Master cylinder

[psuedopimp]

okay i was bleeding my brakes becuase they suck. they seem to have gotten worse but then again i stopped driving it daily in 06, so i prob was just used to them sucking so bad.

i read somewhere that you could bleed them without the cap on, but i had always bleed brakes with the cap on. well this time i tried it without the cap, and fluid squirted straight up from the back resovoir. i ended up putting the cap on to finish bleeding. bleeding didn't help my brake situation at all.

i am going to replace the master cylinder, but wanted to know if squirting liquid is normal?

[Doug_J]

Yea I know every time ive bleed my brakes ive left the cap on ive forgot to put it on an it squirted evrywhere, wouldnt be so bad but anywhere that brake fluid touches an you have paint their it will bubble and pill.

[psuedopimp]

yeah it is tough on paint! i have seen videos of bench bleeding master cylinder and the cap is off. im wondering if i have a bum master cylinder? for 25 bucks it is worth changing because i have bled the brakes numerous times over the years with minor improvements of braking power.

[Doug_J]

If you push the pedal down nice an slow it shouldnt really squirt everywhere, an it is possible that its bad but I dont think thats what causing it to squirt. I always stick a little tube that fits nicely on the bleeder and have someone push the pedal down while i watch for bubbles. If your sure you dont have any air in the lines make sure your wheel cylinders are not leeking if you dont see fluid around them you could go ahead and replace your master cylinder. The only time ive ever had to replace one was after my truck was parked for like three years and I guess it went bad from sitting.

[7T2]

You can do it without the cap, you just have to go slow. If you jam your foot on the brake pedal you will squirt fluid everywhere, but if you go easy you won't. When you bench-bleed you are usually using a screwdriver to push the piston in, so you don't have as much force behind it, but you can still get it to squirt on the bench if you push too hard.

I usually leave the cap on to prevent the squirting, but leave the bails loose so I don't have to pry them up with a screwdriver each time. Of course this increases the chances of you forgetting to actually tighten them when you are done.

[psuedopimp]

so is there a test to see if the MC is good?

[7T2]

I think if a master cylinder is bad it will leak. Someone else can chime in here....

[psuedopimp]

well it isn't leaking....i wonder if it could be the booster? not sure how to tell if it is bad either.

[Doug_J]

Look at the bottom of you booster if it looks rusty on the bottom or wet then its probably bad and I think it can also leak into the inside of the cab.

[psuedopimp]

well it isn't wet or rusty on the bottom i did notice the other day that there was some fluid around where the vaccum hose enters the booster. but my brakes have been bad since "99 when i got the truck, and they haven't gotten worse.

i don't want to buy a MC if i don't need it. but i would prefer the MC over the booster, that thing is kinda pricey (relatively speaking)

[7T2]

If it's been sitting that long it might be a good idea to drain all the fluid and add new. Brake fluid retains water (moisture) which will decrease your braking efficiency.

There's lots of other things to check. If you have a lot of pedal travel/squishy pedal, your rear brake shoes might be out of adjustment. You need to adjust the adjuster out until they are just barely touching the drum, or you'll have a lot of pedal travel before the brakes start to work.

What exactly are they doing?

[psuedopimp]

pretty much what you described. full travel of the pedal. it will never lock up the fronts or rears.

i guess i will read up on how to adjust the rear brakes.