Air in the master cylinder

[Sunliner]

Well guys, I may have screwed the pooch, trying to do something simple.

'97 S-10 Blazer.

I replaced the pads & shoes; in the process found one leaking wheel cylinder & noted that one of the calipers was sticking, so I replaced both calipers, the front brake hoses & both wheel cylinders.
At one point during the festivities, I put my foot on the brake pedal while one brake hose was only finger tight. I realized what I did as soon as it happened-of course the pedal hitting the floor was a clue too.

Anyway, I jumped out & checked the resevoir & it was all but empty- a small layer of brake fluid was left on the bottom of the resevoir, but that was it. I refilled it, tightened everything up & went ahead with the bleeding operation, hoping for the best.

At this point, the brakes seem to work well, but I noticed that if I hold my foot down on the pedal, it sinks pretty low-not all the way down, but lower than I remember it going before.

Wondering if I got air in the master cylinder and/or ABS modulator when I drained the resevoir. If so, can I just go back & re-bleed the system manually, or should I get it professionally done? I've heard about having to use a special scan tool to cycle the ABS, but I don't know what kind of tool to use.

-Mike

[troubles789]

Sounds like more bleeding time too me. gl

[ricksza]

After bleeding, find some gravel in the road and activate the ABS a few times. Sometimes it will help bleed the air out of the Modulator Valve and bring the pedal up. The scan tool just activates the ABS at a stand still.

[Sunliner]

Ya know, I actually considered doing that!
I figured that activating the ABS might "burp" the air out of the modulator into the lines, then I could go back and manually bleed them again. But:
A. I wasn't 100% sure
B. By this time, I had worked on the thing until midnight & was beat.
C. Kind of exasperated with the whole thing.

So in the name of safety-& since I needed a front-end alignment anyway, I took it to our local mechanic (NOT the dealership) & got them to bleed it.
These guys are really good & as far as I know, have always been honest with me.
The dude did give me a hard time though; he was like "uh oh, 'college boy' tried to work on his truck again & needs us rednecks to bail him out!" ; )
Pretty funny guy. Besides, I did do all the hardware...
Anyway...I'm rolling-and stopping-again.

-Mike

[s10blazerman4x4]

yesssss
sounds just like me with the 91
the one mechanic told me to replace my master and i went ahead and did because thats where we had fluid and then i put the lines back on tight as heck yet they still leaked so took it to a mechanic and for 10 bucks he took em off and retightened