Flushing the brake system between 5605 and Royco 782

[Thermos]

During this year's condition inspection I'm working through the Van's service letter for Royco 782 brake fluid and improved O-rings. Royco says that 782 and MIL-H-5606 are compatible, so I plan to just drain the existing fluid and service with 782.

Is there any reason to flush the system before putting in the new fluid? I hope not, cause I don't want to go through the mess. I've done a VAF search and didn't find much.

If a courtesy flush is advisable, what's the best way to do it?

TIA,

Dave

 

[RV6_flyer]

Flush not necessary.

You will push enough of the new stuff through when you bleed the system that it will be clean.

I may toss out the first oz out and recycle the rest for use in the brake system.

 

[BobTurner]

I may toss out the first oz out and recycle the rest for use in the brake system.

If you re-use the old stuff, you’ll loose the main benefit of the Royco- higher flash point.

 

[Taltruda]

I pulled the calipers off, rested them in a container, then pumped the brakes till the pistons popped out.. The old fluid will just drain out.. Then when you reassemble and bleed in the new stuff, you’ll be good to go. You do bleed from the bottom up, right? The important part is that the synthetic is in the system nearest the wheels.. where it could get hottest anyway.

 

[RVDan]

The Mil Spec that 782 meets says that the 2 are miscible and can be mixed without a purge of the system. The only effect of the residual 5606 would be to very slightly reduce the flash point of the 782.