Originally Posted by
Uplinker
As I just posted, (we might have crossed), the hydraulic fluid is NOT trapped; the fluid path is open between the accumulator and the parking brake actuators. Trace the pipework in the diagram I just posted.
"fade out", i.e. pressure reduction, occurs due to micro leaks past the hydraulic seals. This is normal and not an issue when there is a constant supply of pressure from a pump, but if the only pressure supply is from a charged accumulator, that pressure will slowly diminish.
Thanks Uplinker. So if I get it correctly, there is constant hyd fluid presence in the duct from the accumulator to the parking brake actuator via the parking brake valve. Nevertheless, don’t we see a decrease in accumulator pressure as soon as we set the parking brake? ie. When the hydraulic fluid is released from the accumulator?
Finally, the faded out fluid due to leaks returns to the hydraulic tanks I suppose?
Thanks!