Power Brake issue, ideas? (1 Viewer)

[abosely]

Yesterday we parked our 87' FJ60 all was good.

Went back 45 min later and had no power brakes, drove a few blocks stopped, shut off motor.

Started up, drove a few blocks again no power brakes.

Stopped again, got in and power brakes worked fine!

To day drove around brakes worked fine while driving home, power brakes quite.

Brakes work just no power brakes.

I looked around the vacuum booster and all looked fine.

I am at a loss, any ideas or where to start looking?

Allen

 

[Lost]

1 look at ALL brake lines for wear/rust/corrosion
2 bleed the brakes, dont forget lspv if you have rear return lines

when the booster leaks it usually pin holes on the inside...

corroded lines might look ok, but the rust just hides any holes.

applying excessive presure on the hard line (ie hard stop on the street) might expose an unseen leak.