DOT 4 Synthetic Brake Fluid
07-13-2010, 09:28 PM
#1
Rennlist Member
Thread Starter
Join Date: May 2010
Posts: 57
Likes: 0
Received 0 Likes
on
0 Posts
DOT 4 Synthetic Brake Fluid
I know the Manual says not to use Synthetic brake fluid. I have been told from my previous cars that was for DOT 5 synthetics. I was told that the DOT 3 and 4 fluids will mix with the mineral DOT 3 and 4 fluids. Synthetic 3 and 4 seem to be the only stuff available in the parts stores. is anyone using this stuff or does everyone go to the dealer for fluid?
John
John
07-14-2010, 01:03 AM
#2
Race Director
Is there really such a thing as "mineral" brake fluid? I thought all brake fluid would be synthetic? I use ATE Gold in my cars, fully acceptable. If I need to do a major flush (when I buy a "new" used car) I flush it first w/ the Valvoline "synthetic" fluid followed by the ATE Gold.
07-14-2010, 01:33 AM
#3
Banned
Join Date: Feb 2002
Location: Denver, CO
Posts: 194
Likes: 0
Received 0 Likes
on
0 Posts
You don't mention what you're trying to put the brake fluid in so I'm gonna make some educated guesses here.... I suspect it DOES NOT say not to use Synthetic brake fluid (and I tell you why in a bit) but it actaully says, "Dont use a Silicone Brake Fluid (DOT 5)
So assuing that, first thing is, depending on how you tend to use the word "synthesis" either ALL DOT 3, DOT 4 and DOT 5.1 brake fluids ARE synthetic or ALL DOT 3, DOT 4 and DOT 5.1 brake fluids ARE NOT synthetic. Furthermore DOT 3, DOT 4 & DOT 5.1 ARE NOT mineral brake fluids and should not be confused with such.
Wikipedia states a chemical synthesis is "the execution of chemical reactions to form a more complex molecule from chemical precursors" This process is EXACTLY the process used to make brake fluid.
DOT 3 brake fluids are glycol based (SAE J1703) and all DOT 4 & DOT 5.1 brake fluids are borate ester based (SAE J1704). DOT 5 brake fluid, also know as LWTF (Low Water Tolerant Fluids) are, as of 1995 (date of last revision to SAE J1705) are silicone based, however neither J1705 or FMVSS 116 specifically state a base material for DOT 5 brake fluid. Silicone brake fluid, also know as SBBF (silicone based brake fluid) is non-hygroscopic (does not absorb moisture).
A typical mis-understanding of DOT 5 SBBF is that it is NOT compatible with the seals and such in a brake system. This is 100% INCORRECT. SAE J1705 specifically states, (Appendix A.2.1) "SBBF must be functinally compatible with SAE J1703 (DOT 3) motor vehicle brake fluids and with braking systems designed for such fluids. The term "functionally compatible" means that the braking system will perform satisfactorily should the two types of fluids be mixed, and that no undesirable interaction will occur. This does not imply complete miscibility since SBBFs are not completely miscible with present SAE J1703 fluids"
This section goes on to say mixing of SBBF with SAE J1703 fluids are not known to product adverse effects but not all combinations have been tried.
In any case, I suspect what you are looking for is a DOT 3 or DOT 4 brake fluid. there are many varities and brands available from very low priced, low performance brands like the $4.99 quart you can find at Ppe Boys to mid-priced brands like ATE, Wilwood, AP Racing and Motul on up to the hghest performance racing brake fluids like Castrol SRF & Prospeed RS683. As I don't want this to sound like a commerical I will not suggest a brand....
I hope this helps....
Michael
So assuing that, first thing is, depending on how you tend to use the word "synthesis" either ALL DOT 3, DOT 4 and DOT 5.1 brake fluids ARE synthetic or ALL DOT 3, DOT 4 and DOT 5.1 brake fluids ARE NOT synthetic. Furthermore DOT 3, DOT 4 & DOT 5.1 ARE NOT mineral brake fluids and should not be confused with such.
Wikipedia states a chemical synthesis is "the execution of chemical reactions to form a more complex molecule from chemical precursors" This process is EXACTLY the process used to make brake fluid.
DOT 3 brake fluids are glycol based (SAE J1703) and all DOT 4 & DOT 5.1 brake fluids are borate ester based (SAE J1704). DOT 5 brake fluid, also know as LWTF (Low Water Tolerant Fluids) are, as of 1995 (date of last revision to SAE J1705) are silicone based, however neither J1705 or FMVSS 116 specifically state a base material for DOT 5 brake fluid. Silicone brake fluid, also know as SBBF (silicone based brake fluid) is non-hygroscopic (does not absorb moisture).
A typical mis-understanding of DOT 5 SBBF is that it is NOT compatible with the seals and such in a brake system. This is 100% INCORRECT. SAE J1705 specifically states, (Appendix A.2.1) "SBBF must be functinally compatible with SAE J1703 (DOT 3) motor vehicle brake fluids and with braking systems designed for such fluids. The term "functionally compatible" means that the braking system will perform satisfactorily should the two types of fluids be mixed, and that no undesirable interaction will occur. This does not imply complete miscibility since SBBFs are not completely miscible with present SAE J1703 fluids"
This section goes on to say mixing of SBBF with SAE J1703 fluids are not known to product adverse effects but not all combinations have been tried.
In any case, I suspect what you are looking for is a DOT 3 or DOT 4 brake fluid. there are many varities and brands available from very low priced, low performance brands like the $4.99 quart you can find at Ppe Boys to mid-priced brands like ATE, Wilwood, AP Racing and Motul on up to the hghest performance racing brake fluids like Castrol SRF & Prospeed RS683. As I don't want this to sound like a commerical I will not suggest a brand....
I hope this helps....
Michael
07-17-2010, 02:53 PM
#4
Rennlist Member
Thread Starter
Join Date: May 2010
Posts: 57
Likes: 0
Received 0 Likes
on
0 Posts
Thank you,
Your right. I ment silicon brake fluid. The vendors are confusing things by adding "synthetic" to their product to make it sound like it is higher quality. I realize it is all basiclly synthetic. Mineral was the wrong term to use.
John
Your right. I ment silicon brake fluid. The vendors are confusing things by adding "synthetic" to their product to make it sound like it is higher quality. I realize it is all basiclly synthetic. Mineral was the wrong term to use.
John
