Brake fluid recirculating

[DCIV]

How does brake fluid recirculate? Or does it just stay in the line? Does the hot fluid go away from the heat? The reading online doesn’t seem clear but I did come upon an interesting product.

https://pitstopusa.com/i-5072219-dpi-su ... lator.html

Thoughts? Explanations?


Coop

[mjannusch]

It doesn't recirculate - there's only one way in and out of the caliper. Change your fluid every couple years and it'll be fine. Or if you are track racing, change it before events if you really want to be sure.

Unless you are boiling your brake fluid at the racetrack, no need to make your brakes more complicated than they already are.

[DCIV]

So what’s the point in a resorvor if they don’t circulate? The if a line pops you don’t have brake pressure so the extra fluid isn’t gonna help, if it never makes it way back through vibration, heat, or pulsing then honestly what’s the point?


Coop

[mjannusch]

Because if any air gets in the system then you have reduced or no brake pressure. In any hydraulic system you always need more fluid than is in the lines to ensure a good supply of fluid to the cylinder parts. Over time, some is going to evaporate.

[aaronatstate]

[quote=""mjannusch""]Because if any air gets in the system then you have reduced or no brake pressure. In any hydraulic system you always need more fluid than is in the lines to ensure a good supply of fluid to the cylinder parts. Over time, some is going to evaporate.[/quote]

This. In addition, as the pads wear, the caliper pistons do not return as far, so you need extra fluid to make up for that now additional volume in the system.

Also, exactly ZERO top level race cars or super cars have anything like this. If you don’t need it in Formula 1, or a $2 million super car, you don’t need it in a mid 90s Japanese import.

[aaronatstate]

Another thing, with that gimmick, you’d have to run lines to the caliper, and back from the caliper...a major pita and pointless as well.

Get a good DOT brake fluid, good pads, good rotors, good pad backing plates, and brake ducts. That’ll keep your brake aplenty cool enough to not boil the fluid.

[DCIV]

The pas wear is true, that was never mentioned and is a perfect reason for extra fluid. I just have always seen dirty brake fluid at the resorvar and figured somehow it eventually made it back there.


Coop

[DCIV]

As for the vr4, when I did an abs delete I put speed bleeders on all 4 corners and put the most high tech expensive fluid I could find. Prob doesn’t make that big of difference about the fluid but I did get really good fluid.


Coop