Vacuum Brakes

[87TIGN]

Ok so I had the common problem with the Hydroboost failing on my 87 GN and I didnt want to shell out $1200 for a reman unit so I got a brake pedal setup from an 87 Carlo and I bought the vacuum booster and master cylinder new for an 87 Carlo. Problem is the brakes feel a little soft and it wont hold much boost on the line. I did a brake flush and there is no air in the lines however the only vacuum line I could run was a 3/8 hose and I know I need a bigger hose. What have some of you guys done in order to get a good vacuum draw on that booster? A seperate vacuum pump? Electric setup? I know there are not any plugs on my manifold I can draw from so any suggestions would help.
Thanks
-Andrew

 

[gnloyalty877]

I used a 3/8 inch hose too and thats just how those brakes are suppose to feel like. Did you use the tta vacuum block on top of your throttle body? My advice would be to get one of these FULL THROTTLE SPEED - IGNITION UPGRADES

Do a search for this to find out what it does.

 

[Nick Micale]

If the brakes are soft and not holding, it is NOT a vacuum problem. Sounds like you do have air in the system, and/or your shoes/pads are worn or bad.

A flush will not help. You need to bleed the system properly, ESPECIALLY the master cylinder.

The vac conversion will work fine without the TTA vac block if you use the proper hose and fittings to tee into the PCV line.

 

[87TIGN]

If the brakes are soft and not holding, it is NOT a vacuum problem. Sounds like you do have air in the system, and/or your shoes/pads are worn or bad.

A flush will not help. You need to bleed the system properly, ESPECIALLY the master cylinder.

The vac conversion will work fine without the TTA vac block if you use the proper hose and fittings to tee into the PCV line.

What do I need in order to correctly tee off the PCV so I can use a larger vacuum hose and see if the system just needs correct vacuum? I made sure that the master is completely bled and the lines are free of air.

 

[POWERBRAKEBOB]

master cylinders

the Powermaster used a 1.250" piston. The monte Carlo uses a 24mm piston (15/16" ) Big difference. That's why the different pedal ratios. We use a 1.125" piston on Hydroboosts