Re: A Tale of Two Patricians

Posted by HH56 On 2019/6/13 19:53:28

Relief port gives fluid and air a destination. The hydraulic seal lets a tiny amount of fluid pass, even though it might go uphill and fill the channel it still can move to a safe place. Without the port, with the tiny amount of normal leakage which the Bendix description says is there on purpose to lube the seal, when the fluid is subjected to several hundred pounds of pressure thanks to the ram if there is no place to go it eventually fills the seal area and is forced thru a relatively thin vacuum seal and into the power section. A leaking seal would be even worse and the relief port at least gets fluid to the reservoir because that route is much easier than forcing thru another seal. Conversely, if the vacuum side seal fails it can suck a minimal amount of fluid that might be in the channel and normal leakage but since the opening is high in the reservoir it will eventually suck air before pulling much more fluid. Without the port vacuum would also want to pull more than the normal amount of leakage fluid around the hydraulic seal and could pull a lot more into the vacuum side.