Corksil

Hey.

car has been sitting for many months, I want to COMPLETELY flush brake lines and fill with 100% new fluid.

I understand that brake fluid is 'hygroscopic' which means it absorbs water which would compromise the design and effectiveness of the brake fluid. Because of this adding a water-based food dye to the fluid is a bad idea.

Are there any dyes I can add to my fluid to safely confirm when I have 100% new fluid in the lines?

and is the technique the furthest brake from reservoir, then the next furthest..?

I understand there are dyed fluids available but I would rather not mail-order something and have to wait. Could I add clothing dye for making tie-die shirts or something similar? Help me think outside the box.

and no my fluid is not 'yellowed with age' and I don't think I will be 100% sure when my new fluid has worked it's way all the way through the system.

I'm there there is a trick for this...

also -- DOT4 or DOT3 or DOT5? Which is the BEST (not just whatever works/cheap)

thanks HT!

94EG8

If it's not discolored I wouldn't even bother to change it honestly. If you want to be really sure about it though disconnect the lines and blow the old fluid through with compressed air. Dye is most likely just going to end up everywhere and tell you nothing.

Use DOT3 fluid.

Corksil

thanks. do you have an estimated capacity of all the lines? for instance - if i flush through 2liters of fluid completely, will that ensure i have replaced all the old?