MIL-5606 to ROYCO-782

What, if anything, would I have to do to replace the MIL-5606 hydraulic fluid fluid currently in my brake system with ROYCO-782 hydraulic fluid? Can I just drain all the 5606 and replace it with 782 or is it more complicated than that?

GalinHdz said:

What, if anything, would I have to do to replace the MIL-5606 hydraulic fluid fluid currently in my brake system with ROYCO-782 hydraulic fluid? Can I just drain all the 5606 and replace it with 782 or is it more complicated than that?

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I recently discussed this with Matco. George said they are "compatible" meaning they will mix, but won't provide the higher temp performance without some purge. I did a bench test and while the color dissolved in denatured alcohol, there were suspended beads of 782. Mineral spirits will dissolve and clean it, but not sure how one would effectively purge a system. A steady stream of low pressure air might do it if left blowing through for 30 min or so after filling and blowing out the mineral spirits. If the calipers are apart it would be easier.

As a result I just installed the 782 in the clean system.