I need help. Bled my brakes multiple times. Changed master cylinder and yes I did bleed it. Bled all the old fluid out after that but I still have a spongy pedal. Truck takes about six seconds to come to stop when full depressing brake pedal. And that’s at around 30-35 mph. I checked the brake lines, and my booster is working. Please help if you can
What year Frontier? ABS or no? How did you bleed? Gravity? Pedal pump? Vacuum pump bleeder? Pressure bleed at the master? Did you bleed the master on the bench only or did you let the lines dribble on the truck while someone pushed the pedal?
Depending on age (10+ years), the rubber brake lines could be the problem.
They can lose their rigidity and expand under pressure.
1 Like
As mentioned, what year truck is this? I think the early ones used rear drums and shoes.
If the rear shoes are worn or out of adjustment that can mimic a faulty master cylinder. If this is the case then maybe the master cylinder was not the problem to begin with.
It’s a 02 frontier and yes it has ABS. I bench bled the master and I bled it with a MightyVac and also tried opening the bleeders while somebody pumped the brake pedal for me.
It’s an 02. And I changed the the brakes shoes cause they were really worn down. I adjusted them too but still spongy pedal.
when you bled the brakes did you start from the right rear, then left rear, then right front and then left front?
Yup in that order
and you made sure you kept the master filled with fluid at all times? I would try bleeding them again. it seems like there is still air in the system.
If you pump the pedal, do you get a firmer pedal feel? If so, I would say there is air in the system. If not I would look at the rear adjustment.
Yea master cylinder was full at all times. I actually bled them again yesterday to flush out all the fluid that was in the lines. Still a spongy pedal. Thinking it could be my ABS modulator?
Try bleeding the master cylinder again. Lightly push on the brake pedal and crack each line one at a time to let a small amount of fluid out, then tighten. Easy to get an air bubble right there at the master.
Good ideas above. As long as the MC is new and bench bled, I seem to get best results bleeding brakes myself, a one-man method, by opening the bleeder, pressing the pedal down gently (w/my hand only) to about 80% of the way, holding it there w/a stick, closing the bleeder, then gently allowing the pedal to rise back up. For some reason I don’t get as good of results using the two-man method.
This is how the brakes are bled if the ABS module has been opened up.
This is done by pumping the brake pedal firmly 40 times with the ignition off . After repairs have been made, the lines can be bled manually, with a conventional power bleeder, injector tool or vacuum bleeder. With all of these methods, leave the key off so the ABS pump does not pressurize the accumulator.
Tester
Ok everyone. I tried all suggestions but no luck. I talked to a friend and he said the booster may be causing my spongy brake pedal. What do you guys think?
I would guess air in the lines before a booster for spongy brake pedal (break petal 
), just my guess
Yup I used the mightyvac exactly like the second one.
A bad vacuum booster will usually cause a hard pedal.
2 Likes
just out of curiosity did you change to a different type of brake pads? like going from semi-metallic to non- metallic pads. and did you get any brake fluid on the pads? just trying to rule out the basics. also it could be bad brake hoses like circuitsmith said.