In a recent thread, we were discussing brake glazing and I was surprised to see that the term was not widely understood or defined so I looked it up. Here's what I found:What causes brake pad glazing?Brake pad glazing is caused when the brake pad friction material is overheated. This results in crystallized friction material on the pad surface and the brake disc. Typical symptoms of glazed brake pads include: Poor stopping performance, vibration or brake judder, and cracks or fissures in the brake pad material. Pad glazing is typically caused by operating the brake pads at a temperature above the specified temperature range of the friction material or not properly following the 'Bedding-in' instructions for the brake pads. Always follow the manufacturers brake pad bedding-in instructions and use a brake pad that has a temperature range that is sufficient for its intended use.What can happen to my brake pads if not bedded properly?Proper break-in will assure that small amounts of heat are introduced to the brake pad. Brake pads that are brought up to temperature too fast and not properly allowed to cool down may quickly become glazed and not perform as originally intended. The pad’s rubbing surface reaches extreme heat levels during racing use. The surface needs slow temperature increases to help prepare the pad. Large amounts of heat all at one time can cause the brake pad rubbing surface to become somewhat liquified and coat the pad surface with a glaze. This will dramatically reduce stopping performance as certain ingredients in the friction compound breakdown and cause glazing of the rubbing surface of the brake pad.First off, does everyone agree with the above text? If so, then what's the best way to prevent glazing while driving a motorhome? For example, would constant use of the Jake brake help the situation? Do we need to bed in our brakes when we get a new MH? Finally, does the rotor / drum glaze differently from the brake pads? Or is it the same thing?

holstein13 wrote:In a recent thread, we were discussing brake glazing and I was surprised to see that the term was not widely understood or defined so I looked it up. Here's what I found:What causes brake pad glazing?Brake pad glazing is caused when the brake pad friction material is overheated. This results in crystallized friction material on the pad surface and the brake disc. Typical symptoms of glazed brake pads include: Poor stopping performance, vibration or brake judder, and cracks or fissures in the brake pad material. Pad glazing is typically caused by operating the brake pads at a temperature above the specified temperature range of the friction material or not properly following the 'Bedding-in' instructions for the brake pads. Always follow the manufacturers brake pad bedding-in instructions and use a brake pad that has a temperature range that is sufficient for its intended use.What can happen to my brake pads if not bedded properly?Proper break-in will assure that small amounts of heat are introduced to the brake pad. Brake pads that are brought up to temperature too fast and not properly allowed to cool down may quickly become glazed and not perform as originally intended. The pad’s rubbing surface reaches extreme heat levels during racing use. The surface needs slow temperature increases to help prepare the pad. Large amounts of heat all at one time can cause the brake pad rubbing surface to become somewhat liquified and coat the pad surface with a glaze. This will dramatically reduce stopping performance as certain ingredients in the friction compound breakdown and cause glazing of the rubbing surface of the brake pad.First off, does everyone agree with the above text? If so, then what's the best way to prevent glazing while driving a motorhome? For example, would constant use of the Jake brake help the situation? Do we need to bed in our brakes when we get a new MH? Finally, does the rotor / drum glaze differently from the brake pads? Or is it the same thing?Wiki

Busskipper wrote:WikiThanks Busskipper, I read the entire article and found it extremely lacking. In fact, there was NO definition of what glazing actually is other than it results in a shiny pad or shoe. Pretty much useless. In fact, there were contradictions in the article referring to gasses that may be produced in the pad or shoe affecting braking. I'm shocked how little information is available online with regards to this subject.When I do an image search for "brake glazing" Google shows a lot of rotors as well as brake pads. No pictures of drum shoes (not that I have drum brakes, however). It's very confusing and frustrating.My current understanding of glazing is that it only affects the pads or shoes, not the rotors or drums.Does anyone really understand this subject?

When the brake pad material, that has overheated and glazed, gets deposited on the rotor, it makes the rotor look like it is glazed. This can usually be removed from the rotor by turning them. Pad glazing occurs whenever the pads are overheated. This can be because the wrong pad material was used for the brakes on a certain vehicle. OEM pad material is usually the best choice and will dissipate heat better than some ceramic pads which may transfer more heat to the rotors. Basically all of the same thing apply to shoes and drums. Drum brakes were still used on some vehicles. My Chevy HHR toad has drum brakes on the rear.

holstein13 wrote:Busskipper wrote:WikiThanks Busskipper, I read the entire article and found it extremely lacking. In fact, there was NO definition of what glazing actually is other than it results in a shiny pad or shoe. Pretty much useless. In fact, there were contradictions in the article referring to gasses that may be produced in the pad or shoe affecting braking. I'm shocked how little information is available online with regards to this subject.When I do an image search for "brake glazing" Google shows a lot of rotors as well as brake pads. No pictures of drum shoes (not that I have drum brakes, however). It's very confusing and frustrating.My current understanding of glazing is that it only affects the pads or shoes, not the rotors or drums.Does anyone really understand this subject?My understanding has always been that brake glazing in a Motorhome application is due to being too light on the brakes...too much dependence upon the Pac or Jake brake and very little full engagement of the service brakes.Also many are unaware that they need to calibrate their automatic slack adjusters periodically to insure that the brakes can be engaged fully.

