Brake Fluid Comparison                                                                                FAQ Home

 Volvo Maintenance FAQ for 7xx/9xx/90 Cars                                                                                                                     Version 5.0

This information was compiled by Gary Hackney and was edited for Volvo cars by S. Ringlee.  Many of the racing fluids with poor wet boiling points or fluid incompatiblities were removed since these fluids are not designed for everyday use.  Only Glycol (Polyalkylene Glycol Ether) fluids are shown; no silicone DOT 5 fluids are listed because they may not be used in Volvo cars without major brake system modifications.

The DOT specifications are based on the concept of wet and dry boiling points.  The dry boiling point is applicable when fluid is fresh and the wet boiling point after the fluid has been exposed to moisture and has had the opportunity to adsorb water. The minimum values for the wet and dry boiling points are specified for each DOT level, and increase from 3 through 5. Note that these are minimum values, and there is no constraint on by how much a manufacturer may exceed them.  To achieve a DOT rating, the fluid must meet both dry and wet boiling point specifications.  In addition to DOT level, another important consideration in selecting a brake fluid is the presence of anti-corrosion additives, commonly found in street fluids but not in track fluids.  Note that Volvo ABS-equipped cars must have brake fluids flushed every two years to remove moisture, renew additives, and prevent corrosion.

[From Hackney:] The "Estimated BP After 6-months" column is estimated based on a page I found that says brake fluid gains about 3.5% moisture per year, which is where the wet boiling point is measured.  Assuming linear degradation this column is where you'd be. The last two columns may be confusing.  They're the price per ounce, divided by the degrees F the fluid exceeds the dry or wet DOT spec; sort of a price for performance number where lower is better.  Yeah, I'm an engineer.  FWIW:  My conclusion:  ATE Type 200 and Super Blue are not only the cheapest of the performance brake fluids, they are also the cheapest per degree of boil protection, and have a very high 6-month BP estimate. In addition you can alternate with each change and the color difference will tell you when you're done.   [Note that ATE Blue is not DOT-approved because of the color.]  ATE and some of the higher-performance fluids are available from  Valvoline and Castrol are commonly found in mass merchandisers.

Conversions:      F = (C x 1.8) + 32
                          C = (F - 32) x .5555

Fluid Dry BP Wet BP Est. BP after 6 months US $/oz US $/oz per °F > DOT4
Dry Wet
Castrol SRF 590 518 554 $2.076 $.0144 $.0100
NEO Super DOT 585 421 503   0.983   .0071   .0089
Motul Racing 600 585 421 503   0.712   .0051   .0065
Motul DOT 5.1 509 365 437   0.675   .0107   .0125
ATE Type 200/ATE Super Blue 536 392 464   0.295   .0033   .0036
Valvoline High Perf Synpower 513 333 423   0.16   .0023   .0073
ATE SL 500 329 415      
Castrol LMA 450 311 381   0.219   .0547
DOT 5 Spec 500 346 423 n/a n/a n/a
DOT 4 Spec 446 311 379 n/a n/a n/a
DOT 3 Spec 401 284 343 n/a n/a n/a





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