This is the wierdest problem I've seen, I just bought a 91 lx, the sister to my 90 ex... anyways, When I downshift normaly the brakes become extremely spungy, to the point where its on the floor, then when I downshift while double clutching its perfectly fine. My friend was telling me I should bleed the brakes. I was looking through the book and it said it could be the brake booster... any ideas?

 

Check for seepage around brake master cyl. and if necessary replace it.
Double clutching was used on old school muscle cars, not necessary on our hondas.Due to synchros in tranny
Brake boosters rarely go bad, but who knows....test it

 

If the brake vacuum booster goes bad the brakes will get has hard as a rock and itll be difficult to stop the car.

My vacuum booster went bad on my 93, and it was a bitch and a half to get in and out. Finding all the bolts is easy, just getting the damn thing situated right in the small corner of the engine compartment almost killed me. It took 2 people 30 minutes just to get the damn thing out, and we were sweating to death in 100 degree heat last summer when we did it. putting it back in the corner is no easy task either.

Lets hope, for your sanity's sake, that its not the vacuum boost thats going bad.

 

The brakes arent as hard as a rock, and its not hard to brake. Its just I dont get any real braking power until the pedal is almost to the floor. I think it still might be the booster though, but as you've told me, and as I've read, its a hard thing to get to. I'm going to wait till the end of the week to have a mechanic look at it, any other ideas until then?