Wilwood XR Race Only Brake Fluid 500ml ~ 340°C Dry Boiling Point

Dry Boiling Point

Wilwood's new extreme XR Race-Only brake fluid formula has been in development for some time and was tested by top-level race teams through 2020. We have developed the most advanced fluid available, with one of the highest dry boiling points ever. This formula has been used by teams in the highest classes of motorsports across the globe. Drivers who have tested with it have not wanted to go back to the fluid they previously used.

XR Race-Only brake fluid was formulated to give drivers and teams an upgrade option in race-only vehicles that run under the most demanding, extreme high-temperature conditions.

Wilwood's XR Race-Only brake fluid has one of the highest dry boiling points of any readily available fluid. For racers, the wet boiling point is irrelevant; only a high dry boiling specification matters. If the brakes are bled and filled with fresh fluid before events as part of your pre-race ritual, you will never absorb enough moisture to lower the dry boiling point.

All brake fluid can absorb water, and, even at low humidity, there is moisture in the ambient air. Only if you were to let your car sit for months in the off-season would it absorb enough water to reduce the boiling point to anything near the wet number. Wet boiling is measured at saturation, which is nearly 4% water, but a properly maintained race car eliminates that concern.

While in storage, you can take a couple of steps to prevent moisture from creeping into the master cylinder. If your car has a reservoir with rubber bellows in the cap, the rubber will do an excellent job keeping water out of the system. For master cylinders without bellows, or for an extra measure of protection, wrap a plastic bag around it and seal with a rubber band.

Every can of XR brake fluid is sealed airtight from the factory to keep out moisture and ensure optimum performance. Once opened, the container should be kept in a zip lock bag for future use. 

When switching over to Wilwood XR Race-Only fluid, you should flush all the old fluid from your car's entire system. Contamination with other fluids will significantly reduce XR’s 645° F boiling point, but there are no adverse effects from using XR to flush the old fluid out.

Race type systems with twin master cylinders and balance bar:

1. Remove reservoir caps and suck out old fluid with a turkey baster, syringe, or vacuum pump.

2. Disconnect the calipers from the brake lines and put catch cans under the lines.

3. Fill the reservoir with Wilwood XR Race Only fluid.

4. In systems with master cylinders above calipers, the system will begin to gravity bleed through the lines. You can pump the pedal slowly to speed up the process.

5. In systems with master cylinders below the calipers, you will have to pump the pedal slowly to push fluid through.

6. Refill as needed and make sure the master cylinder reservoirs don’t run dry.

7. When clean, clear, fresh fluid is dripping out of the brake lines, reconnect them to the calipers.

8. Bleed the calipers using bleed bottles (Wilwood recommends part number 260-16018) until all the old fluid is flushed out.

9. With a balance bar system, you will have to bleed two calipers at once. We show you how on our YouTube video: Wilwood “Purge” Brake Bleeding.

10. Clean and inspect all brake line connections and bleed screws for leaks and moisture while applying pressure to the system with the brake pedal.

11. Bleed calipers again after initial use to ensure the system is entirely free of air and set proper fluid level in master cylinder reservoirs.

Street-type tandem master cylinder systems: Follow the same steps as above, but you can do one caliper at a time.

Vehicles with antilock brakes (ABS): Follow the manufacturer's procedure for bleeding the ABS module. If the module has not been run dry, you should be able to bleed as above, but with the vehicle running and the ABS system powered up.