Brake failure

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green47tc
Posts: 9
Joined: Mon Jun 20, 2005 9:02 am

Brake failure

Post by green47tc » Tue Feb 07, 2017 7:44 pm

Seems to be a lot of argument over unimportant items. Anyone who drives in Los Angeles knows that brakes are just a back up system in case your horn or your 9 mm won't clear your pathway.  (though it is hard for a TC to intimidate someone in an Escalade) gene olson

Norman Verona
Posts: 107
Joined: Sun May 17, 2015 4:21 am

Re: Brake Failure

Post by Norman Verona » Wed Feb 08, 2017 12:39 am

Bill, all you say is true but only applies to cars from about the 70 s. The earlier cars had very basic brakes. Minors, Minis, Cortina s etc were always prone to brake problems.

 

[b]Norman Verona[/b]

La Foie, 49520, Noellet, France

Tel: 0033 (0)2 41 92 73 44

Mob: 0033 (0)7 70 70 23 79

Website: www FrenchBlat com (put dots in the spaces)

 

[b]From:[/b] Bill Hyatt [mailto:usaj24@earthlink.net] [b]Sent:[/b] 07 February 2017 22:12 [b]To:[/b] 'Clive P Sherriff' csherriff99@gmail.com>; 'Stephen D Stierman' morgan7709@sbcglobal.net>; 'Norman Verona' norman@frenchblat.com>; 'Steve S' mail@mgnuts.com>; 'MG tabcgroups' MG-tabc@yahoogroups.com> [b]Subject:[/b] RE: [mg-tabc] Brake Failure

 

Guys,

Hydraulic brake technology has been mainstream for 75 years in daily drivers. During that time some improvements such as anti-lockup et. al. have been made.. Basically, with proper maintenance it is virtually fool proof. Catastrophic failures are very very rare, though not impossible. Usually traced to maintenance problem, rarely to a design failure.

 

Bill

TC 4926

Odessa, Fl

 

[b]From:[/b] mg-tabc@yahoogroups.com [mg-tabc@yahoogroups.com] [b]On Behalf Of [/b]'Clive P Sherriff' csherriff99@gmail.com [mg-tabc] [b]Sent:[/b] Wednesday, February 08, 2017 2:44 PM [b]To:[/b] Stephen D Stierman; Norman Verona; 'Steve S'; 'MG tabcgroups' [b]Subject:[/b] Re: [mg-tabc] Brake Failure

 

 

Steve,

 

you say  >> Unless of course all the hydraulics have just been rebuilt/replaced 

 

I'd say that was the most important reason to check absolutely everything !

 

(Unless I'd rebuilt them of course !

 

Clive

= ==================================

----- Original Message -----

[b]From:[/b] morgan7709@sbcglobal.net%20[mg-tabc]

[b]To:[/b] norman@frenchblat.com ; mail@mgnuts.com ; MG-tabc@yahoogroups.com

[b]Sent:[/b] Tuesday, February 07, 2017 2:56 PM

[b]Subject:[/b] Re: [mg-tabc] Brake Failure

 

 

Norman,

I am not necessarily debating your premise that the MC is at fault, what I am saying is before the OP decides that is the problem, he ought take a good close look at the rest of system to be sure nothing else has gone south.  Unless of course all the hydraulics have just been rebuilt/replaced which still doesn't guarantee that there is not a problem.  Additionally you are taking his description of events at face value and his explanation may not be quite the same as mine should I experience a similar situation. 

Steve TC2911

[b]From:[/b] "'Norman Verona' norman@frenchblat.com [mg-tabc]" mg-tabc-noreply@yahoogroups.com> [b]To:[/b] 'Stephen D Stierman' morgan7709@sbcglobal.net>; 'Steve S' mail@mgnuts.com>; 'MG tabcgroups' MG-tabc@yahoogroups.com> [b]Sent:[/b] Tuesday, February 7, 2017 9:19 AM [b]Subject:[/b] RE: [mg-tabc] Brake Failure

 

 

Steve, I agree. However the report said the pedal was hard one day and no brakes at all the next. A master cylinder with mixed air and fluid will give a spongy pedal which will pump up to hard is pumped. However a cylinder which is completely empty will have a pedal which goes to the floor and will not pump up.

 

Do you disagree?

