Spongy brake pedal (1 Viewer)

[David*BJ70]

Hi every one. I think I have the answer for this one but I need, maeby other opinion...

So my brake pedal is spnongy. Almost every firt push I feel it spongy, so now I always push two quick time on the pedal.... And the second push on the pedal I feel it correct. I always work very good after the second push.

So I believe the problem is my brake master cylinder.

Is someone have other opinion on this ?





I already read the old 4runner caliper can fit on a BJ70... what else ?

Thank

 

[wesintl]

The brakes are vacuum assist so you might not have great vacuum in the system on the first push. Otherwise it's a bad master or air in the system. If you just installed a lift the rear proportioning valve isn't adjusted correctly.

 

[David*BJ70]

No lift.

Vacuum, vacuum... I read also a bit about this, but no so familar. How can I first know if is my vacuum?

After, I will go for my master.

PS : Nothing about the vacuum in the brake section in the manual...(?)

 

[Greg_B]

Hi David

There should be mention of the vacuum test in the manual. Put foot on brake pedal, start the truck. You should feel the pedal sink slowly. If so, vacuum working. You can also pull off the vacuum line at the can and see if there is vacuum there. You will hear the air rush in, filing the vacuum...if your vacuum pump is working and the system is also holding the vacuum.

hth's

gb

 

[lowenbrau]

Check your wheel bearings. If one is loose it allows the rotor to tilt slightly in the caliper and requires a pump of the peddle to straighten it up before getting good brakes. Just jack the front end up and wiggle the wheels one at a time. If they move up and down as well as side to side the wheel bearings are loose. If they only move up and down but seem ok side to side its the knuckle bearings (won't affect brakes).

 

[David*BJ70]

With your comments, I' m all set!

Thank

 

[Greg_B]

Just to make sure the basics are covered:

There is brake fluid and the rear brakes are adjusted and all brakes are in good order?

gb

 

[David*BJ70]

Just to make sure the basics are covered:

There is brake fluid and the rear brakes are adjusted and all brakes are in good order?

gb

I think so... ... yes

 

[Diescipel]

Right I was thinking rear brakes not adjusted--first push expands the wheel cylinder, second engages the shoes.

B

 

[rat]

Forgive me if this is dumb advice: I've read that poor quality steel brake drums can be a problem on some Cruisers - they 'give' under the stress of the shoes. I have OEM drums on mine - my brakes are still soft. I've wasted gallons of brake fluid bleeding the system. New brake shoes too. Vacuum is strong. No leaks. Someone suggested steel braided brake lines may help - rubber hoses expand under pressure apparently. I don't know.... guys from the cruiser club here say cruisers have poor brakes...got to live with it

 

[bigbrowndog]

Any chance your back brake drums have worn well past their maximum wear limit. The newer hj75 series wears pretty quick in sand, no where as hard as the old rear drums. If the booster is not working correctly the pedal should be harder,spongy sounds like air.Did you bleed the load proportioning valve as others suggested.cheers

 

[Eric Winkworth]

I disagree cruisers have great brakes if well maintaned!!

 

[Ratpuke]

Hopefully your rotor no looky like this:

 

[lshobie]

wow - now that is toast!

 

[wesintl]

whoa! :whoops:

 

[drexx]

The brakes are vacuum assist so you might not have great vacuum in the system on the first push. Otherwise it's a bad master or air in the system. If you just installed a lift the rear proportioning valve isn't adjusted correctly.

I 2nd this great advice.