Brakes Still Soft After Bleeding

[PrinceYota]

I'm working on a '97 3.4L 4Runner and I swapped out the old leaking brake master cylinder along with new brake pads and rotors for the front and adjusted the rear shoes. I bled the system numerous time starting with Right Rear, Left Rear, Right Front, and finally Left Front. I just used a clear tube and bottle and pumped out the brake fluid for the bleeding method. The brake pedal is still soft. Any suggestions. Bench bled the Master Cylinder prior to installation.

 

[Skidmarcx]

By chance did you closely inspect the calipers and wheel cylinders?

 

[PrinceYota]

yes i did inspect them no leaks.

 

[drabbits]

Sometimes the rear brake drum cylinders can go bad without an apparent leak trail, yet when you push back the rubber cap its obviously leaking OR you simply still have air in the lines. Gotta watch the brake fluid level closely when you bleed old school style.
If you lived closer, I would lend you my power motive brake bleeder.

 

[Ex-ToyTech]

Dumb question but are the bleeder screws on the top side of the caliper? Easy mistake to make when replacing calipers.

Tim

 

[PrinceYota]

Bleeder screws are on top. I will double check the rear cylinders again. I was told that air could be trap in the ABS Modulator and that it needs to be bled with a scanner. Is this true or can it still be bled manually?

 

[LittleCaesar]

Are you bleeding them alone or with the aid of a friend or such?

Also did you bench bleed the MC first before installing it?

 

[PrinceYota]

Yes I bench bled the MC before installing it. I had an assistant to help with the bleeding. I bled it numerous times and there were to signs of air bubbles not even small tiny air bubbles.

 

[Akujin89]

Try Tapping the Master Cylinder with a hammer while a friend pumps the breaks. Sometimes the per-portioning value gets stuck one way even after bench bleeding. Tapping it with a hammer can jar it back into place.

 

[LittleCaesar]

Ever get this fixed? I tried once with a car, bled it six times with a friend. Finally key on engine off worked for us.

 

[PrinceYota]

key on engine off. hmm.. I'll give it a shot. I will attempt to do this again today. what year is your car. I thought you only do that to cars with electronic brake booster

 

[01thunder]

my pedal is a bit soft and the travel long. must i bleed with the key on being that the booster is electronic?

 

[BlackWorksInc]

You may have let air get into the ABS Solenoid pack, in which case you will need to do a bleed/purge procedure to get air out of the system. It shouldn't too hard to do on the 3rd gen, I believe there's a section in the FSM about doing it without a TIS Techstream or the old chipped Tech2 we used before hand.

 

[LittleCaesar]

Getting air into the ABS modular is a PITA to remove on your own. If you have enough of a pedal, try to find a gravel road or such to engage the ABS, then bleed again.

Let the MC go dry during the process?

I have had success with bleeding Chevys and Volvos with the key on, engine off. Never done such on a Toyota, so proceed at your own risk. For $100+ it may be worth it to take it to the dealership (I have done such as well after many failed bleed attempts).

 

[01thunder]

You may have let air get into the ABS Solenoid pack, in which case you will need to do a bleed/purge procedure to get air out of the system. It shouldn't too hard to do on the 3rd gen, I believe there's a section in the FSM about doing it without a TIS Techstream or the old chipped Tech2 we used before hand.

i had the lines pinched before disconnecting from caliper. reinstalled and then let fluid flow with bleeder open so gravity would fill caliper then ooze out bleeder. no brake light on.

 

[01thunder]

Getting air into the ABS modular is a PITA to remove on your own. If you have enough of a pedal, try to find a gravel road or such to engage the ABS, then bleed again.

Let the MC go dry during the process?

I have had success with bleeding Chevys and Volvos with the key on, engine off. Never done such on a Toyota, so proceed at your own risk. For $100+ it may be worth it to take it to the dealership (I have done such as well after many failed bleed attempts).

MC was not dry. no fluid loss until bleeding. i don't have a FSM so i don't know if it is normal or is it just me thinking it is bad. the brakes grab and grab well. like i said, i bled and little air came out of both calipers, nice stream on both.

 

[PrinceYota]

I noticed there is a screw at the end of Master Cylinder. Can I bleed from there to get any air trapped in there out.