DOT Disk Brake Fluid vs Shimano mineral oil

One of the things that occurred to me while using these two different methods is that Shimano went through a great deal of trouble to study the bleeding system. Their mineral oil doesn't pick up dirt and water tends to float at the high point which is what gets bled off in their parts.

DOT on the other hand attracts dirt and seems to discolor from simply going through the hoses.

While the installation of the Avid Disks on the Felt required me to add length onto the lines what I did was to take the rear brake hose and use it on the front brake and then cutting it down to the proper length Since these lines were initially installed and bled by bike shop I only occasionally frequent I didn't know what they did or how. Yesterday I was looking at the one end left that they had installed and it has a Torx 10 fitting in it and what appears to be a tiny filter. Considering how discolored and sort of dirty the DOT fluid was I could understand why they would put a filter in the line rather than the standard push-in aluminum tube end that has to be hammered in. I can only assume that it is threaded and that you turn it in rather than hammer it in. So I won't mess with that end. Yesterday I pumped enough fluid through it that it finally started running clean. Tomorrow after some yard work I will try to bleed those brakes as carefully as possible.

One of the things they are pretty explicit about is that DOT fluid is a skin irritant and you must wear neoprene lab gloves. Well I always got brake fluid all over me and yesterday was no different. And I didn't notice any irritation. Of course I also washed afterwards. One of the things that the DOT does do it make everything slippery so you have to be careful to keep from dropping everything. And wearing rubber gloves doesn't make your manual dexterity magically better. I happened to buy Torx wrenches that are magnetic so it was pretty hard to drop and much easier to insert the port closures..

If I were to give any advice on disk brakes which I would not have on a road bike, it is to only use Shimano parts since their engineering skills of the components that are made in Japan (Dura Ace, Ultegra and 105) are pretty much above reproach. And you're unlikely to be irritated by the mineral oil unless you happen to be allergic to the red dye they mark it with so that you always know where the fluid is while you'd bleeding it.

You always have to remember to put the hose parts on in the correct order. Cover, Connector and then the bead that is a fluid seal. When this is all tightened down the bead is compressed and forms a fluid barrier. On the Shimano it didn't require a great deal of tightening but on the Avid it did or else it leaked.

On Tuesday, April 13, 2021 at 4:57:42 PM UTC-7, Tom Kunich wrote:
One of the things that occurred to me while using these two different methods is that Shimano went through a great deal of trouble to study the bleeding system. Their mineral oil doesn't pick up dirt and water tends to float at the high point which is what gets bled off in their parts.

DOT on the other hand attracts dirt and seems to discolor from simply going through the hoses.

While the installation of the Avid Disks on the Felt required me to add length onto the lines what I did was to take the rear brake hose and use it on the front brake and then cutting it down to the proper length Since these lines were initially installed and bled by bike shop I only occasionally frequent I didn't know what they did or how. Yesterday I was looking at the one end left that they had installed and it has a Torx 10 fitting in it and what appears to be a tiny filter. Considering how discolored and sort of dirty the DOT fluid was I could understand why they would put a filter in the line rather than the standard push-in aluminum tube end that has to be hammered in. I can only assume that it is threaded and that you turn it in rather than hammer it in. So I won't mess with that end. Yesterday I pumped enough fluid through it that it finally started running clean. Tomorrow after some yard work I will try to bleed those brakes as carefully as possible..

One of the things they are pretty explicit about is that DOT fluid is a skin irritant and you must wear neoprene lab gloves. Well I always got brake fluid all over me and yesterday was no different. And I didn't notice any irritation. Of course I also washed afterwards. One of the things that the DOT does do it make everything slippery so you have to be careful to keep from dropping everything. And wearing rubber gloves doesn't make your manual dexterity magically better. I happened to buy Torx wrenches that are magnetic so it was pretty hard to drop and much easier to insert the port closures.

If I were to give any advice on disk brakes which I would not have on a road bike, it is to only use Shimano parts since their engineering skills of the components that are made in Japan (Dura Ace, Ultegra and 105) are pretty much above reproach. And you're unlikely to be irritated by the mineral oil unless you happen to be allergic to the red dye they mark it with so that you always know where the fluid is while you'd bleeding it.

You always have to remember to put the hose parts on in the correct order.. Cover, Connector and then the bead that is a fluid seal. When this is all tightened down the bead is compressed and forms a fluid barrier. On the Shimano it didn't require a great deal of tightening but on the Avid it did or else it leaked.
Since I am building a gravel bike with a flat bar I guess I should add that Deore XT and XTR would be a better selection than anything from Avid or SRAM. Once bitten twice shy.

On Wednesday, April 14, 2021 at 8:45:56 AM UTC-7, wrote:
On Tuesday, April 13, 2021 at 4:57:42 PM UTC-7, Tom Kunich wrote:
One of the things that occurred to me while using these two different methods is that Shimano went through a great deal of trouble to study the bleeding system. Their mineral oil doesn't pick up dirt and water tends to float at the high point which is what gets bled off in their parts.

