Brakes...Still spongy

[PurpleFJ62]

Hi All,
just finished doing some testing on my brakes. Bled at all 4 corners and at the LSPV. Have correct amount of brake fluid. So next I checked for vac. leeks. The hoses were fairly rotted. So I got 4 feet of hose and made a new system, using some 3/8 tee fittings. Anyways I was getting pretty excited because I really though this would fix the problem. Well it did not. Anyone have ideas about testing the master cyl or the black bowl looking this. I call it a Vac. Canister, because I have been lead to believe its under vac.

Anyone had similar experiences?

-nate-

 

[RredFJ40]

Uhh, what kind of hose did you use? Brake hose isn't just something you can pick up at home depot. I'd bet your sponginess is from that hose swelling under pressure. Brake line is very rigid and resistant to swelling, it isn't just rubber hose.

 

[ellington12]

purple,

are you saying you redid the vacuum plumbing to the brake booster, (the big black thing?) if so this is ok but if you made actual hydraulic brake lines, this is NOT GOOD.

misadjusted rear drum brakes can cause a weird pedal.

 

[mtb_rider]

Is your rig lifted? If it is, did you move the LSPV up the same number of inches as the lift? (If that makes sense)

 

[roscoFJ73]

The black bowl is the brake booster(vac canister is what diesels have and it sits underneath the booster sometimes)

The basic test for the booster is to press the brake pedal a few times until the pedal is hard and all the vac has gone (engine off)
Then put your foot on the brake and start the engine. You should feel the pedal sink a little as the vacuum takes affect.

To test the MC you just put your foot on the pedal and see if it holds pressure.

Now these rubber hoses you replaced. If they were the ones to the calipers and drums you need special brake line hose.
Brake booster hose needs to be vacuum hose that wont crush.

As ellington12 said you need the rears adjusted properly otherwise the shoes expanding and not touching the drums will give a misleading spongy feel