Re: BTV moisture contamination.

Posted by Owen_Dyneto On 2010/5/23 10:50:58

Perhaps even DOT5 should be purged and bled periodically in vented systems - though not as often as DOT3/4.

I'd strongly agree that DOT5 systems also need to be flushed and refilled, though I can't comment about the frequency. As the fluid level in the master rises and falls, moisture will be drawn in and expelled just as with any other fluid. The difference in the case of DOT5 is that the moisture is essentially insoluble in the fluid and thus won't be absorbed into the fluid, but will remain as discrete water droplets which will ultimately drop to the lowest point of the system because of the difference in density and at that point can initiate rust of the system internally as long as any dissolved oxygen is present.