Speedzilla Forums banner

1 - 17 of 17 Posts
G

·
Guest
Joined
·
0 Posts
Discussion Starter #1
so i was thinking about using this for my clutch and brakes. need to flush and re bleed for this year for my 998 especially my rear brake that sucks but then i dont use it anyway. so what does everyone think of 5.1. will it do any harm to my brake system? is it safe to use seals etc...............
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #2
Re: motul 5.1 brake fluid (killer bee)

5.1 is totally compatible with Dot 3 or 4 but definitely not 5. I recently did my brake/clutch fluid flush and replacement using Motul 5.1 with no problems.
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #3
Re: motul 5.1 brake fluid (TnDuc)

Been using 5.1 for a couple of years. Good stuff! High boiling point and compatible with DOT 3 and 4.
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #4
Re: motul 5.1 brake fluid (killer bee)

This recently came over the M.A.D. list...I start prepping my bike next weekend and I might have a go at this...

I have recently discovered a brake fluid that I believe will reduce the frequency of changing the fluid. as i mentioned, i tried a bunch of different brake fluids last year and the max i got was 3 days. the worst (Honda racing fluid) only worked for a day! A couple of very well known endurance teams are using Porsche Super Blue racing fluid. A bud of mine who races expert and is a fast CR (33's at VIR N) used this last year and only needed to change 4 times.
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #5
Re: motul 5.1 brake fluid (killer bee)

You will have to change 5.1 more often. Find the highest dry and wet boiling points and compromise. In some cases you will find Dot 4 fluid with higher wet boiling points then Dot 5.1.

Depends on how you ride and will maintenance your system.

If you are a racer and have a regular maintenance program you want the highest dry boiling point and not really care what the wet is because you are changing the fluid often.

If you are a road rider and change your brake fluid once a year or less you will want a higher wet boiling point as your brake fluid is hydroscopic and will take on h20 over time.

And never keep old brake fluid - it is absorbing moisture just like your brake system.
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #6
Re: motul 5.1 brake fluid (22350DK)

thanks for the good info guys
this message board rocks
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #7
Re: motul 5.1 brake fluid (killer bee)

Dont take this as the last word on brake fluid but I think this should cover 90% of it.



DOT3 brake fluid is the "conventional" brake fluid used in most vehicles. One of the most familiar brands is "Prestone."

Advantages:

DOT3 fluid is inexpensive, and available at most gas stations, department stores, and any auto parts store.

Disadvantages:

DOT3 will damage natural rubber brake seals and should not be used in any vehicle suspected of having natural rubber seals

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 late model vehicles.
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.

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 doesn't 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 or DOT4. 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 doesnt absorb any 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 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.

General Recommendations:
If you have a brake system that doesn't leak or show any other signs of failure, but has old seals in it, don't change fluid types as a result of reading this article. If it isn't broken, don't "fix" it -- you may simply break it instead!
Flushing of the brake system every couple years to remove any absorbed or collected water is probably a good idea to prevent corrosion,regardless of the type of brake fluid used.

DOT3 is dangerous to use in vehicles with natural rubber seals., except as a temporary "quick fix to get me home" solution. (If this is used as a "get-me-home" solution, bleed the system as soon as possible, and be prepared to replace all yourseals.) DOT3 is an adequate brake fluid for use in later vehicles.

DOT4 fluid, for a slight increase in cost, will give significantly increased resistance to moisture absorption, thus decreasing the likelihood of corrosion compared to DOT3. DOT4 fluid has a higher boiling point than DOT3, making it preferable for high performance uses such as racing, autocross, or excessive use of the brakes in mountainous areas. For even greater braking performance, consider going to DOT5.1 or a high-performance version of DOT4 fluid.


DOT5is a good choice for the weekend driver. It doesn't absorb water and it doesn't eat paint. One caveat is that because it doesn't absorb water, water that gets in the system will tend to collect at low points. In this scenario, it would actually be promoting corrosion.



When changing from one fluid type to another, as a minimum, bleed all of the old fluid out of the system completely. For best results, all the seals in the system should be replaced.



As always, your experiences may vary.
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #8
Re: motul 5.1 brake fluid (killer bee)

DOT5.1 provides superior performance over the other brake fluids discussed here. It has a higher boiling point said:
As I mentioned above there are Dot 4 fluids that are superior to Dot 5.1 fluids in the wet category which would mean that 5.1 is not the superior fluid when looking at the big picture.
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #9
Re: motul 5.1 brake fluid (22350DK)

Maybe if you are talking about specialty DOT4 brake fluids but for the most part the info I posted is correct
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #10
Re: motul 5.1 brake fluid (Ducman851)

I use DOT 5.1 now, due to my elite mechanic (!) and I approve. I can stop so hard, it brings back memmories of last week. Anyhow, it works well and I'm as happy as can be, maybe even happier...
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #11
Re: motul 5.1 brake fluid (996miami)

CASTROL SRF!


Dry boiling point: 590F/310C
Wet boiling point: 518F/270C
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #13
Re: motul 5.1 brake fluid (Phil 998)

Good Choice.



Castrol SRF is the best, hard to find, four-times more expensive than the others, and used by every Formula 1 team in existance because it’s boiling point drops very little as it absorbs moisture.

Motul RBF 600 is next best and reasonably priced. Same dry boiling point and the next-highest wet boiling point. Still, any fresh dry fluid will be better than wet Motul because of a still higher boiling point.

ATE Super Blue and Type 200 and are the same fluid. The theory is to alternate them and you can tell from the color when you have flushed all the old fluid out. In practice however, once a can is opened it should be used-up quickly. It’s not a good idea to save fluid from an opened can for color change reasons.
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #14
Re: motul 5.1 brake fluid (Shazaam!)

Maybe I'm just lucky, Castrol SRF is not at all hard to get hold of on this side of the pond.

Certainly not cheap though - deep breath, retails at £42.95 GBP per litre which at todays exchange rate is approx $82.00 US per litre! It is good though!
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #15
Re: motul 5.1 brake fluid (Shazaam!)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Shazaam! »</TD></TR><TR><TD CLASS="quote">
ATE Super Blue and Type 200 and are the same fluid. The theory is to alternate them and you can tell from the color when you have flushed all the old fluid out. In practice however, once a can is opened it should be used-up quickly. It’s not a good idea to save fluid from an opened can for color change reasons.</TD></TR></TABLE>.

but its so cheap its easier to just buy new each season. Its like $11 a liter. i buy a new liter each summer and I end up doing several friends brakes with it just because I cant use it all before I need to toss it. Its treated me quite well.
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #16
Re: motul 5.1 brake fluid (Vcook)

I have used both the Motul 5.1 and 600rbf. I switched back to the 600rbf because my all of my racing buddies use it and we kill a bottle at the same time. That way it is always fresh!!!

I found no difference regarding braking with either fluid.
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #17
Re: motul 5.1 brake fluid (rugbymook)

I didn't mean to imply there was a difference in braking with new fluid. Motul 5.1 is used because the new rotors, Brembo goldlines and master cylinder/lever. Those three (5 pcs) hardware changes alone are simply amazing for braking quality, both modulating braking and less or zero brade fade.
 
1 - 17 of 17 Posts
Top