holstein13 wrote:Busskipper wrote:WikiThanks Busskipper, I read the entire article and found it extremely lacking. In fact, there was NO definition of what glazing actually is other than it results in a shiny pad or shoe. Pretty much useless. In fact, there were contradictions in the article referring to gasses that may be produced in the pad or shoe affecting braking. I'm shocked how little information is available online with regards to this subject.When I do an image search for "brake glazing" Google shows a lot of rotors as well as brake pads. No pictures of drum shoes (not that I have drum brakes, however). It's very confusing and frustrating.My current understanding of glazing is that it only affects the pads or shoes, not the rotors or drums.Does anyone really understand this subject?In my experience - owning a company with a large number (50-100) of trucks on the road - Glazing as I define it was caused from driving with an excess of usage of the brakes for extended periods. Like, putting your foot on the brake as you descend from Eisenhower tunnel into Denver, never giving the brakes a chance to cool, never taking your foot off he brake. The brakes and the Rotor/drum will overheat and "glaze" become shiny and have a reduced ability to brake - so the Glazing comes from continuous overuse and overheating the brakes. Again from my experience, I have replaced many a Drum or Rotor that is just not functioning correctly because of the heat apparently glazing the surface of the metal and not being able to stop, properly. Hence the reason most larger trucks have engine or transmission braking.IMHO most DP have more than enough braking to stop the coach, so the manufacturer has done his part now the RV driver, if he is having an "Issue" with driving then I usually suggest that they just Slow Down, and avoid the roads that provide the Issue, they feel better and I feel better.So for me the question is not glazing, but does the Coach feel safe and stop when it should? If not, then we need to check the brakes and maybe the driver.Hope this helps,

What is brake glazing? How do you prevent it? | Good Sam Community

holstein13
Explorer
Aug 16, 2015
Busskipper wrote:
In my experience - owning a company with a large number (50-100) of trucks on the road - Glazing as I define it was caused from driving with an excess of usage of the brakes for extended periods. Like, putting your foot on the brake as you descend from Eisenhower tunnel into Denver, never giving the brakes a chance to cool, never taking your foot off he brake. The brakes and the Rotor/drum will overheat and "glaze" become shiny and have a reduced ability to brake - so the Glazing comes from continuous overuse and overheating the brakes. Again from my experience, I have replaced many a Drum or Rotor that is just not functioning correctly because of the heat apparently glazing the surface of the metal and not being able to stop, properly. Hence the reason most larger trucks have engine or transmission braking.

IMHO most DP have more than enough braking to stop the coach, so the manufacturer has done his part now the RV driver, if he is having an "Issue" with driving then I usually suggest that they just Slow Down, and avoid the roads that provide the Issue, they feel better and I feel better.

So for me the question is not glazing, but does the Coach feel safe and stop when it should?

If not, then we need to check the brakes and maybe the driver.

Hope this helps,
Yes, it does. I'm beginning to believe that the best way to approach mountain driving is to minimize the overheating of the brakes. I'm projecting that the two best ways to do this would be 1) use the Jake Brake wherever heaving braking is needed and, frankly, use it everywhere. No reason not to. and 2) If you have to use the service brakes, use them for short bursts while allowing the brakes to cool between uses.

Would you agree with this? It's the exact opposite response from what Formerboater wrote above. But I think formerboater is reflecting the commonly held beliefs of our RV community.

BTW, my brakes are great. I love the way my coach stops with six large disc brakes. The mechanic who inspected it said they were in great shape.
Busskipper
Explorer
Aug 16, 2015
holstein13 wrote:
Busskipper wrote:
Wiki
Thanks Busskipper, I read the entire article and found it extremely lacking. In fact, there was NO definition of what glazing actually is other than it results in a shiny pad or shoe. Pretty much useless. In fact, there were contradictions in the article referring to gasses that may be produced in the pad or shoe affecting braking.

I'm shocked how little information is available online with regards to this subject.

When I do an image search for "brake glazing" Google shows a lot of rotors as well as brake pads. No pictures of drum shoes (not that I have drum brakes, however). It's very confusing and frustrating.

My current understanding of glazing is that it only affects the pads or shoes, not the rotors or drums.

Does anyone really understand this subject?

