my brakes have been rebuilt, caliper, pads, drum, shoes,, wheel cylinders, master cylinder. pretty much the works. When i mash the brakes i dont get anything, but if i pump it once and then mash them it works like a new car. what could the problem be, i have bleed and rebleed the system just not sure what is going on here, could it be in the vaccum boost ?? not sure what is going on help? thanks

 

Are you sure the brakes are bled properly. To me it sounds like that is still your problem.

Get someone to pump the brakes up, and open the bleeder starting from the caliper furtherst from the master cylinder. Then after the pedal goes to the floor, you tighten the bleeder back up. Once again you get the assistant to pump the brakes several times and do it until all the air bubbles come out.

To me this sounds like its still your problem, start simple and go from there.

 

Yea, it sounds like air in the lines,,,can be hard to get them right sometimes.

Rich

 

well if i have some one in the car hit the brakes and i loosen the bleeder nothing but fliud at every one, and at the master cyclinder. am i missing somthing?

 

Rear adjusters set properly? Having those backed off all the way will also cause the pedal to need an extra pump.
Pull the drums, and adjust them out till the drums touch both shoes lightly, then try again.

 

If you let the fluid tank get empty even if for only a second, you could have a bubble way up the line and itl take alot of bleeding to get rid of it. If nothing else, bleed each one alot. Also check for wore/rotted lines. If they are to shitty theyll expand causing ur loss in pressure

 

As big jim stated and others, air is still in the line. It's hard enought to bleed the system when youare just changing fluid let alone a complete overhaul. It's usually suggested that the master cylinder be bench bleed before it is hooked up to the system and as Jim stated if that reservoir went below a certain level then there is air in there and it will either take alot of rebleeding or have to take it into someone and have it power bleed.

 

I'm with the Doctor and Big Jim on this.I replaced my rear Calipers..easy Job Right?..nope..took Three trys to get from the Lines.The thing that I noticed when there was air was it would be fine,Until you got going then you would have to Pump the brakes to get a good pedal.I'm no Novice when it came to doin brakes.I knew what the Problem was.The Only thing I can give you as a Suggestion is to never let your Master run out of fluid when doin the Job,Or you are starting over From Square one.and Yes that might entail priming the Master again to get the air out of there too...also RX7doctor (I'm pretty sure) had a write up on proper bleeding Of brakes when you have to do the whole system.If not (sorry doc,if I'm mistaken) you can do a quick search on Bleedin brakes using the Forum search tools.

 

After replacing my brake calipers, master cylinder, and brake booster I had to spend hours and hours trying to get all the air out of the lines. Its a very repetative job, but it needs to be done. I am with everyone else on this one. You got to make sure all of the air is out of those lines.

 

well thats a plan then iw ill be bleeding brakes today, thanks for all the insight, i guess its got to be brake lines with air in them, sounds exactly like my problem. thanks