I have a 93 civic hb that needed the front brake pads replaced, so I replaced the pads, bled the brakes, and topped off the fluid. at no time during bleeding did the fluid get below the min line in the resivoir. after the bleed while I am driving I notice that while stopped the pedal slowly goes to the floor, like the bleed port is slightly open. but I could let off the brakes and step again and they grab whith the pedal all the way out, but it slowly goes to the floor again. I checked the resivoir and it's still full so I don't have a fluid leak, but I think it may be a vacum leak. I looked at the vacum hose going to the booster and it looks good. is there a check valve that may be going bad? or is it the valves in the master cylinder? if any has had this happen and knows what it is please lmk.

thanks

 

my integra did that i could never figure out what it was

 

I wouldn't mind so much but when it gets to the floor a few seconds later it starts to roll so I have to use my e-brake or pump the brakes once.

 

are you sure there is no air in the caliper/lines?...and the res. cap is all the way on and tight?..done it once, left it open and not tight enough and it did that, and once a little air in the lines and same exact thing.

 

master cylinder.

 

I put the cap on twice, and we made sure there is no air, I will try the cap again but I am leaning towards the master cylinder myself, I may just swap it anyway since I want to upgrade to rear disc. any chance it is the booster?

 

turn the car off pump the pedal if it builds pressure the booster is good. Turn the car on and it should go back to a softer pedal depending on how bad your master cylinder is. Thats one way to test your booster.

 

if that's the case the booster is good, cause it'll get hard to press, but with the car on it depletes. I guess I need to get a new master. I currently have rear drums but plan on upgrading to disc, so should I go ahead and get the master that is for the si since it'll be valved for the rear disc, or is the cost of a master cheap enough that it doesn't matter? thanks

 

def master cylinder the longer you wait the worse it will get

 

Master cylinder.
The m/c is not what is valved per say for the rear discs its the proportioning valve on the firewall. Get a m/c from a 4dr EX it is the largest bore out there for more capacity 15/16" or 1" bore.

Frank
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