john

do i need to bleed the master cylinder before i install in my car, i know i have to bleed the system after but do i need to bleed before installing

1988RedT2

I would say not. Just install it, fill the reservoir, and bleed it until you don't get any more air bubbles.

dac

I will say this.... kinda related... I bought a $50 pump thingy to do my brakes, which worked okay.



This last time I did them I used speed bleeders.... WOAH I will NEVER bleed brakes the old way again. These things kick ***. $8 a piece.

phinsup

Yea the speed bleeder or the one man brake bleeders are great.



to answer your question, YES I always bleed the master cylinder it is easy as hell and saves a ton of time, otherwise you'll have a ton of air at the beginning of the system.



It is often referred to as "Bench bleeding" just run some tubing from the outgoing connections to the inside of the master cylinder and pump the master cylinder by hand until you don't see any bubbles (note you have to fill the reservior).

Wooffinn

Hey John, wooffinn, foreign mechanic here. It's a good idea just to get some of the air out of it on the bench. You can control the amount of piston movement a lot better also when priming it on the bench. It's very easy to overstroke the Master cylinder when it's in the car and if it's dry inside, you can sometimes damage the internal piston seals. It can be a bit messy but it's worth it. Just a quick note to watch you don't spill any fluid on your paint as it's very good at stripping the paint off if left too long! Just keep a bottle of water close by.[don't wipe it with a rag,it'll get worse!]

When bleeding your system, a quick note is to take the pumping of the pedal slowly, as one it does bleed the air out a lot quicker and two air bubbles aren't split up into millions of small bubbles which usually two or three bleeds to successfully remove.

A good idea to remove the majority of air when mounted to your car, is to bleed it at the pipes at the master cylinder. With a person slowly pushing the pedal, open slightly on the down stroke and close before the pedal is released up.Being the highest point, the majority of air is usually up here.

As Dac said, those bleeders are a good buy. I've got a Mightyvac unit which you can also use to check engine vacuum,distributor diaphragms etc as well as bleed brake/clutch systems. Good luck.

1988RedT2

Well, there you go. Please disregard my earlier post.

SoRRoW

Yes always bench blead the master before putting it on...it will save you time to fight with a sytem full of air..



BUT still bleed your brakes thru the bleaders..if will flush out old dirty brake fluid in your line..so your hitting 2 birds with 1 stone

amp

anyone have any experience with bleeders using compressed air for vacuum..thinkin of buying one instead of the hand pump actuated version..

have used speedbleeders since 97...no qualms with them...at times a bit annoying fumblin around with a lengthy clear hose to see the air bubbles while your at the pedal...specially when your workin the passenger rear..

rotary-tt

Been using the Motive Euro bleeder. It screws right onto the Master cylinder reservior. Works pretty good but seems to bleed slowly. Not sure if the ABS has something to do with the slowness. Alternating gold vs blue ATE racing fluid seems to be a good way to make sure you've bleed out all of the old fluid.



http://www.motiveproducts.com./ordernow_bleeders.htm