit history) Link to comment Share on other sites More sharing options...
Rafz66riv Posted February 3, 2023 Author Share Posted February 3, 2023 10 minutes ago, 1965rivgs said: I would be surprised if your problem involves the master cylinder pushrod freeplay because, from your description, you didnt touch the master or booster. Once adjusted, brake pedal freeplay doesnt "just change". Maybe something happened to the internals of the master cylinder in the bleeding process? Maybe the piston is hanging up in its bore and not allowing brake fluid back into the master reservoir? Did you apply the brake pedal all the way to the floor during the bleeding process? Most people do....I learned a long time ago that, if it can be accomplished, gravity bleeding always comes first in order to fill the system with fresh brake fluid and eliminate air, before the full brake pedal application method. The reason I use this method and avoid full pedal application is because when doing so you are pushing the master cylinder piston through an area in the master cylinder which it doesnt move through during normal operation. As a result, corrosion or just dirt/grime in the cylinder bore can ruin the rubber parts on the piston and result in a bad master cylinder when it was operational before bleeding. I learned this through experience, as many times after using full brake pedal application for bleeding while servicing brake hydraulic brake components other than the master cylinder, I ended up also changing out a master cylinder. There is also the consideration that it is possible to introduce air, which is initially suspended in the brake fluid, through aeration by repeated and swift application of the brake pedal. Every time a see techs or weekend warriors bleed brakes with a partner by exclaiming "pump it up!" to initially fill the system with fluid I cringe. I have had great success with gravity bleeding for 50 years and that includes modern ABS systems. Good luck! Tom mooney Yeah, when I bleed them we would out the pedal to the floor. The master cylinder is original to the car and was pretty nasty inside the revisor so Iam sure I probably have to change it out now Link to comment Share on other sites More sharing options...
Rafz66riv Posted February 3, 2023 Author Share Posted February 3, 2023 7 minutes ago, 1965rivgs said: Leave the line installed and the system sealed. If you relieve pressure in the system by removing a line you will defeat the purpose of this troubleshooting step. Just move the master away from the booster and slightly bend the brake line away from the ends while doing so. The lines will bend back when you reinstall. Dont bend or kink the brake line at the ends! Tom Alright I’ll make sure to keep them on. I thought I should keep it in just wasn’t sure. thank you Link to comment Share on other sites More sharing options...
Rafz66riv Posted February 4, 2023 Author Share Posted February 4, 2023 8 hours ago, 1965rivgs said: Leave the line installed and the system sealed. If you relieve pressure in the system by removing a line you will defeat the purpose of this troubleshooting step. Just move the master away from the booster and slightly bend the brake line, away from the ends, while doing so. The lines will bend back when you reinstall. Dont bend or kink the brake line at the ends! Tom I just got home and I turned in the car and put it in drive and the brakes were no longer locked up. It would still make sense for it to the the master cylinder, or is there something else it could be? Link to comment Share on other sites More sharing options...
Seafoam65 Posted February 4, 2023 Share Posted February 4, 2023 It can only be the master cylinder is bad or the push rod on the booster is too long. Bad brake hoses can do this but you said you changed them already. 1 Link to comment Share on other sites More sharing options...
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