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Discussion Topic:
Brake system lock-up issue
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37RAGTOPMAN |
08-21-2023 @ 3:43 PM
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Senior
Posts: 1958
Joined: Oct 2009
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HI Do not rule out the 3 rubber flex lines, they can also rupture internal and cause problems like locking up the brakes does only one wheel lock up ? might be a good time to replace them. hope this helps 37Ragtopman , Maine
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RAK402 |
08-19-2023 @ 3:56 PM
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Member
Posts: 436
Joined: Jul 2015
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Drbrown, Thank you for the detailed information sir-I did not know these existed! Very cool!
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kubes40 |
08-19-2023 @ 7:31 AM
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Senior
Posts: 3394
Joined: Oct 2009
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The fluid will most likely not show any issues. The pistons are where the issue shows up. Ya can't know until the wheel cylinder is disassembled. I'd place a healthy size bet; the cylinders are not "healthy". There may very well be a lot of white corrosion built up at the cylinders. That hinders the travel of the piston. As it gets worse, the piston will be forced out (hydraulic pressure) but will be unable to retract properly. Mike "Kube" Kubarth
This message was edited by kubes40 on 8-19-23 @ 5:21 PM
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Drbrown |
08-09-2023 @ 11:09 PM
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Senior
Posts: 570
Joined: Nov 2013
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kubes40: I agree. We did collect the fluid individually from each wheel cylinder and inspect it. To the good, the fluid did not show any moisture or decoloring.
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Drbrown |
08-09-2023 @ 11:03 PM
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Senior
Posts: 570
Joined: Nov 2013
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RAK402: As best I can describe ..... With stock air bleeder fittings at the individual wheel cylinders, it takes two persons to bleed air out of the brake system through the individual wheel cylinders ..... one person to apply and keep a steady pressure at the foot pedal and one person under the car to open and close the bleeder valve to release any trapped air out of each wheel cylinder. If the fluid runs low during this procedure or foot pressure is removed from the pedal, air can get sucked back into the cylinder thru the open valve. By replacing the stock bleeder valves with the so-called self-bleeder valves only one person is needed to do the operation. The self-bleeder valves at the cylinders have an internal valve that closes when foot pressure is removed thus preventing air from being sucked back in. SO one person can open the self-bleeder fitting at a wheel cylinder then go top-side and apply pressure on the foot pedal to force air out the bleeder. The master cylinder must be kept full at all times when doing this. So as normal, start at the wheel furthest from the master cylinder and attach a drain hose to the valve to collect the fluid in a container. Apply pressure to foot pedal enough to assure that all air at the wheel cylinder has been forced out. Keep master cylinder full. Tighten valve fitting at wheel when done. You should have a good solid feel when applying the brake pedal. I bought the self-bleeder fittings (two to a package) several years ago from one of the Ford suppliers. Be sure to get the ones with the correct tread size.
This message was edited by Drbrown on 8-10-23 @ 10:05 PM
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RAK402 |
08-08-2023 @ 7:23 PM
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Member
Posts: 436
Joined: Jul 2015
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DrBrown, I have to ask-What are self-bleeding brake fittings?
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kubes40 |
08-08-2023 @ 2:55 PM
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Senior
Posts: 3394
Joined: Oct 2009
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It would have been prudent to disassemble each wheel cylinder. After twelve years, there's a great chance that one or more are "gummed up". Although the issue you had has not reoccurred, my money is on "it will". You might be amazed at how corroded the cylinders can become.
Mike "Kube" Kubarth
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Drbrown |
08-08-2023 @ 12:50 PM
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Senior
Posts: 570
Joined: Nov 2013
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Concern regarding my apparent system lock-up event remains unexplained. Had system inspected and flushed. Installed self-bleeding fittings at wheel cylinders. Master cylinder looks and functions fine. Pedal and master cylinder rod freeplay were and are at what they should be. Wheel cylinders function and no leakage found. Brake shoes still set at proper positions. The system had not been flushed in 12 years or more. The brake pedal now feels stronger than before.
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Drbrown |
07-29-2023 @ 8:56 AM
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Senior
Posts: 570
Joined: Nov 2013
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Thanks to all. The brake system had been working fine; good solid pedal and even stopping. I wonder to myself if the lock up was a fluke i.e. the pedal or MC rod didn't properly return .... at the incident I didn't look at or feel the pedal for any free-play. I'll look at the items suggested and jack the car to make sure each wheel is braking. I found Tom'Os old post with copies of factory manual on how to do adjustments.
This message was edited by Drbrown on 7-29-23 @ 8:58 AM
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kubes40 |
07-29-2023 @ 8:43 AM
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Senior
Posts: 3394
Joined: Oct 2009
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Most likely one of two issues. Perhaps both. 1) Master cylinder rod is adjusted too long. That causes a delay or even a stop in the fluid being allowed back into the master. the brake pedal will become harder each time you press it down. Let it sit overnight and most likely, the pedal will feel fine. 2) Brake shoes are adjusted too close to the drums. Shoes heat up and drag. I'd start at the master rod.
Mike "Kube" Kubarth
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