 

[b]Norman Verona[/b]

La Foie, 49520, Noellet, France

Tel: 0033 (0)2 41 92 73 44

Mob: 0033 (0)7 70 70 23 79

Website: www FrenchBlat com (put dots in the spaces)

 

[b]From:[/b] Stephen D Stierman [morgan7709@sbcglobal.net] [b]Sent:[/b] 07 February 2017 12:19 [b]To:[/b] Norman Verona norman@frenchblat.com>; 'Steve S' mail@mgnuts.com>; 'MG tabcgroups' MG-tabc@yahoogroups.com> [b]Subject:[/b] Re: [mg-tabc] Brake Failure

 

Not so Norman,

As Steve points out and I have found personally, enough air entering via wheel cylinder(s) and a bit of loss at the same place, will cause a peddle to become softer over time, eventually causing brake actuation to become almost nil.

Steve TC2911

 

From: "'Norman Verona' norman@frenchblat.com [mg-tabc]" mg-tabc-noreply@yahoogroups.com> [b]To:[/b] 'Steve S' mail@mgnuts.com>; 'MG tabcgroups' MG-tabc@yahoogroups.com> [b]Sent:[/b] Tuesday, February 7, 2017 4:25 AM [b]Subject:[/b] RE: [mg-tabc] Brake Failure

 

 

Steve, the point is the OP said there was no signs of a leak. To get total brake failure the master cylinder must empty completely. And to get sudden total failure the leak must be substantial. I have suggested that before going for the unusual, with the master cylinder the wheel cylinders and the brake pipes are inspected. It would appear we are talking a substantial leak so it should be clearly visible.

 

[b]Norman Verona[/b]

La Foie, 49520, Noellet, France

Tel: 0033 (0)2 41 92 73 44

Mob: 0033 (0)7 70 70 23 79

Website: www FrenchBlat com (put dots in the spaces)

 

[b]From:[/b] mg-tabc@yahoogroups.com [mg-tabc@yahoogroups.com] [b]On Behalf Of [/b]Steve S mail@mgnuts.com [mg-tabc] [b]Sent:[/b] 07 February 2017 09:25 [b]To:[/b] 'MG tabcgroups' MG-tabc@yahoogroups.com> [b]Subject:[/b] Re: [mg-tabc] Brake Failure

 

 

It takes very little air to cause massive brake fade.  When you bleed the brakes, each pump yields a lot of fluid with a small amount of bubbles.  However the brakes go from soft to firm.  If you somehow had enough air coming in from below to displace 3/4" of fluid in the cylinder and overflow it, you'd probably completely empty all four cylinders and half of the hard lines!

- Steve Simmons, TC8975

 

On 2/6/2017 11:49 PM, 'Norman Verona' norman@frenchblat.com [mg-tabc] wrote:

 

Steve,

 

In which case the fluid would be overflowing from the master.

 

[b]Norman Verona[/b]

La Foie, 49520, Noellet, France

Tel: 0033 (0)2 41 92 73 44

Mob: 0033 (0)7 70 70 23 79

Website: www FrenchBlat com (put dots in the spaces)

 

[b]From:[/b] mg-tabc@yahoogroups.com [mg-tabc@yahoogroups.com] [b]On Behalf Of [/b]Steve S mail@mgnuts.com [mg-tabc] [b]Sent:[/b] 07 February 2017 02:48 [b]To:[/b] MG tabcgroups MG-tabc@yahoogroups.com [b]Subject:[/b] Re: [mg-tabc] Brake Failure

 

 

Agreed.  Air can definitely come in past the wheel cylinder cups.  No leak necessary.  If the master cylinder returns faster than the brake shoes, air can be pulled in.  Ensure the brake springs are all in correct working condition to prevent it from happening.

- Steve Simmons, TC8975

 

On 2/6/2017 5:26 PM, Stephen D Stierman morgan7709@sbcglobal.net [mg-tabc] wrote:

 

I had a continual problems with air entering the braking system, likely comi! ng via wheel cylinder(s) that may have been seeping slightly, don't discard that end of the system as the problem.  Bleeding would result in a hard peddle that over time would become softer in use.

