89 Prelude brake issue

[PlanetDude]

89 Prelude SI, 2.0, 5-speed, red.... 4 wheel disc brakes...

Brake line let go under rear seat on passenger side, had a shop replace it. Ever since, have had a soft brake pedal when the car is running.... Took it back to the shop and they re-bled it, said they didn`t get much more air out, and said I could have a master cylinder issue. Is there a simple way to narrow this down a bit? Haynes manual lists proportioning valve, power booster, master cylinder... I don`t want to start throwing parts until I have a better idea.

Brake pressure was fine before line broke, although did have a touch more travel under hard braking conditions.

If anyone has any background on these, I`d appreciate it..... only owned the car since October, so not 100% knowledgable with all repairs.

Thanks

[BullShifter]

It's probably the master. If the peddle went to the floor when the brake line broke the seal on the master could have been disturbed. Usually only an older car issue.

[PlanetDude]

Thanks dude.... I wondered what might have caused all this.... have a new master on order, so I`ll get it swapped out.... any advice for swapping a master? Anything I need to know?

[BullShifter]

I can't go into detail because I have not* worked on an '89 Prelude but I'm sure it's just like every other car.

Make sure to bleed the new master before installing "bench bleed"
Suck out old fluid from old master
Loosen brake lines
Remove nuts
Remove line
Reverse for install
Start the lines before tightening the master to the booster
If it were me since you had an issue already, I would bleed the whole car again

[PlanetDude]

Whole car has been bled twice, with little change. I`m thinking it`s either air in the master, or something faulty inside.... new master is quite cheap, so I`m thinking if I have to remove the old one to bench bleed, it`s just as easy to install a new one.

Besides, I imagine it is original, and at 21 years it`s probably not a bad idea to just put in a new one.