Took my 81 for the first spin of the year the other day. Haven't had an opportunity before that. I wanted to see if others with an HB system ran into any of this:

- There is almost no play in the pedal when the motor is off. Pedal is solid as a rock but will give a little if pushed hard and the brakes do work.

- If moving very slow and touch the brakes, they grab, but do not immediately release. It takes a moment. Like when backing out of the garage. Almost like a little drag for a second or two. You don't feel this when moving fast.

- At speed and hitting the brake, car stops on a dime. This of course, is good.

- The one "issue" that bothers me a little and I'm not sure if something is wrong is that if I really put my foot into while moving and hold the pedal down coming to a slow stop, I feel a little rumbling in the pedal and I hear a little whine or almost a moan coming from under the hood. I'd like to think it's plumbed correctly or wouldn't work at all and I've gone over the lines multiple times following the diagrams. I was thinking maybe even belt slip from the 108" serpentine under pressure but it's hard to diagnose as it doesn't do it sitting still.

Has anyone else had any of these issues or is this normal operating procedure?

Thanks...

 

The biggest issue is wether that master cyl is allowed to come all the way back to neutral and releases the brakes entirely....is the car can roll outta the garage like mine, it's fine....you can jack up and feel the brake drag, IF you don't have any springs behind the pistons and/or have O ring pistons...you should be good to go....make sure the brake pedal has plenty of slop in it too....not being forced up higher against any stop....

personally, I LOVE the HB feel.....

 

I had the same phenomena on my first test drives. The momentary brake dragging (after releasing the brake pedal) does go away but it takes some driving, maybe a few hundred miles. I read somewhere (must have been Hydratechs forum) that this is because it takes a while for the new unit to loosen up a bit and to get all the air out of the system.

 

i have the same feeling! (hydroboost has just been installed)
in the begining i belive my brake where locked

 

Hey Jerome, how that drive shaft work out???

hope it fine for you too.....shipping was a bear...no??

GENE

 

It's normal when you turn the engine off for the first brake application to be normal and subsequent applications to be rock hard. The first application empties the accumulator.

You may have a little air left in the hydraulic system. The whine or moan you hear is probably the PS pump. It takes some time to get all the air out of the system. You might try the bleeding sequence again. Also, start the car, open the power steering pump reservoir and have someone apply the brakes while watching the fluid level in the reservoir. You'll be surprised at how low the level goes. If it goes too low some air can get sucked in the system.

 

That's interesting and something I forgot about! I didn't have the noise until I just swapped out the rack over the winter because I felt the one I had in there had a little too much play in it. Obviously all the fluid was drained out. I refilled the external resovoir but did not check it after driving the car. I'll bet I top it off and it quiets right down.

Thanks all for the input.