Fluid sa clutch master turns black

[valvura]

I just made a DIY in replacing my revo's OEM clutch master assembly. I
thought it was easy, however, I encountered problems that patiently, I
was also able to resolve:

1) After installing the new clutch master, I found out that the push
rod was longer than the original! I was already thinking of returning
it to the store (in Pasay) where I bought it, kaya lang, malaking
abala (since I live in Sta. Rosa, Lag.). So what I did, kinalas ko uli then re-used the old push rod and it was quite easy to remove kasi ring lock lang ang tatangalin. So successful ako doon and I reinstalled the clutch master.

2) At first try, no resistance ang clutch pedal even after a number of
pumping and bleeding. Medyo hopeless na ako until I tried to bleed the master cylinder (which I should have done in the first place), by
releasing the copper tube attached. Then nag re-bleed ako sa valve
near the secondary. Finally, I got the resistance sa pedal and puwede
na mai-shift ang gear.

Lessons learned: (a) Do not bleed or flush existing fluid in the line
before installation, just detach the copper tube at the clutch master
(just provide a pan below it to collect fluid spills). (b) Bleed the
new clutch master first before installing, but make sure you check the
dimensions of components of the new against the old clutch master.
(Baka hindi tanggapin ng store for replacement kung may fluid na).

I just spent for the cost of OEM clutch master at Php 2,950.00.

Hope this could be of help to those who intend to DIY their clutch
master assembly.

[spyghost]

just replaced my clutch secondary slave since i had a leak. i drained all existing fluid and replaced with new prestone dot3. the line was bled well until the fluid that comes out is clear. i bled it 10 more times after it was clear just to be sure.

after a month, i just noticed, my fluid is already turning dark again. i don't have leaks on both primary and secondary. i don't think this is still normal. should i also change the master cylinder internals?