I hope I post this where it belongs, forgive me if I do not. This is my first real post here,I have been looking in on the site for answers for the past year, all the questions and issues I have encountered had already been addressed here. For that, I want to give abig shout out to everyone here who has posted up help, including Kyle, Korey, Rooster, Flux, Chevy Lover, thankyou for sharing information I don't have in a way I can understand. You have helped me keep my 91 S10 on the road and I am grateful.

Now, I am working on my 89 S10. Replaced the master cylinder and a rusted out piece of metal line, no problem. Installing the remanufactured MC there was some resistance from the push rod on the booster. Went ahead and tried the pedal, rock solid and hardly any downward movement. Nothing bleeding out the rear tires, so I got to get into the push rod issue.

The instructions say that on the push rod must be adjusted, or shims used if there is resistance.Instructions show someone turning the rod with pliers and a wrench to adjust. I turned the rod with my fingers, it just slid out. Used a precision cut 2x4 to hold down brake pedal, pushed out the lipstick shaped cylinder that the rod sits in. the lipstick had a pepperoni sized diaphram that I was able to adjust a little then reinstalled. TheMC went into place without resistance and I thought I was on the right track, but when I checked the pedal wasstill rock solid.
I'm not 100%behindthese instructions, they sent 2 plastic plugs to help bench bleed it, but they barely fit, leaked fluid, so I used the method of bleeding it in the vehiche with the metal lines, a trick I learned here and used to bleed the MC in my other truck.

Went and searched the archive here, didn't find anything. I did a google search and found a 6 year old thread on a plow site, everyone there had an opinion, and they were all right, as far as they were concerned. They post up roughly on each other, I scurried on back here where everyone posts upkindlyand use smileys. You can take a look at it here

http://server1.lawnsite.com/showthre...463&page=4

So that is about where I am at, and my question is: has anyone had to deal with this before? and
how did you do it?
do they make MC shims? or a shim suggestion that might do the trick?

If I can clear anything up, let me know. I appreciate any help. Thankyou in advance
Mike

 

You say that you can't get fluid out of the rear wheel cylinders, that's an indication that the proportioning valve needs to be re-set. Try bleeding more fluid from a front wheel cylinder. As the brake pedal comes close to the floor you should feel a resistance, then as you continue to press the pedal and overcome the resistance have someone close the bleeder screw before allowing the pedal to return.
Now try bleeding the rear brakes again, you should now get fluid.

Try this first and post up as to your results.

 

Thanks for the help Chevy Lover, I had to waita couple of days for some help from my wife on the brake pedal. We were able to push 32 oz. of clean fluid through the lines using your method. After getting some fluid to the rear cylinders,I closed off the front right and was unable to get fluid to the rear again. I read about using a jumper wire on the pressure differenital switch to test it,(9-14 haynes) thinking about trying that tomorrow.

My question is, do I need to test the switch, or does it correct itself after I bleed more fluid through?

I feel like we are on the right track, but I am unsure what I should expect from the pressure switch, and unsure about getting the fluid to bleed freely thru the back. Thanks again for hwelping out.

 

If you are getting fluid to all 4 wheels, then push the brake pedal very quickly (almost a kick) with all bleeders closed and the proportioning valve should reset, turning off the warning light.

 

Thany you Chevy Lover

I was able to bleed the rear lines. Truck is back on the road, and the brakes work better now than they have since the truck beacme mine. I'm just getting started on it, I'll be around. Thanks again