View Full Version : Anyone done a DOT5 conversion?
MyBlackBeasts
12-15-2012, 11:06 PM
Has anyone done a DOT5 brake fluid conversion to their MM?
fastblackmerc
12-16-2012, 09:11 AM
You'll need to make sure there is absolutely no old fluid left in the system. I believe you flush the system with denatured alcohol. Then you'll need the ABS pump cycled to get all the air out.
IMHO... too much work & cost for little gain.
Why the switch to DOT 5?
MyBlackBeasts
12-16-2012, 10:55 AM
You'll need to make sure there is absolutely no old fluid left in the system. I believe you flush the system with denatured alcohol. Then you'll need the ABS pump cycled to get all the air out.
IMHO... too much work & cost for little gain.
Why the switch to DOT 5?
Was considering the change when doing a big brake & SS line mod. The synthetic does not attract moisture, does not corode and I think would be a cheap protection of that kind of $$ investment.
The flush is easy enough and then with all the new parts I think it would be a good idea.
fastblackmerc
12-16-2012, 11:05 AM
Was considering the change when doing a big brake & SS line mod. The synthetic does not attract moisture, does not corode and I think would be a cheap protection of that kind of $$ investment.
The flush is easy enough and then with all the new parts I think it would be a good idea.
You might need a trip to a dealer to get the ABS pump cycled.
RubberCtyRauder
12-16-2012, 11:30 AM
Dot5 is also more compressable for lack of a better word. The brakes will feel spongier than they are now. Although tce brake line kit does help alot in that area
MyBlackBeasts
12-16-2012, 11:56 AM
Dot5 is also more compressable for lack of a better word. The brakes will feel spongier than they are now. Although tce brake line kit does help alot in that area
True but I believe with SS lines & big brakes it would not be noticible. IMO the Pro's far out-weigh the Con's.
MyBlackBeasts
12-16-2012, 12:01 PM
Brake Fluid DOT Grades
DOT3
DOT3 brake fluid is the "conventional" brake fluid used in most vehicles.
Advantages:
DOT3 fluid is inexpensive, and available at most gas stations, department stores, and any auto parts store.
Disadvantages:
DOT3 fluid eats paint!
DOT3 fluid absorbs water very readily. (This is often referred to as being hydroscopic.) As such, once a
container of DOT3 has been opened, it should not be stored for periods much longer than a week before use.
Since DOT3 fluid absorbs water, any moisture absorbed by the fluid can encourage corrosion in the brake lines
and cylinders.
DOT4
DOT4 brake fluid is the brake fluid suggested for use in some late model cars.
Advantages:
DOT4 fluid is available at most auto parts stores, and at some (but not all) gas stations or department stores.
DOT4 fluid does not absorb water as readily as DOT3 fluid.
DOT4 fluid has a higher boiling point than DOT3 fluid, making it more suitable for high performance applications
where the brake systems are expected to get hot.
Disadvantages:
DOT4 fluid eats paint! Small leaks around the master cylinder will eventually dissolve away the paint on your
bodywork in the general vicinity of the leak, and then give rust a chance to attack the body of your car!
DOT4 fluid is generally about 50% more expensive than DOT3 fluid.
Since DOT4 fluid still absorbs some water, any moisture absorbed by the fluid can encourage corrosion in the
brake lines and cylinders.
DOT5
DOT5 brake fluid is also known as "silicone" brake fluid.
Advantages:
DOT5 does not eat paint.
DOT5 does not absorb water and may be useful where water absorption is a problem.
DOT5 is compatible with all rubber formulations. (See more on this under disadvantages, below.)
Disadvantages:
DOT5 does NOT mix with DOT3, DOT4 or DOT5.1. Most reported problems with DOT5 are probably due to some
degree of mixing with other fluid types. The best way to convert to DOT5 is to totally rebuild the hydraulic
system.
Reports of DOT5 causing premature failure of rubber brake parts were more common with early DOT5
formulations. This is thought to be due to improper addition of swelling agents and has been fixed in recent
formulations.
Since DOT5 does not absorb water, any moisture in the hydraulic system will "puddle" in one place. This can
cause localized corrosion in the hydraulics.
Careful bleeding is required to get all of the air out of the system. Small bubbles can form in the fluid that will form
large bubbles over time. It may be necessary to do a series of bleeds.
