This is what happened
I picked up an ITR 1" Booster / Master Cylinder, so I sent imy car to my mechanic to install it, nightmare began. He took off the booster and MC from my SI to replace with the ITR. After installed the booster, he realized the MC requires a 10mm fitting and another 12mm fitting. "Assuming Stock is 10mm x 2 for the steel line."

First question. What car did this MC come from. a non ABS? no clue

after swapping the 12mm fitting to one of the steel line, we installed the MC in place. Therefore, one 10mm and a 12mm now. After installation, including bleeding the brakelines and brand new brake fluid. I jumped into the car and test the new braking response, everytime I tried to stop the car. I had to press it all the way to the bottom, Mechanic assuming the MC is no good. explaining some valve in the MC won't close properly which I don't really get it.

Second question. Where can I get a new 1" MC online. Will a part store provide them as well? If I get a new MC. Will the new MC able to bot to the booster directly?

Appreciate.

 

UP

 

anyone?

 

Was the MC bench bled properly?

Just sounds like too much air in the system.

 

The first issue is that the ITR m/c has a larger fitting for the brake hard line that screws into it closest to the firewall - ABS-equipped cars always have one larger line/fitting on them. This requires double flaring your stock line to accept the proper ABS larger fitting, which I'm assuming your mechanic did. This doesn't necessarily have to be part of your problem, but it explains the huge pain in the *** factor for fitting an ITR (ABS) m/c in your non-ABS 99-00 Si.

Secondly if the pedal goes too far down before brakes actuate then a complete bleed from corner to corner, or perhaps even using a nice vacuum pump at all four corners is in order.

If completely bleeding all the sir out of the system doesn't help or fix the issue, then it sounds like the m/c has an internal leak, and you got a bum m/c out of the box.