I'd like some advice on what to look at replacing. My brake pedal is very low, an air noise can be heard down by the pedal that gets louder when I pull the pedal upwards with my foot. There is some static brake that caused the brake pads to wear down quickly until no material was left and resulted in a blown out caliper piston. I just replaced the caliper and pads and it seems it has gotten worse. I haven't bled the front brakes yet, I know I will need to, but i can't imagine it would make a huge difference, the truck barely stops even on a slight hill with me standing on the pedal. Now i"m stuck wondering if It needs a new master cylinder or if its an issue with my booster

 

Check for a vacuum leak at the check valve in the booster. In my case it was a cracked grommet. Inspect the vac. hose as well.

Good luck.

 

Yeah it maks a huge difference. Bleed it.

 

ok I'll bleed it and see what happens. I just tried to unplug the vacuum line from the booster to try and drive it without power brakes and no dice. Doesn't even vaguely attempt to stop and the pedal seems like it should be a lot harder to press. I took the brake master off of the booster and the linkage moves how it should without the booster hooked up. When it's hooked to vacuum the little piston comes out and stays out. I also noticed the air sound goes away when I unplug vacuum.

 

hmm now i'm not getting any fluid from the bleeder and it's unscrewed all the way. I'm going to get back on this project tomorrow i've been feeling sick lately. LMK what you can make of this. appreciate any help

 

You have to have someone push the brake pedal when you bleed it.

 

Just so you know the procedure, you need to screw all brake bleeders shut. Have someone pump the brakes a few times and then hold the pedal down while you unscrew one bleeder. Be sure to watch your fluid level as you may empty your reservoir. Before the pedal is released, screw the bleeder back in and repeat the process until you get no air in the one bleeder. Repeat all for each brake (both front and rear).

 

I like to use the one man bleeder tool, but still with two people so I can watch the bubbles.

 

When I first bought my truck, I did the 2 man bleed method and I couldn't get any fluid to come out of one of my rear wheel cylinders. I had to end up replacing the wheel cylinder to get fluid to come out. I replaced the other one just for the sake of having consistency with the brakes on the truck.

 

to test your brake booster, there is a tool that is a hand pump with gauge. You pump it a few times, and if your booster holds vacuum, its good.