Brake pedal goes all the way to floor, etc.

[ThePizzaGuy]

I was finishing up my rear axle seal job today, and put new brake shoes on the rear while I was back there, and now I'm having an issue with the brakes. We bled both the rear brakes multiple times after reassembling everything. Master cylinder never went dry.

I had normal pedal travel and pressure when I started the job. Now, on the first pump, the pedal travels the full distance. After pumping multiple times, the pressure will build for a moment, but will slowly release, and the pedal will drop again. What did we do wrong?

 

[BlackCat914]

 

[kball]

What did we do wrong?

Maybe nothing. After messing with brakes it's common for the peddle to have extra travel at first. Should snug right up after that but I've read on here multiple times about still having mushy brakes until you make the ABS activate. How do the brakes feel when you drive it? Does the peddle stay firm then or still sinks?

 

[nissanh]

I do not think it is the ABS. I have replaced the rear brake hose and in few pumps (brake bleeding) everything came back to normal. Try this, use about 200 ml syringe and a hose that fit into the bleeding nipple and to the syringe. fill the tank full and slightly loosen the bleed nipple and pull oil from the syringe. After pulling about 300 mL, you can bleed manually. Once probably is enough.

 

[Buckaroo]

The rear brakes are drum brakes. They need to be manually adjusted so that the shoes drag slightly against the drum when the brake pedal is not depressed. If the shoes are too far from the drum, then you will have too much freeplay (i.e the pedal will sink too far) when depressed. The front disc brakes will self adjust (i.e. upon repeated application of the brake pedal, the pads will move towards the disc and the pedal height will return to normal). For drum brakes, however, that is not the case. They must be adjusted manually.

Good luck,

 

[ThePizzaGuy]

Thanks all for your advice. We also tried replacing the master cylinder and bled some more, thinking the piston may have a leak, but to no avail. The pedal still goes all the way to the floor before really beginning to engage, when driving and while on the lift.

I'm going back to the garage tomorrow to work on it some more. We'll check the adjustment on the shoes again, but I'm pretty sure we've got them backed out until we get friction on the drum. Also, I've now been told by my mechanic friend that driving in reverse and then engaging the brakes will cause the screw to self-adjust? If that doesn't help anything, I think we'll try the syringe method nissanh mentioned.

Going in to work now, but I'll have some (hopefully successful) updates tomorrow.

Thanks again,
Rick P

 

[LittleCaesar]

Do you see bubbles in the fluid at any of the bleeding nipples?

Feel any drag on the drums when you put them back on? You need to feel a little resistance, or you can count on them not being adjusted out far enough.

To adjust rear brakes, I use a short stubby screwdriver on the adjusting star wheel (I believe downwards) while pushing out the kickdown plate all through the adjusting hole. You can feel the shoes begin to contact the drum while moving the adjusting star.

Then travel to a hill. Put in N and pull on the emergency brake. 4 to 7 clicks of the emergency brake to stop the 4runner means they are adjusted correctly.

And for this type of drum brake, going in reverse does nothing for adjusting the shoes.

 

[shootmymime]

yeah your pads arnt making contact with your drums. there is a plug on the back of the dust shield that makes u able to adjust the pads after the brake job. also check your parking brake. ill bet cha thats loose.