Bleeding Brakes on 3rd Gen not working - need help
 

I just did a massive brake job on my 4Runner, replacing all of this:

1. master cylinder
2. rear drums and shoes
3. rear cylinders
4. front rotors and pads
5. and flexible brake lines with Wheelers Off-road lines
6. plus replaced all the bleeder valves.

I bench bled the master.
I have bled the whole system 3 times now always starting with the passenger rear, then driver rear, then pass front, ending on the driver front.

After all this... My brakes are spongy!

When I press down they are "slow". It feels like there is air in the line that I'm trying to compress down and then the truck comes to a stop - but not immediately. I am just rolling down the street at about 15 MPH and its slllooooww to stop. For example, when I drive my Nissan Maxima, the brakes are snappy and tight. As soon as I give them a press, they grab! NOT so in the 4Runner.

I used the Maddox Dual Vacuum/Pressure Hand Pump Kit, purchased from Harbor Freight. It holds a vacuum no problem. On the last bleed, I watched bubbles coming out then I got solid brake fluid.

Does anyone have any suggestions or tips?
Does the ABS have anything to do with my problem?

I watched Timmy's video to make sure I did it right...
Brake Fluid Bleed/Flush - YouTube

The only difference is my 1998 4Runner doesn't require the key to be in the ignition to activate the brake booster.

What year rig do you have?

Could be possible there is some bubbles trapped in the ABS. From I read, it seems some individuals try to activate the ABS a few times to push some of the bubbles out, then re-bleed.

Order some speed bleeders, they worked really good when I used them.

Speed Bleeders
 

I just installed these:

Russell 639580 Speed Bleeder

1998 4Runner
 

I have a 1998

How much fluid have you ran through the system? With all the components you replaced, I'd assume your lines were pretty dry unless you capped them off with vacuum caps or something similar. It might just be the fact that you haven't gotten all the air out. The fluid has to travel a decent distance from the front to the rear so there might be some air trapped in those lines still.

I would say if you haven't gone through at least 1 quart of fluid, you need to keep bleeding.

Starting with the passenger rear like we show in our video and just keep bleeding that wheel cylinder over and over again. Do it a lot and then do it some more to rule out that's there's some air trapped between the front and the rear. Then go to the driver rear and bleed it a bunch of times but you won't have to do it as much because you already moved a ton of fluid to the passenger rear. Bleed the fronts a bunch of times too, but again, you shouldn't have to bleed them as much as the rears since the fluid have less distance to travel.

Another thing I have to ask is did you adjust your rear brakes correctly by pulling the e-brake over and over again until you only get around 7-9 clicks from the brake lever? Rear brakes that are way out of adjustment will dramatically affect your braking strength.

Let us know how it goes.

What @mtbtim - check the rear brake adjustment.

Does your e-brake work?

I couldn’t get my brake pedal to feel right and couldn’t stop for crap after my last brake job. For me pulling the e-brake over and over to adjust the brakes does nothing and my e-brake wasn’t working.

So I chocked the front wheels, jacked up the rear end, and took off the rear wheels, then took off the brake drums. There’s a manual adjuster there and I used a screw driver to push it down a few clicks at a time, then tested my e-brake each time. Once my e-brake was firmly working on both rear wheels I put it back together and the brakes work much better now.


Sent from my iPhone using Tapatalk

You probably emptied the ABS unit.
Drive on a dirt/loose gravel road and "CHECK BEHIND" and when no one is there, slam on the brakes to activate the ABS system (must get the wheels lock to activate the ABS). Bleed the system. Do it once more on the dirt road and bleed again.

I've seen this happening on most toyota's with ABS system running dry.

Alternatively, you can take it to the dealer (NOT advised to drive on the road) and they have an electronic tool to activate the ABS to bleed the system.

I've never emptied a system enough to have something like this happen. So, the only way to bleed the ABS system is to get it to activate, which I guess allows fluid in and pushes air out? Interesting. Is this covered in the FSM?

When I first got my 97 project on the road I had to replace both front brake hoses. They were both cracked pretty bad.

Braking hard in the rain activated the abs and my pedal instantly went soft. So I bled them again. It took three rounds of bleeding and abs activation until my pedal didn’t change after an abs activation.


Sent from my iPhone using Tapatalk

Hi Tim!
 

Yes correct.

For the same reason, I will never let the fluid to empty completely and get air trapped inside the ABS unit.

I too learned this on ih8mud.com LC 100 series forum. There are many having the same problem and the experts ln LC 100 are suggesting what I said.

Other possibility you got a crap rebuilt master cylinder and need to get another. Bad remans. happen all the time and will drive you nuts.
There is no special procedure to bleed the ABS, even if you replaced the ABS actuator you just follow normal bleed procedures, the fluid goes through it with any air.


Here is TIS procedure... I highlighted an important part red.

BRAKE FLUID BLEEDING
HINT:
If any work is done on the brake system or if air is suspected in
the brake lines, bleed the system of air.
NOTICE:
Do not let brake fluid remain on a painted surface. Wash it
off immediately.
1. FILL BRAKE RESERVOIR WITH BRAKE FLUID
Check the fluid level in the reservoir after bleeding each wheel.
Add fluid, if necessary.
Fluid: SAEJ1703 or FMVSS No.116 DOT 3
2. BLEED MASTER CYLINDER
HINT:
If the master cylinder has been disassembled or if the reservoir
becomes empty, bleed the air from the master cylinder.
(a) Disconnect the brake lines from the master cylinder.
(b) Slowly depress the brake pedal and hold it.
(c) Block off the outlet plugs with your fingers, and release
the brake pedal.
(d) Repeat (b) and (c) 3 or 4 times.

Then:
3. CONNECT VINYL TUBE TO BRAKE CALIPER OR
WHEEL CYLINDER BLEEDER PLUG
Insert other end of the tube in a half−full container of brake fluid.
NOTICE:
Bleed air of the rear brake first. If front brake is bled first,
rear brake air cannot be bled.
4. BLEED BRAKE LINE
(a) Slowly depress the brake pedal several times.
(b) While an assistant depresses the pedal, loosen the
bleeder plug until fluid starts to run out. Then tighten the
bleeder plug.
(c) Repeat this procedure until there are no more air bubbles
in the fluid.
Torque: (bleeder plug)
11 N·m (110 kgf·cm, 8 ft·lbf)
5. REPEAT PROCEDURE FOR EACH WHEEL
6. BLEED LSP & BV

Here is the above instructions in image form that should work on the '96-'00 4Runners:

https://i.imgur.com/BFS1dvk.jpg

And yes, getting the bench bleed on the master correct is necessary. It has a balance system in it that is required to get the front discs and rear drums to play nicely together.

You may also have some air in the ABS system that needs to be removed.

I'm in the middle of a brake bleeding saga myself. My brakes are back to about 80% of where they should be after a new master cylinder and Tundra front brakes. Need to re-bleed to get some air out of the ABS system at the moment.

-Charlie

Do you have a pressure bleeder?


Sent from my iPhone using Tapatalk