I know some cars should probably not convert to synthetic oil, but what about synthetic brake fluid?
DOT 5.1 is fine, but do not use DOT 5 or silicone. Castrol LMA is a good street brake fluid and it is DOT 3/4. Taz Terry Phillips
I think most Dot 3 or 4 Synthetic brakes fluids are fine. Do not use Silicone Dot5 without consulting with your mechanic. About the only vehicles using Dot 5 Silicone are Harley Davidsons.
DOT 3 & 4 absorb water thats why We change the fluid often. The silicon (dot 5) does not absorb water which initially sounds lika a good thing but the water collects in low spots in the lines and begins to rust from the inside out
Thats not the worst part. Where is the low spot? The brake caliper, thats where. You have just traded brake fluid with a 400-500 degree boiling point for a fluid with a boiling point of 212. Sounds like a great idea huh? Such a good idea the TUV (Germany's DOT) DOES NOT ALLOW IT. It was invented by Dow Chemical and if not for their political pull it would not have been approved for use here either.
At Kragen I have bought synthetic brake fluid (major oil company, forgot which). It is not DOT 5, silicone fluid. It is DOT 3 and 4, looks like regular brake fluid, mixes with regular DOT 3 or 4, can be used interchangably
I periodically encounter anecdotal DOT 5 prejudice and condemnation such as has been offered here on the various auto hobby web sites that I visit. I have no interest whatsoever in getting into yet another useless internet debate on this subject, trying in vain to convince those who have never used this fluid and whose minds are already firmly made up on this topic. Rather, I will simply relate here my own personal first-hand experiences with silicone DOT 5 as my one, and only, single posting on this subject, and I will leave it at that. The reader will thus be left free to reach their own conclusions. I am a big fan of DOT 5 silicone brake fluid. I have long ago swapped over to it from the OEM DOT 3 fluid in all of my hobby cars, including my 308. I value the long term advantages of DOT 5 in terms of permanence, and I have been using this fluid, specifically in my 308, for about 5 years now, with no problems whatsoever noted. For a number of years I have taken my 308 to Mid-Ohio, the well-known IndyCar track, for the local Ferrari Club Track Lap Days. Mid-Ohio has a long straightaway with a sharp 90 degree right downhill turn at the end. I approach this turn at 110 ~ 120 mph, and have to brake HARD, down to about 50 ~ 60 mph, to make this turn. Lap after lap. (Not to mention the other challenging parts of the track, which also require you to use the brakes hard) At the end of the track sessions, the brakes become smoking hot – I can easily smell them whilst sitting in the car. The wheels are covered with brake dust. Yet, throughout many back-to-back track sessions like this all day long, the brakes have never once failed, faded, or showed any signs of distress. The brake pedal remains rock hard throughout the day, with no change whatsoever noted, before, during, or after these flat-out laps. See the picture below, taken of me driving my 308 at Mid-Ohio (with instructor aboard) during one such lap at another part of the track. Note the front end “dive” under braking, the closeness of the spoiler edge to the track, and the lack of front wheel fender clearance. All firm evidence of my being hard on the brakes at the moment this picture was taken. And yes, just to re-confirm, DOT 5 brake fluid was in the car at the time. Upon my return home the next day after my first such annual track session, I bled the brakes, since I was curious to see how the “used” fluid might look. And I was quite pleased to see that, through every subjective criteria (appearance, smell, “feel” between rubbed fingers, etc.) the old “tracked” fluid was just the same as new fresh fluid. If the silicone DOT 5 fluid can hold up to this extreme high temperature use, I have no reservations whatsoever about its use in any casual street driven car. So, based upon my own personal first hand track experiences, I will continue to use DOT 5 fluid in all of my hobby cars. Cheers - DM Image Unavailable, Please Login
I have been using synthetic dot 4/5 for years with great results, From classics to the viper track & street use.
Just worth noting - DOT 5 (not talking about 5.1) is not considered compatible with ABS systems and if you use it in any new car you have voided the warranty on the brake system. I found it to be spongy and not as effective as DOT4 on my my 996 Ducati at Lime Rock. Brembo (among others) does not support it's use in their systems. It's claim to fame is that it won't ruin paint. But as has often been said; it's your car, use whatever you want.