Steve TC2911

 

[b]From:[/b] "James Davis burburyclose@yahoo.com [mg-tabc]" mg-tabc-noreply@yahoogroups.com [b]To:[/b] Mg-Tabc mg-tabc@yahoogroups.com [b]Sent:[/b] Monday, February 6, 2017 5:02 PM [b]Subject:[/b] [mg-tabc] Brake Failure

 

 

Thanks to all of you for your ideas. I checked the brake lines,MC, etc with no indication of leakage. Then I bled the line out. Much air in there. The brakes came back after bleeding. Perhaps when I tested the brakes HARD the day before, I explosed some intermittent crack etc in the system which only shows up with hard use. I plan to give it a rigorous test after my diff comes back from being worked over. I'm on pins and needles driving it now and will try to break the fault during the next hard test. I'll keep the group informed. Thanks again. Jim Davis TC 7225 Houston

 

 

 

 

 

 

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John Kallend
Posts: 17
Joined: Sun Mar 17, 2013 7:50 am

Re: Brake Failure

Post by John Kallend » Wed Feb 08, 2017 5:59 am

TC0845 ran for decades on its original brake hardware. Corrosion eventually forced me to systematically replace cylinders. Only since using aftermarket products has it encountered problems (mostly related to wheel cylinder seal leakage.) _____________________________John KallendProfessor EmeritusDepartment of Mechanical, Materials and Aerospace EngineeringDepartment of PhysicsIIT, Chicago
On Wed, Feb 8, 2017 at 2:36 AM, 'Norman Verona' norman@frenchblat.com [mg-tabc] mg-tabc-noreply@yahoogroups.com> wrote: [u][/u] Bill, all you say is true but only applies to cars from about the 70 s. The earlier cars had very basic brakes. Minors, Minis, Cortina s etc were always prone to brake problems.[u][/u][u][/u]

[u][/u] [u][/u]

[b]Norman Verona[u][/u][u][/u][/b]

La Foie, 49520, Noellet, France[u][/u][u][/u]

Tel: 0033 (0)2 41 92 73 44[u][/u][u][/u]

Mob: 0033 (0)7 70 70 23 79[u][/u][u][/u]

Website: www FrenchBlat com (put dots in the spaces)[u][/u][u][/u]

[u][/u] [u][/u]

[b]From:[/b] Bill Hyatt [mailto:usaj24@earthlink.net] [b]Sent:[/b] 07 February 2017 22:12 [b]To:[/b] 'Clive P Sherriff' csherriff99@gmail.com>; 'Stephen D Stierman' morgan7709@sbcglobal.net>; 'Norman Verona' norman@frenchblat.com>; 'Steve S' mail@mgnuts.com>; 'MG tabcgroups' MG-tabc@yahoogroups.com> [b]Subject:[/b] RE: [mg-tabc] Brake Failure[u][/u][u][/u]

[u][/u] [u][/u]

Guys, [u][/u][u][/u]

Hydraulic brake technology has been mainstream for 75 years in daily drivers. During that time some improvements such as anti-lockup et. al. have been made.. Basically, with proper maintenance it is virtually fool proof. Catastrophic failures are very very rare, though not impossible. Usually traced to maintenance problem, rarely to a design failure.[u][/u][u][/u]

[u][/u] [u][/u]

Bill [u][/u][u][/u]

TC 4926[u][/u][u][/u]

Odessa, Fl[u][/u][u][/u]

[u][/u] [u][/u]

[b]From:[/b] mg-tabc@yahoogroups.com [mg-tabc@yahoogroups.com] [b]On Behalf Of [/b]'Clive P Sherriff' csherriff99@gmail.com [mg-tabc] [b]Sent:[/b] Wednesday, February 08, 2017 2:44 PM [b]To:[/b] Stephen D Stierman; Norman Verona; 'Steve S'; 'MG tabcgroups' [b]Subject:[/b] Re: [mg-tabc] Brake Failure[u][/u][u][/u]

[u][/u] [u][/u]

[u][/u][u][/u]

[u][/u][u][/u]Steve, [u][/u][u][/u]

[u][/u][u][/u]

you say >> Unless of course all the hydraulics have just been rebuilt/replaced

[u][/u][u][/u]

I'd say that was the most important reason to check absolutely everything ![u][/u][u][/u]

[u][/u][u][/u]

(Unless I'd rebuilt them of course ! [u][/u][u][/u]

