Trying to bleed brakes

[TheApocalyptican]

From everything I have read here and in my shop manual, there is a button of some sort that is supposed to be pressed to "open" the combo valve so the brakes can be bled. The 73-87 trucks are supposed to be mounted in the frame cross member, and according to my manual so are the 88-91 Subs. My 90 Sub has it mounted under the master cyl, but it looks nothing like the ones on the 88-98 trucks. I have never done brakes on the full size trucks before, and obviously mine is an odd one due to the year changes.

Can someone point me to where in this picture the damn button I need to press is?

[kris's66lwb]

i never had to hold a button on a combo valve to bleed my rears so idk if i did it wrong or your miss informed

[TheApocalyptican]

Originally Posted by kris's66lwb

i never had to hold a button on a combo valve to bleed my rears so idk if i did it wrong or your miss informed

See, I am wondering if maybe mine doesn't have one, which would explain why I can't find it, lol.

[Dunenutt]

It looks like it is on the drivers side of the valve in your pic. It won't stick out until there is an imballance in the brakes. They make a clip that goes over the shoulder on the fitting.

[Dunenutt]

Where my wonderful drawing indicates.

[TheApocalyptican]

Two things:

1st, that spot had a black rubber cap over it, just like the one on the lower left. Forgot to put it back when I took the pic.

2nd, so what you are saying is that the button won't pop out until I actually start bleeding the system?

[Dunenutt]

Yes, that is why you sometimes need the clip. The button is what actuates the little brake warning switch that is on top of the block.

[TheApocalyptican]

Originally Posted by Dunenutt

Yes, that is why you sometimes need the clip. The button is what actuates the little brake warning switch that is on top of the block.

From the way I read it in the manual, it seemed it was a button that needed pressed in before the bleeding could be done, not held in where it already is so that it doesn't come out. Thanks!!