brake question (1 Viewer)

[Man Jerk]

Brake question for you guys.

My brake pedal is spongy. I can and do pump it a couple of times and it gets firm. I've replaced every brake component on the front axle except the rubber brake lines. Haven't touched the rear except the main line that runs down the frame was replaced, and everything was blead.
My thinking leads me to think that it may be my master cylinder. Can anyone give me any ideas how to test the MC, or other items to check?

TIA

 

[bad_religion_au]

have you adjusted the pushrod from the back of the pedal into the boost/master cyl.

my master when leaking left brake fluid down the firewall, so i don't know of any tests, although i recall something about pumping it up to firm on a hill and keep constant pressure on it, if you start rolling without releasing the brake, you got a leak somewhere.

you might want to check the rear slave cylinders in the drums for leaks too, and adjust the f#$$ out of the drum brakes on the rear (front too if you got them but i assume it's the 60 in the pic)

are you loosing any fluid?

 

[offcamber40]

I had the same problem in my 40. Turns out the the adjusters werent self adjusting. Like bad_religion said, try adjusting the rear brake pads/slaves.. it might just do the trick.

 

[Man Jerk]

To adjust the wheel cylinders do I just have to turn the star wheels behind the backing plate?

 

[offcamber40]

Yes, use the tip of a screwdriver. I forget which way pushes the pads out, but turn the stars until the pads drag on the drum, then back them off until they dont scrape anymore. Hopefully that takes care of your squishy pedal.

 

[hammerhead]

The Toyota book says tighten until "adjuster nut cannot be turned further". Then back them off 4 or 5 notches to "retract the shoes until the wheel can be turned lightly".

 

[DenverCruiser]

I had the exact same problem. Adjusted the drums all around and all fixed. I bet this is your problem since it is firm after pumping.

 

[Man Jerk]

Totally fine after adjusting the rear drums. Thanks for the help guys.