DOT5 is slightly compressible (giving a very slightly soft pedal), and has a lower boiling point than DOT4.
DOT5 is about twice as expensive as DOT4 fluid. It is also difficult to find, generally only available at selected
auto parts stores.
DOT5.1
DOT5.1 is a relatively new brake fluid that is causing no end of confusion amongst mechanics. The DOT could avoid a
lot of confusion by giving this new fluid a different designation. The 5.1 designation could lead one to believe that it's a
modification of silicone-based DOT 5 brake fluid. Calling it 4.1 or 6 might have been more appropriate since it's a
glycol-based fluid like the DOT 3 and 4 types, not silicone-based like DOT 5 fluid.
As far as the basic behavior of 5.1 fluids, they are much like "high performance" DOT4 fluids, rather than traditional
DOT5 brake fluids.
Advantages:
DOT5.1 provides superior performance over the other brake fluids discussed here. It has a higher boiling point,
either dry or wet, than DOT 3 or 4. In fact, its dry boiling point (about 275 degrees C) is almost as high as racing
fluid (about 300 degrees C) and 5.1's wet boiling point (about 175 to 200 degrees C) is naturally much higher
than racing's (about 145 C).
DOT5.1 is said to be compatible with all rubber formulations.
Disadvantages: DOT5.1 fluids (and Spectro's Supreme DOT4) are non-silicone fluids and will absorb water.
DOT5.1 fluids, like DOT3 & DOT4 will eat paint.
DOT 5.1 fluids are difficult to find for sale, typically at very few auto parts stores, mostly limited to "speed shops."
DOT 5.1 will be more expensive than DOT3 or DOT4, and more difficult to find.
fastblackmerc
12-16-2012, 02:13 PM
Brake Fluid DOT Grades
DOT3
DOT3 brake fluid is the "conventional" brake fluid used in most vehicles.
Advantages:
DOT3 fluid is inexpensive, and available at most gas stations, department stores, and any auto parts store.
Disadvantages:
DOT3 fluid eats paint!
DOT3 fluid absorbs water very readily. (This is often referred to as being hydroscopic.) As such, once a
container of DOT3 has been opened, it should not be stored for periods much longer than a week before use.
Since DOT3 fluid absorbs water, any moisture absorbed by the fluid can encourage corrosion in the brake lines
and cylinders.
DOT4
DOT4 brake fluid is the brake fluid suggested for use in some late model cars.
Advantages:
DOT4 fluid is available at most auto parts stores, and at some (but not all) gas stations or department stores.
DOT4 fluid does not absorb water as readily as DOT3 fluid.
DOT4 fluid has a higher boiling point than DOT3 fluid, making it more suitable for high performance applications
where the brake systems are expected to get hot.
Disadvantages:
DOT4 fluid eats paint! Small leaks around the master cylinder will eventually dissolve away the paint on your
bodywork in the general vicinity of the leak, and then give rust a chance to attack the body of your car!
DOT4 fluid is generally about 50% more expensive than DOT3 fluid.
Since DOT4 fluid still absorbs some water, any moisture absorbed by the fluid can encourage corrosion in the
brake lines and cylinders.
DOT5
DOT5 brake fluid is also known as "silicone" brake fluid.
Advantages:
DOT5 does not eat paint.
DOT5 does not absorb water and may be useful where water absorption is a problem.
DOT5 is compatible with all rubber formulations. (See more on this under disadvantages, below.)
Disadvantages:
DOT5 does NOT mix with DOT3, DOT4 or DOT5.1. Most reported problems with DOT5 are probably due to some
degree of mixing with other fluid types. The best way to convert to DOT5 is to totally rebuild the hydraulic
system.
Reports of DOT5 causing premature failure of rubber brake parts were more common with early DOT5
formulations. This is thought to be due to improper addition of swelling agents and has been fixed in recent
formulations.
Since DOT5 does not absorb water, any moisture in the hydraulic system will "puddle" in one place. This can
cause localized corrosion in the hydraulics.
Careful bleeding is required to get all of the air out of the system. Small bubbles can form in the fluid that will form
large bubbles over time. It may be necessary to do a series of bleeds.
DOT5 is slightly compressible (giving a very slightly soft pedal), and has a lower boiling point than DOT4.