In my experience - owning a company with a large number (50-100) of trucks on the road - Glazing as I define it was caused from driving with an excess of usage of the brakes for extended periods. Like, putting your foot on the brake as you descend from Eisenhower tunnel into Denver, never giving the brakes a chance to cool, never taking your foot off he brake. The brakes and the Rotor/drum will overheat and "glaze" become shiny and have a reduced ability to brake - so the Glazing comes from continuous overuse and overheating the brakes. Again from my experience, I have replaced many a Drum or Rotor that is just not functioning correctly because of the heat apparently glazing the surface of the metal and not being able to stop, properly. Hence the reason most larger trucks have engine or transmission braking.

IMHO most DP have more than enough braking to stop the coach, so the manufacturer has done his part now the RV driver, if he is having an "Issue" with driving then I usually suggest that they just Slow Down, and avoid the roads that provide the Issue, they feel better and I feel better.

So for me the question is not glazing, but does the Coach feel safe and stop when it should?

If not, then we need to check the brakes and maybe the driver.

Hope this helps,
FormerBoater
Explorer
Aug 16, 2015
holstein13 wrote:
Busskipper wrote:
Wiki
Thanks Busskipper, I read the entire article and found it extremely lacking. In fact, there was NO definition of what glazing actually is other than it results in a shiny pad or shoe. Pretty much useless. In fact, there were contradictions in the article referring to gasses that may be produced in the pad or shoe affecting braking.

I'm shocked how little information is available online with regards to this subject.

When I do an image search for "brake glazing" Google shows a lot of rotors as well as brake pads. No pictures of drum shoes (not that I have drum brakes, however). It's very confusing and frustrating.

My current understanding of glazing is that it only affects the pads or shoes, not the rotors or drums.

Does anyone really understand this subject?

My understanding has always been that brake glazing in a Motorhome application is due to being too light on the brakes...too much dependence upon the Pac or Jake brake and very little full engagement of the service brakes.

Also many are unaware that they need to calibrate their automatic slack adjusters periodically to insure that the brakes can be engaged fully.
rgatijnet1
Explorer III
Aug 16, 2015
When the brake pad material, that has overheated and glazed, gets deposited on the rotor, it makes the rotor look like it is glazed. This can usually be removed from the rotor by turning them.
Pad glazing occurs whenever the pads are overheated. This can be because the wrong pad material was used for the brakes on a certain vehicle. OEM pad material is usually the best choice and will dissipate heat better than some ceramic pads which may transfer more heat to the rotors. Basically all of the same thing apply to shoes and drums. Drum brakes were still used on some vehicles. My Chevy HHR toad has drum brakes on the rear.
holstein13
Explorer
Aug 16, 2015
Busskipper wrote:
Wiki
Thanks Busskipper, I read the entire article and found it extremely lacking. In fact, there was NO definition of what glazing actually is other than it results in a shiny pad or shoe. Pretty much useless. In fact, there were contradictions in the article referring to gasses that may be produced in the pad or shoe affecting braking.

I'm shocked how little information is available online with regards to this subject.

When I do an image search for "brake glazing" Google shows a lot of rotors as well as brake pads. No pictures of drum shoes (not that I have drum brakes, however). It's very confusing and frustrating.

My current understanding of glazing is that it only affects the pads or shoes, not the rotors or drums.

Does anyone really understand this subject?
Busskipper
Explorer
Aug 16, 2015
holstein13 wrote:
In a recent thread, we were discussing brake glazing and I was surprised to see that the term was not widely understood or defined so I looked it up. Here's what I found:

What causes brake pad glazing?
Brake pad glazing is caused when the brake pad friction material is overheated. This results in crystallized friction material on the pad surface and the brake disc. Typical symptoms of glazed brake pads include: Poor stopping performance, vibration or brake judder, and cracks or fissures in the brake pad material. Pad glazing is typically caused by operating the brake pads at a temperature above the specified temperature range of the friction material or not properly following the 'Bedding-in' instructions for the brake pads. Always follow the manufacturers brake pad bedding-in instructions and use a brake pad that has a temperature range that is sufficient for its intended use.

What can happen to my brake pads if not bedded properly?
Proper break-in will assure that small amounts of heat are introduced to the brake pad. Brake pads that are brought up to temperature too fast and not properly allowed to cool down may quickly become glazed and not perform as originally intended. The pad’s rubbing surface reaches extreme heat levels during racing use. The surface needs slow temperature increases to help prepare the pad. Large amounts of heat all at one time can cause the brake pad rubbing surface to become somewhat liquified and coat the pad surface with a glaze. This will dramatically reduce stopping performance as certain ingredients in the friction compound breakdown and cause glazing of the rubbing surface of the brake pad.

First off, does everyone agree with the above text? If so, then what's the best way to prevent glazing while driving a motorhome? For example, would constant use of the Jake brake help the situation? Do we need to bed in our brakes when we get a new MH? Finally, does the rotor / drum glaze differently from the brake pads? Or is it the same thing?

Wiki

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What is brake glazing? How do you prevent it?

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