[u][/u][u][/u]

Clive[u][/u][u][/u]

= ============================== ====[u][/u][u][/u]

----- Original Message ----- [u][/u][u][/u]

[b]From:[/b] morgan7709@sbcglobal.net%20[mg-tabc] [u][/u][u][/u]

[b]To:[/b] norman@frenchblat.com ; mail@mgnuts.com ; MG-tabc@yahoogroups.com [u][/u][u][/u]

[b]Sent:[/b] Tuesday, February 07, 2017 2:56 PM[u][/u][u][/u]

[b]Subject:[/b] Re: [mg-tabc] Brake Failure[u][/u][u][/u]

[u][/u] [u][/u]

[u][/u][u][/u]

Norman,[u][/u][u][/u]

I am not necessarily debating your premise that the MC is at fault, what I am saying is before the OP decides that is the problem, he ought take a good close look at the rest of system to be sure nothing else has gone south. Unless of course all the hydraulics have just been rebuilt/replaced which still doesn't guarantee that there is not a problem. Additionally you are taking his description of events at face value and his explanation may not be quite the same as mine should I experience a similar situation. [u][/u][u][/u]

Steve TC2911[u][/u][u][/u]

[b]From:[/b] "'Norman Verona' norman@frenchblat.com [mg-tabc]" mg-tabc-noreply@yahoogroups.com> [b]To:[/b] 'Stephen D Stierman' morgan7709@sbcglobal.net>; 'Steve S' mail@mgnuts.com>; 'MG tabcgroups' MG-tabc@yahoogroups.com> [b]Sent:[/b] Tuesday, February 7, 2017 9:19 AM [b]Subject:[/b] RE: [mg-tabc] Brake Failure[u][/u][u][/u]

[u][/u] [u][/u]

[u][/u][u][/u]

Steve, I agree. However the report said the pedal was hard one day and no brakes at all the next. A master cylinder with mixed air and fluid will give a spongy pedal which will pump up to hard is pumped. However a cylinder which is completely empty will have a pedal which goes to the floor and will not pump up.[u][/u][u][/u]

[u][/u][u][/u]

Do you disagree?[u][/u][u][/u]

[u][/u][u][/u]

[b]Norman Verona[/b][u][/u][u][/u]

La Foie, 49520, Noellet, France[u][/u][u][/u]

Tel: 0033 (0)2 41 92 73 44[u][/u][u][/u]

Mob: 0033 (0)7 70 70 23 79[u][/u][u][/u]

Website: www FrenchBlat com (put dots in the spaces)[u][/u][u][/u]

[u][/u][u][/u]

[b]From:[/b] Stephen D Stierman [morgan7709@sbcglobal.net] [b]Sent:[/b] 07 February 2017 12:19 [b]To:[/b] Norman Verona norman@frenchblat.com>; 'Steve S' mail@mgnuts.com>; 'MG tabcgroups' MG-tabc@yahoogroups.com> [b]Subject:[/b] Re: [mg-tabc] Brake Failure[u][/u][u][/u]

[u][/u][u][/u]

Not so Norman,[u][/u][u][/u]

As Steve points out and I have found personally, enough air entering via wheel cylinder(s) and a bit of loss at the same place, will cause a peddle to become softer over time, eventually causing brake actuation to become almost nil.[u][/u][u][/u]

Steve TC2911[u][/u][u][/u]

[u][/u][u][/u]

From: "'Norman Verona' norman@frenchblat.com [mg-tabc]" mg-tabc-noreply@yahoogroups.com> [b]To:[/b] 'Steve S' mail@mgnuts.com>; 'MG tabcgroups' MG-tabc@yahoogroups.com> [b]Sent:[/b] Tuesday, February 7, 2017 4:25 AM [b]Subject:[/b] RE: [mg-tabc] Brake Failure[u][/u][u][/u]

[u][/u][u][/u]

[u][/u][u][/u]

Steve, the point is the OP said there was no signs of a leak. To get total brake failure the master cylinder must empty completely. And to get sudden total failure the leak must be substantial. I have suggested that before going for the unusual, with the master cylinder the wheel cylinders and the brake pipes are inspected. It would appear we are talking a substantial leak so it should be clearly visible.[u][/u][u][/u]

