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brake pedal disconected

iviper123

iviper123

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north Branch, MI
ok, so while out tonight my wife lost the brakes on the truck when the tow truck got it home (after dark of course) i look the push rod from the brake pedal to teh firewall/master cylinder was jus hanging freely not connected to the fire wall in any way, anyone have pics or a diagram of the area and what could have happened to cause that?
 
Why was it towed? The tow truck driver might have installed a strap from brake to steering wheel that pulled the brake pushrod out of the booster because the booster was depressed. More likely if it was a cable wrecker that towed from the rear bumper or wheel lift ???? If on top of a rollback there is not the need for steering wheel lock strap.

The push rod is part of the hydroboost and is in a ball socket joint. The booster pushes the brake pedal back up if I remember correctly. If the brake pedal is pushed more than 3 times with engine not running the booster doesn't really give much resistance to brake pedal and it can sink low. Might have been down when strap pulled the brake pedal up. Maybe look at leak in brake system that allowed hydroboost and master cylinder to stroke to floor and want to stick. Brakes usually only strokes a little ways but in an old worn system the rest of the stroke can build up corrosion and or crud.
 
Leaking brake line won't cause the rod to come off. Most likely is the clip that hods rod to pedal came off or never was put on/back on? Its unlikely the ball and socket side of the rod (wore to the point it could pop out), but check that out also. Reach up there and pull the rod as far back as you can, if it comes out HB need R&R. Visually inspect it also. Look to make sure rod is on pedal and clip is installed.
Nothing to take chances with, make sure it right before sending the truck on the road.
 
I don't think a little leak, seepage, or even a bad wet leak would cause the hydroboost rod to fail. I assume it would be a catastrophic failure that allowed a sudden movement of hyrdro boost /master cylinder stroke. Its usually in a bit of compression pushing against brake pedal and keeping brake switch off and stays in compression when you press the brakes then pushes back the pedal when you release.

My hydro boost just started leaking and what I have read many others do. Some rupture the accumulator. I would check power steering fluid and accumulator real good.

Are the rotors warped causing brake pedal bounce/surge? Was she braking hard and the antilock pulsed the brakes etc. Not sure what all else would stress the hydro rod. It usually sees a pretty easy life I would say. I agree it is a safety issue and not one to guess about. If the rod is still attached to brake pedal but not at firewall I'd probably install a new hydroboost and inspect all the brakes. Probably flush the system etc etc .

Again maybe if the brake pedal was nearer to the floor than it previously had been maybe fluid was low ???? The extra stroke of the hydro and master cylinder might have gotten much farther in bore than usual and been slow to return up and the pedal wanted to pendulum away just a bit and the rod fell out. Hard to say with out being there its suppose to stay connected but as you know with the age of these trucks all bets are off.
 
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