I just picked up a 95 sc400 with 415k miles on it the main issue I'm having is the brakes it feels as if the brake assist is not working I have good pressure from the pedal but I have the stand on it to get the car to eventually stop I'm pretty sure the brake Assist works off of vacum from the engine I'm just not sure where to start I tried holding the brake pedal down while starting the engine and it didn't really move down

 

Sounds like you have a bad brake booster, with that many miles it is time to replace it. It is fairly easy to do 2 bolts under the dash and 2 on the MC.

 

I was afraid that might be the case lol oh well just have to add that onto my list of parts I need I have 2 sc400s one is a 92 the other is this 95 I plan to use the 95 as a DD I want it too look bad *** but first I have to make everything work right the 92 I want to make into a drift car possibly maybe a drag car maybe even a circuit car just have too see what tracks are around me