ok so I have recently purchased a 1991 s10 blazer from an ex airman. soooo needless to say it has been altered. ABS is bypassed, air conditioner is retro fitted, engine and tranny over hauled... all I all it is an extremely well taken car of car and for 400 bucks I couldn't pass it up. ok so heres the issues
1. the breaks (it came from the factory equipped with a towing package) he was driving it he heard a loud pop and the pedal went all the way to the floor, checking the master cylinder pressure comes out of the front break reservoir but not the back. I'm think wheel cylinder??? but there is not leakage of fluid anywhere, yes it ha drum breaks but still shouldn't there be a sign?
2. there is a dead spot as it idles, it wants to die does fine driving but will die if left t sit. maybe a dead spot it carb? idel adjustment>=?
any help is appreciated. I hate drum breaks.
1991 S-10 blazer 4.3 262 4x4

 

1. It's not too clear what your symptoms really are.
Does it still brake?
How is pedal travel? (A lot of leeway before it starts breaking)?
Which wheels do brake and which do not? (Front yes back no? L/R?)
Does the Blazer have an ABS?
What do you mean with: "checking the master cylinder pressure comes out of the front break reservoir but not the back."?

- Seal in the master cylinder gone and it leaks out towards the vacuum container.
- Mechanical failure in the pedal to master cylinder linkage
- Hose external broken and popped inner liner out and balloons out?
- Some modification to bypass the ABS has failed?

Any diagnostic should be done with extreme care and on stands or a lift and not on the road with a braking system known to be bad. Always consider that the car needs to be blocked as if there were no brakes at all. Never work on an incline with a bad brake system, only on a flat spot with properly chocked wheels. Check the parking brake first for proper function - this is your last resort brake unless detached as well!

2. Do you have a Carb or a TBI? What is the engine code?