no brakes

[rezdiver]

1991 l300.

the brakes used to feel a little spongy for a while, today all of a sudden, no brakes.
took all the wheels off and checked for leaks and while i was at it i replaced all the front and rear pads and shoes.. still no brakes.
checked the reservoir and its full. i can pump and pump and pump it, the level drops and comes back up after a short time.
engine off, i get some resistance, engine on=zero resistance to the floor. i can pump it a bunch of times and the ebrake warning light comes on and goes away once i stop. i can see the fluid level drop as i pump and comes back to max level when i stop.


i thought the master cylinder may be shot but i cant see any leaks. and there is no loss of fluid that i can see.

the old pads and shoes were worn to around 25% all the way around, is it possible that because of the wear the pistons pushed out far enough for air to get into the master cylinder causing the loss of brakes...? i never added any fluid once i replaced the brakes so pushing the pistons back in may have brought the level back to normal.

is there a procedure to bleed the master cylinder?

[Luna-Sea]

Hey,
Have you checked under the floor mats by the pedals to,that is where I had
a leak show itself.
The light is a shared parking brake/brake problem light.

Are you sure you are not loosing any fluid?

Is it an Auto or a 5 speed?

To bleed it is just like any other vehicle except maybe easier
because your brake job buddy that will be sitting in the driver
seat pumping the brake for you can see the fluid level easily.
(another of his/her jobs is maintaining the fluid level topped up,
so it does not suck any air into master cylinder and make you have to start the whole process over again..)
Get lots of brake fluid and give it a good rinse through until the fluid is nice and clean.

this is while you are under the van of course thoroughly enjoying the
thrill that is burping brake lines.

Also failed master cylinder will not always leak in a way you can see easily.
So just want to make sure you parking brake is in good working order too.

Hopefully is just some air in the lines,
Have you done a brake job before?

Good Luck!

[legionnair]

The master cylinder has two types of seals external seals to keep fluid in and cups seals or also called the pistons, here's a little test pump your brakes to stiffen the pedal then push and hold the brake pedal. This takes a bit of time. If your pedal stays firm then the master cylinder is most likely fine and it just needs a bleed

[Artacoma]

When my brakes failed on my L300 it was a bulging brake line that puffed like a balloon , there was no loss of fluid at all.
I made it to a Midas using my hand brake and a couple of hrs later they had a new line installed no problem.
It was around $150 I think. Just asked them to cross reference to a Montero.

good luck

[rezdiver]

Bled the brakes this morning and they are good to go.

there was a ton of air in the lines. i am surprised that at near 25% material left all around was enough when the pistons pushed out to drop the fluid level and let air into the lines. i had checked the fluid level a couple of weeks ago and it was between min and max.

felt a bit silly looking for the left rear wheel bleeder for a few minutes before realizing that there is no bleeder and it just loops back to the right rear wheel bleeder.....