Brakes suck!
 

I know this is not the brakes forum but no one has any answer in there.

I did an Ls swap into an Lt1 car with a TSP 233/239 cam and used an Ls master cylinder with all Lt1 brakes, I replaced booster, calipers, and a second LS master and I have 17 in of vacuum on scanner from MAP sensor and the peddle is hard but braking power is minimal. ABS is deleted and I have a proportioning valve in the rear. If I pump brakes I can kill car so I think it might be a vacuum problem but I really I don't know b/c I threw all these parts at it and it still has shitty brakes.

Please help!

Let's try GM+R.....

Can you define "suck?" Are we talking the car stops 20 feet too long? The things you are looking at would be in play if you had a very serious problem.

If you are just braking longer than you should, I'd look at the slider pins on the front brakes and that proportioning valve first.

I have to break early to be safe and you could be going 20 mph and stand on the pedal and it just rolls to a stop and the pedal is rock hard, its not safe at all.

???????????

Look at the slider pins on the front brakes and make sure they aren't bound up. I'd also take that proportioning valve out of the equation and see what happens. It sounds like you aren't getting any bite in the front brakes.


Do you have an infrared thermometer? If so, you might be able to get some temperatures off the front/rear rotors and confirm.