Drum brake writeup?

nevada said:
yep, that would work. can you get to the ports with that tool, when the mc is mounted?
Click to expand...

I'm pretty sure I'll be able to. The only thing I could see as a potential issue would be the lines being in the way. I'll see what happens. Since I dont have a vice, I was curious what I could do to bleed the MC off the vehicle, using the tool.
 
Easiest way for me is to get some 12-20 inch brake line and screw one end in each port and curl the other ends up over and into the MC resivour down near bottom. Then just pump brakes a little and stop and wait until the air bubbles go away and repeat until no more bubbles are present.

Then remove the short lines from the Master Cylinder and let fluid drip onto a rag while you hook up your brake lines to it.
 
So I went to a friends house who had a vice. I bench bled the MC, installed it, and bled the lines. Took her for a spin and its still the same way, a very soft pedal. If I pump the brakes up until hard and put my foot on it with some force, it will sink down about 1/2 way. On the highway, when I apply the brakes I can feel it "catch" but the vehicle doesnt start to slow until my foots 1/2-3/4 the way to the floor.

We did inspect the rear brakes (no leaks and the shoes look good). We also did adjust them. While this did seem to make for a more noticeable "grab", it still didnt fix the soft pedal.

My only guess at this point is a I have bad brake booster. What else could it be otherwise?
 
When you turn off the 4runner, pump the brake 5 times and hold it. If it remains hard, then booster is more than likely fine.

When you bled the brakes, was there a constant stream of bubbles at any bleeder valve? Sounds like air is still in the system.

How many clicks until the parking brake engages?
 
LittleCaesar said:
When you turn off the 4runner, pump the brake 5 times and hold it. If it remains hard, then booster is more than likely fine.

When you bled the brakes, was there a constant stream of bubbles at any bleeder valve? Sounds like air is still in the system.

How many clicks until the parking brake engages?
Click to expand...

When I pump the brakes up, I put my foot on it and begin counting down from 30. It slowly sinks down to 1/2-3/4 of the way to the floor until about the count of 25 and doesnt move from there.

When I was bleeding, the front passengerside had quite a bit of bubbles, but after several open/close session, no more bubbles (I'd estimate about 5 mins of open, close, pump, open, close...repeat). Other wheels had a few bubbles at first (was just liquid after a couple of open/close), no more than 30 seconds of pump up/open/close.

I'll have to count clicks, but I'd guess 7-10 right off hand.

Edit: I also used the Cardone syringe to bench bleed the MC. But, I never did seem to get all the bubbles out. What I mean is that when I would inject the fluid from the syringe, tiny (super tiny) bubbles would come up. These bubbles were like carbonation (soda) bubbles, not "big" bubbles. I never could get them to go away. Do you think I got a bad MC out of the box?
 
Last edited:
Just wanted to give an update. I have a replacement MC coming to me and also a brake booster (thanks to [MENTION=78895]DeathCougar[/MENTION]). I'm going to replace both next weekend. I will report back.
 
My new MC is here. Just waiting on the brake booster. While looking everything over, I did see that there is a gasket that goes between the MC and brake booster. The one on my runner is completely toasted. Can anyone tell me what the purpose of this little gasket is?

I have one on order for the new install I'll be doing next weekend. Just was wondering what the gasket does, since I've never seen one on other cars.
 
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