DOT on the other hand attracts dirt and seems to discolor from simply going through the hoses.

While the installation of the Avid Disks on the Felt required me to add length onto the lines what I did was to take the rear brake hose and use it on the front brake and then cutting it down to the proper length Since these lines were initially installed and bled by bike shop I only occasionally frequent I didn't know what they did or how. Yesterday I was looking at the one end left that they had installed and it has a Torx 10 fitting in it and what appears to be a tiny filter. Considering how discolored and sort of dirty the DOT fluid was I could understand why they would put a filter in the line rather than the standard push-in aluminum tube end that has to be hammered in. I can only assume that it is threaded and that you turn it in rather than hammer it in. So I won't mess with that end. Yesterday I pumped enough fluid through it that it finally started running clean. Tomorrow after some yard work I will try to bleed those brakes as carefully as possible.

One of the things they are pretty explicit about is that DOT fluid is a skin irritant and you must wear neoprene lab gloves. Well I always got brake fluid all over me and yesterday was no different. And I didn't notice any irritation. Of course I also washed afterwards. One of the things that the DOT does do it make everything slippery so you have to be careful to keep from dropping everything. And wearing rubber gloves doesn't make your manual dexterity magically better. I happened to buy Torx wrenches that are magnetic so it was pretty hard to drop and much easier to insert the port closures.

If I were to give any advice on disk brakes which I would not have on a road bike, it is to only use Shimano parts since their engineering skills of the components that are made in Japan (Dura Ace, Ultegra and 105) are pretty much above reproach. And you're unlikely to be irritated by the mineral oil unless you happen to be allergic to the red dye they mark it with so that you always know where the fluid is while you'd bleeding it.

You always have to remember to put the hose parts on in the correct order. Cover, Connector and then the bead that is a fluid seal. When this is all tightened down the bead is compressed and forms a fluid barrier. On the Shimano it didn't require a great deal of tightening but on the Avid it did or else it leaked.
Since I am building a gravel bike with a flat bar I guess I should add that Deore XT and XTR would be a better selection than anything from Avid or SRAM. Once bitten twice shy.

Are you still building that bike? Its a bike, not the pyramids. And yes, assembling the (and note the correct terms) barb, olive and compression nut does take a Fisher Price toy level of intelligence to assemble, and in fact, how can you even put them on in the wrong order? Putting the olive on before the compression nut wouldn't even work.

-- Jay Beattie.

On Wednesday, April 14, 2021 at 10:40:10 AM UTC-7, jbeattie wrote:
On Wednesday, April 14, 2021 at 8:45:56 AM UTC-7, wrote:
On Tuesday, April 13, 2021 at 4:57:42 PM UTC-7, Tom Kunich wrote:
One of the things that occurred to me while using these two different methods is that Shimano went through a great deal of trouble to study the bleeding system. Their mineral oil doesn't pick up dirt and water tends to float at the high point which is what gets bled off in their parts.

DOT on the other hand attracts dirt and seems to discolor from simply going through the hoses.

While the installation of the Avid Disks on the Felt required me to add length onto the lines what I did was to take the rear brake hose and use it on the front brake and then cutting it down to the proper length Since these lines were initially installed and bled by bike shop I only occasionally frequent I didn't know what they did or how. Yesterday I was looking at the one end left that they had installed and it has a Torx 10 fitting in it and what appears to be a tiny filter. Considering how discolored and sort of dirty the DOT fluid was I could understand why they would put a filter in the line rather than the standard push-in aluminum tube end that has to be hammered in. I can only assume that it is threaded and that you turn it in rather than hammer it in. So I won't mess with that end. Yesterday I pumped enough fluid through it that it finally started running clean. Tomorrow after some yard work I will try to bleed those brakes as carefully as possible.

One of the things they are pretty explicit about is that DOT fluid is a skin irritant and you must wear neoprene lab gloves. Well I always got brake fluid all over me and yesterday was no different. And I didn't notice any irritation. Of course I also washed afterwards. One of the things that the DOT does do it make everything slippery so you have to be careful to keep from dropping everything. And wearing rubber gloves doesn't make your manual dexterity magically better. I happened to buy Torx wrenches that are magnetic so it was pretty hard to drop and much easier to insert the port closures.

If I were to give any advice on disk brakes which I would not have on a road bike, it is to only use Shimano parts since their engineering skills of the components that are made in Japan (Dura Ace, Ultegra and 105) are pretty much above reproach. And you're unlikely to be irritated by the mineral oil unless you happen to be allergic to the red dye they mark it with so that you always know where the fluid is while you'd bleeding it.

