so my son tells me his brakes are acting up and can hear them up front. Those check out and now the brake light comes on, to me that signals leak somewhere. I found it, the rear drives side brake shoe fell apart and the cylindar broke, in the process draining the brake fluid resivor, master. Replaced teh wheel cylindar, and new brake shoes in back, and I tried to bleed the brakes. got a feeling I need to bleed the master. Could someone give me a run down on how to bleed the entire brakes system?


Almost forgot, '93 S10-Blazer 4x4 4.3 CPI.

 

For the master cylinder, you basically have to treat it like a bench bleed... I have some old short lines that I made up that screw into the ports on the side of the MC and just curve back up into the res. This allows you to actuate the MC, bleeding the air out, without making a mess under the hood. Once you get the MC bled out, reconnect the lines and make sure that the res is full.

For bleeding the lines, I still find it easiest to have a friend pump up the brakes and hold while I open the bleeder. I have a section of clear hose that I put onto the bleeder and then put into a glass jar. This makes it really easy to see when you have bled them enough, plus it gives you a reference for when to refill the res. As a general rule of thumb, I check the fluid level every 2-3 pumps of the brakes just to ensure that I do not run it dry, but that is for four wheel disk brake vehicles and will be more pumps on a rear drum vehicle while working on the rears.

Start bleeding at the passenger rear, then driver rear, passenger front, finishing off at the driver front. You will want to bleed until clear fluid, free of air bubbles, comes out the bleeder screw at each wheel.

 

I have never bleed tha master before. Do you have some more specific instructions?
Thanks Kyle and Hapy T-Day.

 

As far as the MC goes, just get some hard lines that thread into the ports on the side of the MC, then bend them around so that both of them point into the reservoir opening. Pump the brakes until you no longer see any air escaping the lines. It should be straight fluid.

On older master cylinders with cast iron reservoirs, I would put the ends of the lines below the fluid level in the res so I could more closely look for air coming out. One thing is you can't bleed it too much so just go until you're comfortable with it. Just keep that MC topped off!

 

thanks, i took part of your suggestion.

I had my other son hold the brake pedal to the floor and I cracked open the front (rear brake) fitting on the master, put a rag under to capture the fluid. Then bleed the rear, well the drivers side, I couldnt get the pass side to crack open and didn't want to twist it off with my vise grips.

Thanks Kyle. [sm=admin.gif]