Hello, the brakes on my 94' del sol vtec have always been bad and not very powerful. Lately they have been getting worse and the pedal slowly drops at stoplights under pressure. Do I need a new master cylinder or a new booster . Thanks

 

A pedal that falls under pressure is a leak, could be internal or external. first if it is external you would notice but if not dripping still need to inspect all the lines and calipers but one thing that can hide from you is the wheel clyinders if you have drum in the rear. but if it is a internal leak you should be able to remove the master cly cap and have someone push on the breaks and depening on how bad it is you will see a gieser coming out of resivour. a bad booster would have a hard pedal and would still hold pressure.

 

First thing to do is start at the master cylinder and work your way all the way through the brake system following the lines to all four brakes checking for leaks. If you find a leek fix it and problem solved. If not most likely its internal and a new master cylinder would be the next step. BTW it could just be air in the lines... have you tried bleeding the brakes?

 

I have bled the brakes and I have disks in the rear. I think that the master cylinder is to blame.

 

bump

 

This happened to me and it was because I put in too much brake fluid.. I took some out and now its fine.