[u][/u][u][/u]

[b]Norman Verona[/b][u][/u][u][/u]

La Foie, 49520, Noellet, France[u][/u][u][/u]

Tel: 0033 (0)2 41 92 73 44[u][/u][u][/u]

Mob: 0033 (0)7 70 70 23 79[u][/u][u][/u]

Website: www FrenchBlat com (put dots in the spaces)[u][/u][u][/u]

[u][/u][u][/u]

[b]From:[/b] mg-tabc@yahoogroups.com [mg-tabc@yahoogroups.com] [b]On Behalf Of [/b]Steve S mail@mgnuts.com [mg-tabc] [b]Sent:[/b] 07 February 2017 09:25 [b]To:[/b] 'MG tabcgroups' MG-tabc@yahoogroups.com> [b]Subject:[/b] Re: [mg-tabc] Brake Failure[u][/u][u][/u]

[u][/u][u][/u]

[u][/u][u][/u]

It takes very little air to cause massive brake fade. When you bleed the brakes, each pump yields a lot of fluid with a small amount of bubbles. However the brakes go from soft to firm. If you somehow had enough air coming in from below to displace 3/4" of fluid in the cylinder and overflow it, you'd probably completely empty all four cylinders and half of the hard lines![u][/u][u][/u]

- Steve Simmons, TC8975[u][/u][u][/u]

[u][/u][u][/u]

On 2/6/2017 11:49 PM, 'Norman Verona' norman@frenchblat.com [mg-tabc] wrote:[u][/u][u][/u]

[u][/u][u][/u]

Steve,[u][/u][u][/u]

[u][/u][u][/u]

In which case the fluid would be overflowing from the master.[u][/u][u][/u]

[u][/u][u][/u]

[b]Norman Verona[/b][u][/u][u][/u]

La Foie, 49520, Noellet, France[u][/u][u][/u]

Tel: 0033 (0)2 41 92 73 44[u][/u][u][/u]

Mob: 0033 (0)7 70 70 23 79[u][/u][u][/u]

Website: www FrenchBlat com (put dots in the spaces)[u][/u][u][/u]

[u][/u][u][/u]

[b]From:[/b] mg-tabc@yahoogroups.com [mg-tabc@yahoogroups.com] [b]On Behalf Of [/b]Steve S mail@mgnuts.com [mg-tabc] [b]Sent:[/b] 07 February 2017 02:48 [b]To:[/b] MG tabcgroups MG-tabc@yahoogroups.com [b]Subject:[/b] Re: [mg-tabc] Brake Failure[u][/u][u][/u]

[u][/u][u][/u]

[u][/u][u][/u]

Agreed. Air can definitely come in past the wheel cylinder cups. No leak necessary. If the master cylinder returns faster than the brake shoes, air can be pulled in. Ensure the brake springs are all in correct working condition to prevent it from happening.[u][/u][u][/u]

- Steve Simmons, TC8975[u][/u][u][/u]

[u][/u][u][/u]

On 2/6/2017 5:26 PM, Stephen D Stierman morgan7709@sbcglobal.net [mg-tabc] wrote:[u][/u][u][/u]

[u][/u][u][/u]

I had a continual problems with air entering the braking system, likely comi! ng via wheel cylinder(s) that may have been seeping slightly, don't discard that end of the system as the problem. Bleeding would result in a hard peddle that over time would become softer in use.[u][/u][u][/u]

Steve TC2911[u][/u][u][/u]

[u][/u][u][/u]

[b]From:[/b] "James Davis burburyclose@yahoo.com [mg-tabc]" mg-tabc-noreply@yahoogroups.com [b]To:[/b] Mg-Tabc mg-tabc@yahoogroups.com [b]Sent:[/b] Monday, February 6, 2017 5:02 PM [b]Subject:[/b] [mg-tabc] Brake Failure[u][/u][u][/u]

[u][/u][u][/u]

[u][/u][u][/u]

Thanks to all of you for your ideas. I checked the brake lines,MC, etc with no indication of leakage. Then I bled the line out. Much air in there. The brakes came back after bleeding. Perhaps when I tested the brakes HARD the day before, I explosed some intermittent crack etc in the system which only shows up with hard use. I plan to give it a rigorous test after my diff comes back from being worked over. I'm on pins and needles driving it now and will try to break the fault during the next hard test. I'll keep the group informed. Thanks again. Jim Davis TC 7225 Houston[u][/u][u][/u]

