Tundra brake upgrade,no front brakes now

Done the upgrade with rotors and pads from Superstop,calipers were bought locally. Bled several times but almost zero brakes now,before the upgrade when sitting at a stop the pedal would slowly go down. Master cylinder going bad? What else could it be?

 

Master cylinder is a main suspect for sinking brake pedal if no external leak is present.

Calipers bleeder screws - are they on the top or on the bottom of the calipers?

 

Recheck everything....

 

Probably master cylinder - fluid getting past internal piston seals due to age/wear.

 

They're in the bottom,replaced master cylinder earlier but no change. If you pump the breaks with engine off,you get spongy resistance but never the "back wall" feeling you get when the pedal stops moving forward. Crank the truck,pedal goes to the floor and no resistance at all just all way to the floor. I can still feel the pedal going to the floor like there's a leak. No issue beforehand with old brakes other than the calipers needed attention. Don't get why the pedal goes to the floor as soon as you crank it either.

 

^Did you bench bleed the master cylinder before installation?

Could also be air trapped in the ABS unit, which would require a scan tool with bidirectional control to bleed.

 

I've changed out everything mentioned before but not as much at the same time and never had problems and it was okay before I did this.

 

The bleed screws on the calipers suppose to be on the top to get the air out of the caliper. Sounds like the calipers are switched right to left, installed on the wrong sides.

 

Never thought about that but did notice the were in the bottom unlike the old ones but didn't realize they would trap air like that tho. Damn it man!

 

And there it is....you have air trapped because the bleeders always need to be on top to allow air to escape. That's why you have such a poor pedal feel, you are compressing air instead of brake fluid.

 

that caught my attention as well!