29th June 2026: DriveTec is warning garages to double-check brake fluid specifications on modern vehicles after seeing a growing issue in workshops: reservoir caps that don’t match the OE requirement. 

On many post-2015 vehicles, the cap still states “DOT 4” even where the system is designed for DOT 4 Low Viscosity (LV). Going by the cap alone can lead to the wrong fluid being used. 

DriveTec is advising technicians to rely on manufacturer specifications rather than under-bonnet labelling when confirming the correct product. 

The shift to advanced braking systems means low-viscosity fluid is now critical to system performance. DOT 4 LV (ISO 4925 Class 6) is formulated to flow more quickly at low temperatures, supporting the rapid response needed for systems such as ABS, ESC and automatic emergency braking. 

Using standard DOT 4 in systems calibrated for low-viscosity fluid can slow system response and weaken brake intervention when it’s needed most, particularly in colder conditions or high-demand braking events. 

DriveTec has expanded its range with an OE-compliant DOT 4 LV fluid, available exclusively through GSF Car Parts. 

Justin Wasling, Commercial Programme Director at GSF Car Parts, said: “We’re seeing more vehicles where the cap says DOT 4, but the OE spec is DOT 4 LV.

“If you’re taking the cap at face value, it’s easy to get it wrong. The only reliable way is to check the manufacturer spec.

“It might not show immediately, but the wrong fluid will affect how these systems respond under pressure.

“If garages are unsure, our 215-branch network is there to support with the right product and advice.”

GSF is advising workshops to stock DOT 4 LV as standard to avoid being caught out.