Major brake issues, prob simple just to blind to see it

[Ekimrm]

Let me try and explain this the best I can. I have picked up a 1990 4Runner to restore. It is in rough shape but fixable. I decided that I will change the brakes, should be a quick 30 minute job. It has been 3 days. First off the caliper on the driver side was frozen. It would not move. so I replaced the calipers on both driver and passenger side. I replaced the brake pads and the metal line that goes from the rubber line to the caliper. I installed everything. Then bled the brakes. The brake pedal goes to the floor. So I have bled and bled and bled some more. There is no air in the line and no leaks. There is plenty of brake fluid. To do a test I clamped both rubber lines off and the pedal is hard as a rock and stays that way, that should eliminate the master cylinder as being the problem. I take one clamp off it is still hard, but will eventually seep down, it doesn't matter which side either. I noticed on the master cylinder the previous owner has the back brakes undone by putting a plug in it so that isn't the issue. The brakes worked up until I changed them. I have ran out of ideas on what to try next. Can someone please help?

 

[20034RunnerV84x2]

You've got me stumped too!

Are all of the vacuum lines properly connected and not leaking?

 

[77'911]

You might consider getting someone to help you pressure bleed the brakes out. Those calipers are a bear to get all of the air bubbles out. I would flush out all 4 corners.
regards

 

[SV_Dude]

I would agree, you still have air in your calipers. Bleed more If you still have issues take your runner to a shop and they can hook your brakes up to a machine and cycle fluid through it to be 100% sure that there isn't any air in the system.

 

[Hyde802]

I agree with 79'911. Need to bleed all 4 corners. And the LSPV if its still there.

 

[Gerdo]

Bleed, bleed and bleed some more.
As you are bleeding, tap the caliper with a dead blow hammer. This will dislodge air bubbles inside the caliper.

 

[the_dingman]

How are the rear brakes? If the rear is not getting pressure, the pedal will go to the floor before barely applying the front brakes.

The brake system on these trucks needs to be bled in a specific order... I don't recall what it is. I know the proportioning valve is first, then the rear, then the front, but I don't recall which side is first.

 

[DC runner]

Order is usually "furthest out to closest in from brake booster". So, if the master cylinder is front driver's side, then you would start with rear passenger, then passenger driver. Move up to front passenger, and finish with front drivers.

 

[Ekimrm]

Coming out of the master cylinder the previous owner has a plug in it so the backs are not hooked up. I think I know what I did wrong. I just learned that the bleeder valve has to be on top and I have them on bottom. My mistake I guess. I will try it tonight and let you know.

 

[DC runner]

What is your technique for bleeding?

 

[Gerdo]

so the backs are not hooked up. .

I think you need to hook up the back brakes once you get this part worked out..

For bleeding did you... with the bleeder valve closed, pump up the brakes, hold, release the valve, tighten the valve and repeat?

 

[DC runner]

Yea. While the front's do about 60-70% of the work, it is dangerous to drive around with any rears. Not sure where you live, but I also daresay illegal. If you needed emergency stopping power, it wouldn't be there. That rear 40% braking power is the difference between hitting something and not.


Also. You will have to re-bleed the entire system once you install the rears.

 

[Levinz11]

The front and rear brakes are connected. One line goes from the MC directly to the back. Another line connects the front circuit to the LSVP in the rear. You'll need to get all four corners going to fix it right.

 

[mikedks]

I'm stumped as well, I mean I always ghetto bleed my brakes because I work alone. Pump it up, cinder block on the brake pedal, bleed, make a mess, repeat.
Usually get a pedal pretty quick, can't for the life of me figure out what's going on. Maybe the issue with the back brakes?

 

[Clone of the Mean]

This may be a bit of a stretch but a few years ago ago my friend converted his blazer to rear disc brakes. He ended up putting the passenger caliper on the driver side and the driver caliper on the passenger side. They were upside down and we bled them for a whole day and two gallons worth of brake fluid.....

Kind of an easy mistake to make on a chevy, dunno about a toyota. Good luck.

 

[Ekimrm]

I got them fixed. You have to have the bleeder valve up top. I had them on wrong. After I switched them it took 5 minutes to bleed and make them right. My back brakes are what is next to tackle.