Brake fluid
Race Director
Joined: Dec 2013
Posts: 12,502
Likes: 3,629
Every 2 years the brake system should be power flushed for just normal driving (including cycling the ABS pump to replace the fluid in it as well.
Hence in 2 years, the fluid has absorbed enough moisture out of the air into the fluid to make a difference in pedal pressure needed.
Plus, if you power flush every two years, it keeps the system clean, so you don't end up with crap in it/crap on the inside of the tank as well.
As for brake fluid, dot 4 will pull moisture faster, but has a higher boiling point as well.
So with Prestone Dot 4 having a dry boiling point of 510, your only going to DD the car and power flush the system every two years, it your best option.
Motul 660 has a higher dry boiling point of 617, but at the cost of about $60 over the $20 your going to pay for the needed amount of fluid to do a power flush (takes about a quart of fluid), Prestone dot 4 is fine for DD and light track use cars.
If your not going to power flush every 2 years, just DD'g the car driving miss daisy, then run dot 3 isntead. It has a lower boiling point, but absorbs moisture slower, so may get you an extra year or two out of the fluid before you start noticing it at the pedal instead. The downside with flushes pushed out much longer/too long, going to have a lot more debris in the fluid of just moisture alone (brake dust and rubber from the seals and valves) , so may take more fluid or even having to pull the tank to clean out the inside of it when the fluid is not power fluid every two years isntead.
As for track events like HPDE's, you power flush after each weekend even, and more if you are getting the brake fluid even closer to it boiling point each session. Hence if you are running R compound tires, you will be working the brakes a lot harder, getting the fluid a lot hotter, and here is where you are will run Motul 660 with it 617 dry boiling point instead.
Hence in 2 years, the fluid has absorbed enough moisture out of the air into the fluid to make a difference in pedal pressure needed.
Plus, if you power flush every two years, it keeps the system clean, so you don't end up with crap in it/crap on the inside of the tank as well.
As for brake fluid, dot 4 will pull moisture faster, but has a higher boiling point as well.
So with Prestone Dot 4 having a dry boiling point of 510, your only going to DD the car and power flush the system every two years, it your best option.
Motul 660 has a higher dry boiling point of 617, but at the cost of about $60 over the $20 your going to pay for the needed amount of fluid to do a power flush (takes about a quart of fluid), Prestone dot 4 is fine for DD and light track use cars.
If your not going to power flush every 2 years, just DD'g the car driving miss daisy, then run dot 3 isntead. It has a lower boiling point, but absorbs moisture slower, so may get you an extra year or two out of the fluid before you start noticing it at the pedal instead. The downside with flushes pushed out much longer/too long, going to have a lot more debris in the fluid of just moisture alone (brake dust and rubber from the seals and valves) , so may take more fluid or even having to pull the tank to clean out the inside of it when the fluid is not power fluid every two years isntead.
As for track events like HPDE's, you power flush after each weekend even, and more if you are getting the brake fluid even closer to it boiling point each session. Hence if you are running R compound tires, you will be working the brakes a lot harder, getting the fluid a lot hotter, and here is where you are will run Motul 660 with it 617 dry boiling point instead.
