need help diagnosis my brakes

[darkmist2k1]

i have a 93 turbo legacy sedan

my brake pedal is soft.. i tried bleeding them twice.. still soft.. i change the master cylinder and bled it twice again and its still soft...(while it was bleeding the pedal is really hard.. as soon as starts the car pedal become really soft)

the only way for me to get some brake pressure while driving is to pump it two time then i the brake actually bites( at 30 percent on the pedal) .. if not i have to press down like 80 percent before i get to slow down

my pads are good.. rotor are good.. inspected my hoses.. nothing is leaking..completely flush the brake system twice...

any susgestion?

Sunny

[NuwanD]

2 guesses...

1) Seems like your feeling the mush from the brake booster since it's when the car is on.

2) If it's occuring (ie; double pump required) when driving I'd suspect a wheel bearing is shot, most likely a front. This allows the hub/rotor/wheel assembly to wobble and push the pistons back into the caliper. Your first application of the pedal brings the pistons/pads close to the rotor, and the second application get the pads contacted.

I'm assuming your rubber flex lines are in decent shape.

Hope that helps

[darkmist2k1]

2 guesses...

1) Seems like your feeling the mush from the brake booster since it's when the car is on.

2) If it's occuring (ie; double pump required) when driving I'd suspect a wheel bearing is shot, most likely a front. This allows the hub/rotor/wheel assembly to wobble and push the pistons back into the caliper. Your first application of the pedal brings the pistons/pads close to the rotor, and the second application get the pads contacted.

I'm assuming your rubber flex lines are in decent shape.

Hope that helps

wheel bearing is good.. all around.. rubber line are decent shape..

brake booster... sound expensive..any other sugesstions

[subytech]

What haveyou done to your brake system lately, did you bench bleed your mastercylinder when you replaced it?

Dont ask me why I know this but if you replaced the calapers make sure they are on the correct sides of the car! and if your wheel baring is bad enough to cause it to push your calaper piston back in enough to require 2 pumps you must be deff because it would be making one helluva noise by that time!

[darkmist2k1]

What haveyou done to your brake system lately, did you bench bleed your mastercylinder when you replaced it?

Dont ask me why I know this but if you replaced the calapers make sure they are on the correct sides of the car! and if your wheel baring is bad enough to cause it to push your calaper piston back in enough to require 2 pumps you must be deff because it would be making one helluva noise by that time!

i never said anything wrong with my wheel bearing.. havent chnage the calipers but i pretty sure they are on their correct sides..

yes i bench bled the master cylinder.. and bled the whole system twice.. still no hope..

[NuwanD]

...and if your wheel baring is bad enough to cause it to push your calaper piston back in enough to require 2 pumps you must be deff because it would be making one helluva noise by that time!

Not true, I've had wheel bearings go with enough play to cause this to happen without making the usual whirring noise, an odd clunk occasionally however. Sucks when it happens on a rally

[darkmist2k1]

so brake booster?? cause it seems like it.. any other sugestions

[ej22t]

The brake booster is the main factor of your paddle feeling. Change the single stage booster and you will find out how liner the feeling it will be and it worth every pennies for the change!

I had my change and now the peddel better then stock!

Ben

[darkmist2k1]

i dont want to upgrade or anything.. i just want iit replace since my pedal is still super soft!!

[Imprezive]

It must be the brake booster.

Do a search, I am pretty sure you can go to a junkyard and pull off a single stage booster.

[Legacy777]

It's not your brake booster.

You've got air still left in the system.

I know & understand you've bled the system twice, however these cars can be an unholy pain in the rear to get air out of.

When you bled the brake system, what order did you go in?

The proper order is RF, LR, LF, RR.

This thread gives some additional information if you have bleeders on the abs
http://bbs.legacycentral.org/viewtopic. ... 326#179326

Secondly, I would recommend slowly but firmly pumping the brake pedal about 20 times, and hold the pedal down on the last stroke. Have someone else open the bleeder, and close the bleeder when the pedal is on the floor. Repeat one to two more times, and then move onto the next wheel.

You can also, and I'd recommend doing the above procedure but with the car running. This will utilize the vacuum booster to increase the pressure in the system and force trapped air towards the calipers.