MadMaxx
Enthusiast
Changing out my brake fluid and clutch fluid this weekend. What fluid should I run? DOT 5.1 (not 5)?
thanks
James
thanks
James
Brake/Clutch fluid? DOT 5.1?
- Thread starter MadMaxx
- Start date
Bad_Byte
Enthusiast
I'm no expert but I don't think you want to touch the DOT 5 fluid in any form. As I understand its silicone based and will be a lot more trouble than you bargan for. Lots of issues with the DOT 5.
I think just stick with the Dot 4 most use the Motul I believe but there are many.
May I suggest doing a search.
good luck
I think just stick with the Dot 4 most use the Motul I believe but there are many.
May I suggest doing a search.
good luck
Chuck 98 RT/10
Enthusiast
DOT 4 unless you're going to track it.
In your brakes / clutch:
D0T 4 is OK.
DOT 5.1 is OK. Specifically 5.1.
Dot 5 is TABOO: "Silicone is for Breasts, not Brakes"
D0T 4 is OK.
DOT 5.1 is OK. Specifically 5.1.
Dot 5 is TABOO: "Silicone is for Breasts, not Brakes"
Tom and Vipers
Enthusiast
I'm starting to have second thoughts about silicone fluid.
First of all, if you live in the desert, moisture is not a problem with any fluid.
I had early DOW silicone fluid in a Studebaker for 25 years and never changed it.
I rebuilt the calipers and cylinders - they were not destroyed by rust although there was some rust damage.
I think that any other brake fluid would not have performed as well.
Of course, the early silicones had problems and that prejudiced everyone. I'll bet the latest formulations are OK.
Still controversial though....
First of all, if you live in the desert, moisture is not a problem with any fluid.
I had early DOW silicone fluid in a Studebaker for 25 years and never changed it.
I rebuilt the calipers and cylinders - they were not destroyed by rust although there was some rust damage.
I think that any other brake fluid would not have performed as well.
Of course, the early silicones had problems and that prejudiced everyone. I'll bet the latest formulations are OK.
Still controversial though....
Dot 5.1 boiling point is midway between Dot 4 and a good racing fluid. I would always use it in preference to Dot 4 (And its price is relatively low !)
Tom, the problem with silicone fluid is that it hangs on to air bubbles and is a devil to bleed and obtain a firm pedal. Here is an interesting discussion http://www.vtr.org/maintain/brake-fluids.html
Tom, the problem with silicone fluid is that it hangs on to air bubbles and is a devil to bleed and obtain a firm pedal. Here is an interesting discussion http://www.vtr.org/maintain/brake-fluids.html
Tom and Vipers
Enthusiast
Nice comparison Joel!
REGARDING DOT 5:
When making silicone rubber port casts, it is recommended that the mixture is placed under vacuum to pull the trapped air bubbles out.
While I have never done this, supposedly the mix will grow to twice its size, the bubbles come to the surface (they are 20 times as big now) and you get rid of them.
It would be interesting to see how this technique would work on silicone fluid!
I have done a lot of work on old cars - many that were sitting in fields. The rust damage I have seen in hydraulics is mind boggling! So I am always on the lookout for something that would solve this problem!
DOT 5 TIDBITS:
Rolls Royce voids warranty if DOT 5 used.
Harley uses DOT 5.
Military uses DOT 5.
REGARDING HYGROSCOPY:
Castrol LMA (Low Moisture Absorption) fluid sounds very interesting.
We need some kind of hygroscopy spec to compare fluids because this is the real culprit!
Of course, that would make selecting fluids too easy!
REGARDING DOT 5:
When making silicone rubber port casts, it is recommended that the mixture is placed under vacuum to pull the trapped air bubbles out.
While I have never done this, supposedly the mix will grow to twice its size, the bubbles come to the surface (they are 20 times as big now) and you get rid of them.
It would be interesting to see how this technique would work on silicone fluid!
I have done a lot of work on old cars - many that were sitting in fields. The rust damage I have seen in hydraulics is mind boggling! So I am always on the lookout for something that would solve this problem!
DOT 5 TIDBITS:
Rolls Royce voids warranty if DOT 5 used.
Harley uses DOT 5.
Military uses DOT 5.
REGARDING HYGROSCOPY:
Castrol LMA (Low Moisture Absorption) fluid sounds very interesting.
We need some kind of hygroscopy spec to compare fluids because this is the real culprit!
Of course, that would make selecting fluids too easy!
HP
Enthusiast
I'm always amused at the posts on phobias to Dot-5. Sure there
is the question on spongier pedal response, so maybe it would
not be the best fluid for the track. But looking at the
advantages, I just don't think it is given a fair shake for
the average driver. It's pretty much the standard for
high performance motorcycle applications, and their brake
technology has always been on the leading edge. For the average
Viper owner that doesn't bleed his brakes every season, I think
Dot-5 could be an alternative. Granted you do have to have a
good bleeding technique and flush your lines, but this is a
small price to pay for lifetime protection. Besides not
being hygroscopic, Dot-5 has none of the nasty solvent characteristic of the other 'Dots' - they will dissolve paint(even epoxy and polyurethane), undercoatings, many plastics,
and even linoleum and floor tile. They are the only solvents I
know of (other than paint remover) that will eat through
polyurethane paint and epoxy primer.
is the question on spongier pedal response, so maybe it would
not be the best fluid for the track. But looking at the
advantages, I just don't think it is given a fair shake for
the average driver. It's pretty much the standard for
high performance motorcycle applications, and their brake
technology has always been on the leading edge. For the average
Viper owner that doesn't bleed his brakes every season, I think
Dot-5 could be an alternative. Granted you do have to have a
good bleeding technique and flush your lines, but this is a
small price to pay for lifetime protection. Besides not
being hygroscopic, Dot-5 has none of the nasty solvent characteristic of the other 'Dots' - they will dissolve paint(even epoxy and polyurethane), undercoatings, many plastics,
and even linoleum and floor tile. They are the only solvents I
know of (other than paint remover) that will eat through
polyurethane paint and epoxy primer.
MadMaxx, Specifically use Motul 600 RBF. Should be about $10 per 500ml. I bought 3 and will be doing soon but I think you only need 1 or 2. I'll use extras in other cars. Buy pressure tank and adapter in service manual from Miller Tool.
