dazbro Posted November 2, 2016 Share Posted November 2, 2016 H model emergency brake pressure 3800psi, normal brakes 3600psi during finals on approach. Cannot replicate fault on the ground. All other hydraulic pressures remain within limits. Quote Link to comment Share on other sites More sharing options...
hehe Posted November 4, 2016 Share Posted November 4, 2016 How many times was the aux pump turned on during approaches? Multiple pump starts can and will cause high pressure which is allowable to an extent. I know it is caused by emergency brakes because of the 200 psi extra from the aux pump. What you need to do is make sure that those gauges in your flightdeck are accurate. what do they read when system pressure is zero? what do they read when pressurizing system? they should be close to matching system pressure (utility-normal and aux-emergency). (the more times the pump is turned on and off, the higher brake pressure will go because it is not bled off like the sytem pressure unless brakes are used) If your gauges are not accurate, that innacuracy will be multiplied when you get to a higher than normal system pressure. Read your -1 flight manual, the emergency/normal brake pressure is allowed to be over normal psi during multiple pump starts. so its possible your pressures are just experiencing the higher range of operation but doing so with innacurate gauges. If you determine the gauges are fine, check your transmitters. you can back them down a bit to correct the high readings. Hydraullically it could be a low/wrong accumulator pre-charge, bad aux pump, bad power brake control valves, bad accumulator check valve or bad accumulator restrictor. I believe you have a pressure indication issue matched with higher than normal pressures that are allowed during multiple pump starts. You should be able to replicate by simulating touch and go's. run engines, turn on aux pump. turn off pump. wait a minute and turn on pump. continue to this like you were doing touch and go's. don't touch brake pedals. you will most likely see the increase in brake pressure caused by pump starts. Quote Link to comment Share on other sites More sharing options...
AMPTestFE Posted November 11, 2016 Share Posted November 11, 2016 There is a note in the USAF flight manual that addresses this. Quote Link to comment Share on other sites More sharing options...
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