Brake booster test

[dom14]

I would not waste time to pump the system empty first, just empty/evacuate the reservoir and top up with new fluid and keep bleeding/pumping until new fluid comes out, regularly topping up reservoir with new fluid that way you avoid creating unnecessary air locks as well which will actually speed up the job .

Don't mix different grade brake fluids though.

Regards

Ok cool, thanx mate.
I guess I'll be stashing away the old brake oil for future wound healing applications.


BTW, the vehicle is dual fuel & it idles only around 600ish when cold started.
Fast idle is not working on both fuels when cold at the moment.
Not sure the reason.
I just noticed, when cold started and when I press the brake pedal hard, rpm drops by around 150-200.
Once it's warmed up, I can't see any significant change of RPM when brake pedal is pressed hard.
Does this mean, I still have some issues with the vacuum lines(vacuum level)?!
I was suppose to properly test the vacuum level using vacuum tester.
I can't find the damn thing. Still looking for it.
I'm still suspicious about the vacuum system.
It didn't do well with the cigarette smoke test(my previous thread).
I need to do a proper vacuum test soon.
RPM drop happens when I press the pedal hard, probably meaning a small vacuum leak,
either in the booster or other parts of the vacuum lines??!!

Any thoughts?

Thanx