80 series brake troubles (6 Viewers)

[Hazz80]

Hey guys just wondering how we are all bleeding our brakes because me and my dad did it by cracking open the furthest away bleed screw (passenger rear). and then bleeded our way towards the closest one and still found my pedals to be mushy/spongey. Would harden if u kept pressing them but leave it for a minute and would go straight to the floor. We did replace the valves inside the master cylinder along with the rubbers for it. Unsure of why this is not working but also notice inside the cab when you brake you can hear air escaping???. Heard that it may need to be pressure bleed and at the moment this is our next step we are gonna take. If u have any ideas on how to pressure bleed please send them. This car is my daily and really need it back on the road

 

[Malleus]

If your brakes are soft or spongy, you have air in the lines. There's no way around this, this is how hydraulic brakes work; air is compressible, hydraulic fluid is not.

I use a pressure bleeder to maintain pressure to in the lines while I bleed the system. Anything, including a homemade job, will work, just be careful not to exceed 15-20–psi.

If you have a LSBPV, it may be leaking internally. When you bleed the rear brakes, bleed this valve before you bleed the fornt calipers. You have to actuate the valve, moving the sense rod up and down, in order to bleed it properly. I always check the rear calipers again, after I bleed the LSBPV, just to make sure air didn't get downstream after I bled it.

If you're hearing air hiss while you're in the driver's seat, your problem may be near, or in, the brake booster. There are troubleshooting procedures in the srvice manual for this, so I won't reproduce them here.

Above all, don't give up. The 80 had solid brakes when it was new, and if the braking system is correct, it will again.

 

[lumbee1]

If your brakes are soft or spongy, you have air in the lines. There's no way around this, this is how hydraulic brakes work; air is compressible, hydraulic fluid is not.

I use a pressure bleeder to maintain pressure to in the lines while I bleed the system. Anything, including a homemade job, will work, just be careful not to exceed 15-20–psi.

If you have a LSBPV, it may be leaking internally. When you bleed the rear brakes, bleed this valve before you bleed the fornt calipers. You have to actuate the valve, moving the sense rod up and down, in order to bleed it properly. I always check the rear calipers again, after I bleed the LSBPV, just to make sure air didn't get downstream after I bled it.

If you're hearing air hiss while you're in the driver's seat, your problem may be near, or in, the brake booster. There are troubleshooting procedures in the srvice manual for this, so I won't reproduce them here.

Above all, don't give up. The 80 had solid brakes when it was new, and if the braking system is correct, it will again.

i will add that I also use a Motive power bleeder with the Toyota adapter. the ABS pump can also get air inside of it and cause spongy pedal.