You always have to remember to put the hose parts on in the correct order. Cover, Connector and then the bead that is a fluid seal. When this is all tightened down the bead is compressed and forms a fluid barrier. On the Shimano it didn't require a great deal of tightening but on the Avid it did or else it leaked.
Since I am building a gravel bike with a flat bar I guess I should add that Deore XT and XTR would be a better selection than anything from Avid or SRAM. Once bitten twice shy.
Are you still building that bike? Its a bike, not the pyramids. And yes, assembling the (and note the correct terms) barb, olive and compression nut does take a Fisher Price toy level of intelligence to assemble, and in fact, how can you even put them on in the wrong order? Putting the olive on before the compression nut wouldn't even work.

Tell me Jay, are you so excited to buy that bike from me that you can't wait until it is finished? Or are you saying that I should hurry up so that you can read my report on what a great bike those Felt Gravel bikes are?

On Thursday, April 15, 2021 at 8:41:45 AM UTC-7, wrote:
On Wednesday, April 14, 2021 at 10:40:10 AM UTC-7, jbeattie wrote:
On Wednesday, April 14, 2021 at 8:45:56 AM UTC-7, wrote:
On Tuesday, April 13, 2021 at 4:57:42 PM UTC-7, Tom Kunich wrote:
One of the things that occurred to me while using these two different methods is that Shimano went through a great deal of trouble to study the bleeding system. Their mineral oil doesn't pick up dirt and water tends to float at the high point which is what gets bled off in their parts.

DOT on the other hand attracts dirt and seems to discolor from simply going through the hoses.

While the installation of the Avid Disks on the Felt required me to add length onto the lines what I did was to take the rear brake hose and use it on the front brake and then cutting it down to the proper length Since these lines were initially installed and bled by bike shop I only occasionally frequent I didn't know what they did or how. Yesterday I was looking at the one end left that they had installed and it has a Torx 10 fitting in it and what appears to be a tiny filter. Considering how discolored and sort of dirty the DOT fluid was I could understand why they would put a filter in the line rather than the standard push-in aluminum tube end that has to be hammered in. I can only assume that it is threaded and that you turn it in rather than hammer it in. So I won't mess with that end. Yesterday I pumped enough fluid through it that it finally started running clean. Tomorrow after some yard work I will try to bleed those brakes as carefully as possible.

One of the things they are pretty explicit about is that DOT fluid is a skin irritant and you must wear neoprene lab gloves. Well I always got brake fluid all over me and yesterday was no different. And I didn't notice any irritation. Of course I also washed afterwards. One of the things that the DOT does do it make everything slippery so you have to be careful to keep from dropping everything. And wearing rubber gloves doesn't make your manual dexterity magically better. I happened to buy Torx wrenches that are magnetic so it was pretty hard to drop and much easier to insert the port closures.

If I were to give any advice on disk brakes which I would not have on a road bike, it is to only use Shimano parts since their engineering skills of the components that are made in Japan (Dura Ace, Ultegra and 105) are pretty much above reproach. And you're unlikely to be irritated by the mineral oil unless you happen to be allergic to the red dye they mark it with so that you always know where the fluid is while you'd bleeding it.

You always have to remember to put the hose parts on in the correct order. Cover, Connector and then the bead that is a fluid seal. When this is all tightened down the bead is compressed and forms a fluid barrier. On the Shimano it didn't require a great deal of tightening but on the Avid it did or else it leaked.
Since I am building a gravel bike with a flat bar I guess I should add that Deore XT and XTR would be a better selection than anything from Avid or SRAM. Once bitten twice shy.
Are you still building that bike? Its a bike, not the pyramids. And yes, assembling the (and note the correct terms) barb, olive and compression nut does take a Fisher Price toy level of intelligence to assemble, and in fact, how can you even put them on in the wrong order? Putting the olive on before the compression nut wouldn't even work.

Tell me Jay, are you so excited to buy that bike from me that you can't wait until it is finished? Or are you saying that I should hurry up so that you can read my report on what a great bike those Felt Gravel bikes are?

You have a Felt CX bike. I have a great gravel bike that, unfortunately, hasn't seen much gravel this year. https://static.westernbikeworks.com/...0/nzcyr1-1.jpg Velo News liked the Ultegra version. https://www.velonews.com/gear/gravel...el-bikes-year/

I last used that bike for snow riding around the pioneer cemetery with my knobby CX tires. https://photos.app.goo.gl/RtaZgubTTwcAKZBu8 I just put some road pedals on it and Roval C38s for my son's visit. It is his Portland road bike.

That bike with 105 was sub $1600 brand new from Western Bikeworks -- super sale. Trek also has the Checkpoint aluminum in the $1600 range. https://www.trekbikes.com/us/en_US/b...orCode=reddark Your aluminum Felt CX bike with Avid brakes will have to come in way below that.

-- Jay Beattie.