hi all im new on here so firstly, hi
i just bought a 79 stanza and am having trouble with the brakes
the pedal is really hard to push down and the braeks are qiute innefective youu really hAVE to smash the pedal to get it to pull up....slowly
feels like its a booster problem like there is no vac assist or something, iv checked the vac line to the booster and it looks ok, car has been sitting for years previously nut the disks arent rusty or anything so im thinking booster?
any ideas?

there should be a one-way-valve somewhere in the line between the manifold and the booster, make sure it is the right way round so the flow is towards the manifold.
flush and bleed the brakes

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1979 Datsun Stanza Coupe
1979 Datsun Stanza Coupe Project
1979 Datsun Stanza GX
1982 Datsun Stanza GX
1966 Nissan Cedric Custom Six
1972 Volkswagen Beetle
1974 Toyota Landcruiser Stallion (SWB)
EziAutoParts

no valve that i can see...
could the large valve overlap of the cam be the cause of low mainfold vaccumm?
surely there would be alot of ppl in the same boat then, i dont reckon many modded dattos use OEM cams,
anyone use a vac accumilator?

You need to have a 1 way valve in the booster vac line so the booster can hold vac pressure. Don't worry about what cam you have. It won't make a big difference. Basically every booster assisted brake system has a one way valve. Go down to the local wreckers grab one that fits the hose id you are using and install the sucker. There will be an arrow install the valve pointing to the manifold. If you do have a valve already installed it may be faulty or the booster diaphragm maybe stuffed and a rebuild will be needed.

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1928 Model A CC Pickup

your brake calipers and wheel cylinders may need to be recond/replaced. They sieze up over time...

If you start the car with your foot on the pedal (after leaving the car to sit overnight) does the pedal go down any further once the engine starts? (you might need to pump the pedal a few times to bleed out any vacuum from the booster before trying this) If there is no difference with the pedal feel with the engine running or stopped, then it certainly sounds like your booster.

Even with a reasonable cam in the engine you should still get assistance from your booster. Regardless of cam you will pull a vacuum with the throttle shut, especially at higher revs.

I wouldn't think this is a cylinder / caliper problem. If they were that rusted up, then the brakes would tend to stay applied once you did manage to apply them.

The booster might need a rebuild (assuming all other components - push rods etc - are correctly installed and adjusted)

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They have drifting in forests now?
What will they think of next?

hey warps, thsanks for the heads up mate, i just tried the foot on pedal thing then started it, no difference at all, so ill put another booster on and see how it goes. thanks

I'd start with the basics first. If the car has been sitting for a few years, I'd change the fluid before I did anything else, as this will need doing anyway. Also check to see if the pads/lining has been contaminated.