[u][/u][u][/u]

[u][/u][u][/u]

[u][/u][u][/u]

[u][/u][u][/u]

[u][/u] [u][/u]

[u][/u] [u][/u]

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e_callo
Posts: 22
Joined: Mon Feb 04, 2013 7:20 am

Re: Brake Failure

Post by e_callo » Wed Feb 08, 2017 6:11 am

Maybe not in Florida, but here in the northeast the stuff they put on the road will rust through brake lines on a new car and then boom - no brakes.  Truckers have been complaining to the State of CT about it for the last few years.  So yes, brakes will fail on even new cars   Ed   In a message dated 2/7/2017 4:12:43 P.M. Eastern Standard Time, mg-tabc-noreply@yahoogroups.com writes:
[color=#000000]  Guys, Hydraulic brake technology has been mainstream for 75 years in daily drivers. During that time some improvements such as anti-lockup et. al. have been made.. Basically, with proper maintenance it is virtually fool proof. Catastrophic failures are very very rare, though not impossible. Usually traced to maintenance problem, rarely to a design failure.

Bill

TC 4926

Odessa, Fl

[b]From:[/b] mg-tabc@yahoogroups.com [mailto:mg-tabc@yahoogroups.com] [b]On Behalf Of [/b]'Clive P Sherriff' csherriff99@gmail.com [mg-tabc] [b]Sent:[/b] Wednesday, February 08, 2017 2:44 PM [b]To:[/b] Stephen D Stierman; Norman Verona; 'Steve S'; 'MG tabcgroups' [b]Subject:[/b] Re: [mg-tabc] Brake Failure

 

Steve,

you say  >> Unless of course all the hydraulics have just been rebuilt/replaced 

I'd say that was the most important reason to check absolutely everything !

(Unless I'd rebuilt them of course !

Clive

= ==================================

----- Original Message -----

[b]From:[/b] morgan7709@sbcglobal.net%20[mg-tabc]

[b]To:[/b] norman@frenchblat.com ; mail@mgnuts.com ; MG-tabc@yahoogroups.com

[b]Sent:[/b] Tuesday, February 07, 2017 2:56 PM

[b]Subject:[/b] Re: [mg-tabc] Brake Failure

 

Norman,

I am not necessarily debating your premise that the MC is at fault, what I am saying is before the OP decides that is the problem, he ought take a good close look at the rest of system to be sure nothing else has gone south.  Unless of course all the hydraulics have just been rebuilt/replaced which still doesn't guarantee that there is not a problem.  Additionally you are taking his description of events at face value and his explanation may not be quite the same as mine should I experience a similar situation. 

Steve TC2911

[b]From:[/b] "'Norman Verona' norman@frenchblat.com [mg-tabc]" mg-tabc-noreply@yahoogroups.com> [b]To:[/b] 'Stephen D Stierman' morgan7709@sbcglobal.net>; 'Steve S' mail@mgnuts.com>; 'MG tabcgroups' MG-tabc@yahoogroups.com> [b]Sent:[/b] Tuesday, February 7, 2017 9:19 AM [b]Subject:[/b] RE: [mg-tabc] Brake Failure

 

Steve, I agree. However the report said the pedal was hard one day and no brakes at all the next. A master cylinder with mixed air and fluid will give a spongy pedal which will pump up to hard is pumped. However a cylinder which is completely empty will have a pedal which goes to the floor and will not pump up.

Do you disagree?

[b]Norman Verona[/b]

La Foie, 49520, Noellet, France

Tel: 0033 (0)2 41 92 73 44

Mob: 0033 (0)7 70 70 23 79

Website: www FrenchBlat com (put dots in the spaces)

[b]From:[/b] Stephen D Stierman [morgan7709@sbcglobal.net] [b]Sent:[/b] 07 February 2017 12:19 [b]To:[/b] Norman Verona norman@frenchblat.com>; 'Steve S' mail@mgnuts.com>; 'MG tabcgroups' MG-tabc@yahoogroups.com> [b]Subject:[/b] Re: [mg-tabc] Brake Failure

Not so Norman,

As Steve points out and I have found personally, enough air entering via wheel cylinder(s) and a bit of loss at the same place, will cause a peddle to become softer over time, eventually causing brake actuation to become almost nil.

