Thread: changing brake light bulb
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Old 01-29-2014, 11:11 AM
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onehundred80
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Default Re: changing brake light bulb
Originally Posted by pizzaguy

You have about ten minutes before the hydraulic pressure is released (they do this because leaving the pressure on contributes to leaks, the system was not designed for continuous pressure).
I would not say that, all hydraulic system suffer from leak back, possibly through the pump and definitely through the seal. It is necessary as it lubricates the seal. The fluid pressure makes the seal a tighter fit in the bore and a lack of pressure can allow more leakage.
It depends on the seal design how much it leaks in a given situation, split rings types probably leak most , lip seals probably the least. The surface finish of the bore will be a major factor in the leakage and it will be finished to achieve the best conditions for the seal in use.
The design is quite involved in many applications, hydraulics, pneumatics, vacuum and combinations.
 
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