Just to make your heads explode, these are both excerpts from Oldsmobile factory-issued Chassis Service Manuals. 1970 on the left, 1985 on the right. Note especially the part in the 1970 manual about "bleed the master cylinder last".

 

Wow the one on the left goes against everything I was taught in trade school. The one on the right is what we were taught for non diagonal brake systems. I agree bleeding the master last goes against everything I was taught. That said I did learn a method that was not taught in trade school that worked quite well. Thanks for posting.

 

I don't understand the master cylinder bleeding procedure, but I have over time realized it does not matter whether you start with the fronts or the backs as long as they are done in pairs.

 

^^^This, at least on dual circuit systems that are split front/rear.

 

Interesting. I always learned to bleed farthest to closest.

 

And most of us did from doing single reservoir units.

 

^^ How I learned ^^

 

This same discussion is taking place on the AACA forum. This is from a 1969 Motors Manual. Note the GM bleeding orders, considering that Chevy cars for the most part used exactly the same brake system hardware as did other GM cars of that period. Clearly it doesn't matter.

 

I certainly haven't seen everything, but I have never seen a master cylinder with a bleeder valve in any brand.
I too was taught closest to furthest.

This is of course unless it is a volvo 240 then:

1. Left rear
2. Left front, upper, inner
3. Right front, upper, inner
4. Right rear
5. Right front, outer
6. Right front, lower, inner
7. Left front, outer
8. Left front, lower, inner

 

Seriously? They were original equipment for GMs.

 

That’s odd because most of the master cylinders I’ve seen have bleeder screws. I’ve always bled from the furthest to the closest.

 

Never. I see them clearly in your pics but I’ve never seen them in real life. Didn’t know they existed. I bet this will be one of those things that now I have seen them I will see them everywhere

 

I just got home and for my sanity I checked my Sonoma a Monte Carlo, our 61 studebaker, my 55 Chevy truck, the 64 cutlass and a spare master I have from a 70s Chevy truck

None of them have these bleeders but even my older gm stuff all have replacement masters on them.

would this be something that was dropped from the castings for aftermarket replacement parts?

ive always just bench bled the master and
put it in the car while trying to hook up the lines as fast as possible then bled the brakes at the wheels

I feel like I’ve missed out on a whole new
thing

 

Most replacement M/Cs do not have bleeder screws. Not only is this a cost savings, but frankly I've never found the need for them, especially with my vacuum bleeder.

 

See, I learn stuff all the time on here.

 

I was always taught furthest away right left rear right left front.
If you install a new master or rebuilt master bench bleed.
I never had a problem getting a solid peddle using this method.

 

I agree vacuum bleeding works well.