LS400BOY

ok i replace my rear brake caliper due to old 1 the shaft poped out because a bolt was loose on the caliper and im asuming alot of air got into my system during tat time ,because i seen it leaking for a week untill my brakes finally reached to the floor when i stop,i replaced my whole hub assembly because of bearing went bad,i tryed to bleed all 4 brakes and still fell like there was air in my system when i stop?? ok well i ordered a rear abs sensor for it thinking that would do the trick,installed it and bleed all the brakes again, its still feel likes theres air in the brakes!!! what could this be??????????did too much air get into the system? or is there another problem going on here

cobalt91

What proccedure are you using to bleed the brakes?

RA40

iTrader: (6)

If you are not seeing air bubbles during the bleeding process, it is unlikely you have air. What type of pedal feel are you looking for? The brake pedal should not go to the floor during normal braking operation.

With all the work you've done, I'm presuming the brake lines are in good shape. No bulges, kinks or other issues that may cause a different pedal feel.

LS400BOY

im bleeeding each wheel at a time,2 person job pump brakes then release vavle a couple of time per wheel

LS400BOY

oh no that was at the beggening when i had found out my brakes was bnad and noticed the cylinder that pushed the brakes together was gone,so thats where it started to leak at them assuming where the air had got in, but now everytime i try to stop it will stop but feels like it surges or the air in the lines??

RA40

iTrader: (6)

The brake should be even feeling and as the pedal is pushed for progressive application of the calipers. If it is "surging" there is additional issues to look into. Are the vacuum lines to the booster and ABS-TRAC unit in good shape? This may be a part to look into. You would usually get a warning light on the dash.

Hard to qualify what you are feeling, are the wheel bearings good, warped rotor are the other calipers in good working condition?

LS400BOY

I dont know if surging was a good word but just feels like theres air in my lines,there are no brake lights on my dash popping up at all,do you think completly bleeding them fresh should do the trick??? Oh sorry about the caps lol

cobalt91

When the piston came out of the rear caliper, did it drain the master cylinder? If so then yes the whole system needs to be bled.

j2b4o

Air in the lines causes the pedal to drop to to the floor with light pressure sometimes intermittently. Is this what is happening??

LS400BOY

no it did not,but cought it as the last second

LS400BOY

no,when the piston came out of the caliper with the backside brake pad thats when it went to the floor,i replaced the caliper with the brake pads and it went to normal braking but feels like theres air in lines

RA40

iTrader: (6)

Simply put, how does the brake feel after all these fixes? Take the car into a shop and have the technician inspect the brake system. You have only stated it feels like there is "air in the lines" but you have not described any additional symptoms to indicate.

What brake pedal feel are you expecting?

LS400BOY

what is there to tell,when i try to stop its if feels like its slidding on my foot,i feels like it slips/shakes on pedal

RA40

iTrader: (6)

That's not air in the lines. Your ABS may be coming in and thus an ABS sensor or unit. It can also be the wheel bearings are shot, front strut bushing as this will allow the LCA to shift position but you would normally hear it clunking while braking and going over bumps. Master cylinder and or brake booster. This is why I asked if the vacuum lines are in good shape to all these components.

I suspect the ABS unit, brake booster, master cylinder assembly and sensor.

LS400BOY

HMNNN, i just replaced the whole hub assembly because i did have a bad bearin and i just replaced the abs brake sensor