Brake Booster problem?

[Fiat88]

Now that I've been actually driving my spider, I noticed that I may have a problem with the brake booster. One thing is my brakes are spongy but I have to admit that I didn't bleed them enough after rebuilt the calipers, got new brake hoses, pads, new booster hose. The brake pedal did have a better feel before I did that, so I need to bleed the brakes more. My brake light also goes on and off when driving but the brake fluid level looks to be at the max line.

Also, I notice when I start the car cold in the morning, most of the time if I pump the brake pedal the idle goes down to 500 rpm but levels out to about 800 rpms. If I keep pumping the pedal while the car is running the idle doesn't go lower. Today I pumped the pedal several times to see how the pedal felt but didn't start the car and went inside for about 5-10 minutes. When I came back to start the car to bring my mom to bible study, the car would crank but wouldn't start. It then started after a few seconds but very low idle and the oil pressure light went on but then went out after a few seconds. Brake booster problem, check valve bad? What you guys think is going on? '79 with Auto Trans

[azruss]

spongy brakes means air in the line. get them bled and then see what youve got.

[dmwhiteoak]

Continue taking your mom to bible study and you may think about going with her. It would't do any of us any harm. Bleed your brakes, they will go from spongey to tight pretty quick.

[jsab]

Some years ago I had the same problem with the RPM when I stepped on the brakes. Check your vacuum hose to the booster, sometimes these get a crack or small hole in them, causing a slight vacuum leak. And as the others have said, get the brakes bled.