Hard pedal

[desertmonkey]

The old master cylinder leaked into the booster and now both are ruined. I purchased a reman booster and master cylinder and forgot to remove the

spacer from the old booster. Once the two parts were on the car we have

a hard pedal and squealing front brakes. My vacuum gage shows a steady

19 inches at idle and no change when braking. It seems that I am using

the master cylinder and not getting any booster action. I have two new

check valves and hoses and no apparent leaks. The system was powerbled

and when I tested the booster with engine off and restart the pedal did not

move.

[nizm0zed]

[luvemfast]

What's the problem? 

Sounds like the calipers are the culprit by your description.......  :-\

[DAZDA]

and forgot to remove the spacer from the old booster.

 

Does this mean you haven't put the spacer in??  Maybe you should do that.    NOTE: Not having it in there may have damaged the diaphragm in the booster...

 

OR

 

If you are sure you're getting a vacuum to the booster (as below would suggest), and everything has been installed correctly (as per the factory manual)

 

My vacuum gage shows a steady 19 inches at idle and no change when braking. It seems that I am using

the master cylinder and not getting any booster action.

 

Then the remanufactured booster may not have been so well remanufactured...

[desertmonkey]

Tomorrow I will get another booster and test it off the car but I have no spacer so I may have to manufacture one somehow. Perhaps I can come up with some aluminum stock and make one.

[desertmonkey]

bolt on spacer for brake booster to firewall on datsun 260z Google Images on page 3 shows two boosters and one has a spacer. Do I need that spacer for a proper installation?

[Riceburner]

Without the spacer plate the booster pushrod will already be pushing on the master cylinder? Fit the plate, measure how far out the booster pushrod is on your old one then match the new one to it.

 

You should be able to test the booster by running the engine then shut it off, disconnect the vacuum hose and you'll hear it suck if it's pulling a vacuum. Is the check valve ok in the booster hose?

[Wayne G]

is the check valve in the booster hose the correct way around? IE.  the engine can actually create a low pressure in the booster?

[desertmonkey]

The new booster works and so does the check valve but now it feels like the fronts are dragging at times. I did not adjust the rod to the M/C and the rod to the pedal

has roughly an inch play before the brake lights go on. When I pump the pedal with

the engine off I feel it stiffen and hold pressure. After I start it up she goes down about 6 inches and I hear the squishing sound from the booster not a hiss. Perhaps

I just need to recheck my settings after I take a run around the area.