DOT5 is about twice as expensive as DOT4 fluid. It is also difficult to find, generally only available at selected
auto parts stores.
DOT5.1
DOT5.1 is a relatively new brake fluid that is causing no end of confusion amongst mechanics. The DOT could avoid a
lot of confusion by giving this new fluid a different designation. The 5.1 designation could lead one to believe that it's a
modification of silicone-based DOT 5 brake fluid. Calling it 4.1 or 6 might have been more appropriate since it's a
glycol-based fluid like the DOT 3 and 4 types, not silicone-based like DOT 5 fluid.
As far as the basic behavior of 5.1 fluids, they are much like "high performance" DOT4 fluids, rather than traditional
DOT5 brake fluids.
Advantages:
DOT5.1 provides superior performance over the other brake fluids discussed here. It has a higher boiling point,
either dry or wet, than DOT 3 or 4. In fact, its dry boiling point (about 275 degrees C) is almost as high as racing
fluid (about 300 degrees C) and 5.1's wet boiling point (about 175 to 200 degrees C) is naturally much higher
than racing's (about 145 C).
DOT5.1 is said to be compatible with all rubber formulations.
Disadvantages: DOT5.1 fluids (and Spectro's Supreme DOT4) are non-silicone fluids and will absorb water.
DOT5.1 fluids, like DOT3 & DOT4 will eat paint.
DOT 5.1 fluids are difficult to find for sale, typically at very few auto parts stores, mostly limited to "speed shops."
DOT 5.1 will be more expensive than DOT3 or DOT4, and more difficult to find.
The RED highlighted areas would be show stoppers for me.....
RoyLPita
12-17-2012, 01:47 PM
Dot4 ftw!!!!
Vortech347
12-18-2012, 02:35 PM
Motoblu. I run it when I open track.
Todd TCE
12-18-2012, 07:46 PM
Nice write up.
MyBlackBeasts
12-19-2012, 09:36 PM
Nice write up.
It is from TCCOA site.
MyBlackBeasts
12-19-2012, 10:07 PM
Motoblu. I run it when I open track.
What is Motoblu? Not familiar with it and Google finds no products by that name.
sailsmen
12-20-2012, 05:49 AM
All the cars I have owned plus those belonging to others, taken apart, put back together and not once has the brake fluid eaten the paint.
What am I doing wrong????:confused:
MyBlackBeasts
12-20-2012, 08:30 PM
All the cars I have owned plus those belonging to others, taken apart, put back together and not once has the brake fluid eaten the paint.
What am I doing wrong????:confused:
Oh, yes. Brake fluid left on the paint for a while = no paint & bare metal.
It actually is an easy & cheap way to strip paint off plastic trim pieces with out damaging the plastic.
sailsmen
12-20-2012, 09:23 PM
Apparently I managed to never get brake fluid on the paint?
MyBlackBeasts
12-20-2012, 09:39 PM
Apparently I managed to never get brake fluid on the paint?
Or you washed/wiped it off before it could lift the paint. Otherwise a couple days later you would have found a present! :eek:
JimmyXR7
12-24-2012, 07:01 AM
Or you washed/wiped it off before it could lift the paint. Otherwise a couple days later you would have found a present! :eek:
I know a friend put the brake fluid can on the driver side fender of his buick, as a ring of bare metal was showing.
I said "you added some brake fluid" "how did you know" "I laughed and pointed out the ring from the can."
If you think you could have spilled some, wash the fender.
My son changed the battery on my wife's car when I was at work. I had them wash the fender afterwards.
Cheap insurance against expensive paint damage.
Jim
MyBlackBeasts
12-24-2012, 07:30 AM
I know a friend put the brake fluid can on the driver side fender of his buick, as a ring of bare metal was showing.
I said "you added some brake fluid" "how did you know" "I laughed and pointed out the ring from the can."
If you think you could have spilled some, wash the fender.
My son changed the battery on my wife's car when I was at work. I had them wash the fender afterwards.
Cheap insurance against expensive paint damage.
Jim
Yep. Did this at work to prevent a bad customer experience. Mist-splash from a charging battery, corosion dust from the old one you are removing, brake fluid splash spots when doing a brakerepair, if left on paint = pissed off customer a few days later!!!
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