Steve TC2911

From: "'Norman Verona' norman@frenchblat.com [mg-tabc]" mg-tabc-noreply@yahoogroups.com> [b]To:[/b] 'Steve S' mail@mgnuts.com>; 'MG tabcgroups' MG-tabc@yahoogroups.com> [b]Sent:[/b] Tuesday, February 7, 2017 4:25 AM [b]Subject:[/b] RE: [mg-tabc] Brake Failure

 

Steve, the point is the OP said there was no signs of a leak. To get total brake failure the master cylinder must empty completely. And to get sudden total failure the leak must be substantial. I have suggested that before going for the unusual, with the master cylinder the wheel cylinders and the brake pipes are inspected. It would appear we are talking a substantial leak so it should be clearly visible.

[b]Norman Verona[/b]

La Foie, 49520, Noellet, France

Tel: 0033 (0)2 41 92 73 44

Mob: 0033 (0)7 70 70 23 79

Website: www FrenchBlat com (put dots in the spaces)

[b]From:[/b] mg-tabc@yahoogroups.com [mg-tabc@yahoogroups.com] [b]On Behalf Of [/b]Steve S mail@mgnuts.com [mg-tabc] [b]Sent:[/b] 07 February 2017 09:25 [b]To:[/b] 'MG tabcgroups' MG-tabc@yahoogroups.com> [b]Subject:[/b] Re: [mg-tabc] Brake Failure

 

It takes very little air to cause massive brake fade.  When you bleed the brakes, each pump yields a lot of fluid with a small amount of bubbles.  However the brakes go from soft to firm.  If you somehow had enough air coming in from below to displace 3/4" of fluid in the cylinder and overflow it, you'd probably completely empty all four cylinders and half of the hard lines!

- Steve Simmons, TC8975

On 2/6/2017 11:49 PM, 'Norman Verona' norman@frenchblat.com [mg-tabc] wrote:

 

Steve,

In which case the fluid would be overflowing from the master.

[b]Norman Verona[/b]

La Foie, 49520, Noellet, France

Tel: 0033 (0)2 41 92 73 44

Mob: 0033 (0)7 70 70 23 79

Website: www FrenchBlat com (put dots in the spaces)

[b]From:[/b] mg-tabc@yahoogroups.com [mg-tabc@yahoogroups.com] [b]On Behalf Of [/b]Steve S mail@mgnuts.com [mg-tabc] [b]Sent:[/b] 07 February 2017 02:48 [b]To:[/b] MG tabcgroups MG-tabc@yahoogroups.com [b]Subject:[/b] Re: [mg-tabc] Brake Failure

 

Agreed.  Air can definitely come in past the wheel cylinder cups.  No leak necessary.  If the master cylinder returns faster than the brake shoes, air can be pulled in.  Ensure the brake springs are all in correct working condition to prevent it from happening.

- Steve Simmons, TC8975

On 2/6/2017 5:26 PM, Stephen D Stierman morgan7709@sbcglobal.net [mg-tabc] wrote:

 

I had a continual problems with air entering the braking system, likely comi! ng via wheel cylinder(s) that may have been seeping slightly, don't discard that end of the system as the problem.  Bleeding would result in a hard peddle that over time would become softer in use.

Steve TC2911

[b]From:[/b] "James Davis burburyclose@yahoo.com [mg-tabc]" mg-tabc-noreply@yahoogroups.com [b]To:[/b] Mg-Tabc mg-tabc@yahoogroups.com [b]Sent:[/b] Monday, February 6, 2017 5:02 PM [b]Subject:[/b] [mg-tabc] Brake Failure

 

Thanks to all of you for your ideas. I checked the brake lines,MC, etc with no indication of leakage. Then I bled the line out. Much air in there. The brakes came back after bleeding. Perhaps when I tested the brakes HARD the day before, I explosed some intermittent crack etc in the system which only shows up with hard use. I plan to give it a rigorous test after my diff comes back from being worked over. I'm on pins and needles driving it now and will try to break the fault during the next hard test. I'll keep the group informed. Thanks again. Jim Davis TC 7225 Houston

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