Rear disc Swap. NEED HELP ASAP!

[92_dr_p]

Well, I finally got my conversion on, after it sitting in the shop for over a year. I bled the lines and went for a drive and had no brakes. Brought it back in the shop and bled it about 5 more times. I started the car with it still on jackstands and the pedal still goes to the floor. I have ZERO leaks and me and the person pumping brakes have bled multiple cars before.

So, now I'm stumped. I replaced the proportioning valve also and was wondering if anybody has had to bleed the master cylinder seperate when doing this. My valve was off for quite awhile so my master cylinder was pretty much completely out of fluid.

Any suggestions are welcome. I've ran a bunch of scenarios through my head and can't think of anything else.

[dannyd]

Well, I finally got my conversion on, after it sitting in the shop for over a year. I bled the lines and went for a drive and had no brakes. Brought it back in the shop and bled it about 5 more times. I started the car with it still on jackstands and the pedal still goes to the floor. I have ZERO leaks and me and the person pumping brakes have bled multiple cars before.

So, now I'm stumped. I replaced the proportioning valve also and was wondering if anybody has had to bleed the master cylinder seperate when doing this. My valve was off for quite awhile so my master cylinder was pretty much completely out of fluid.

Any suggestions are welcome. I've ran a bunch of scenarios through my head and can't think of anything else.

master cylinder took a shit....

[92_dr_p]

master cylinder took a shit....

your sure it just doesn't need to be bled?

[cb007]

try bleeding the MC like you said, you can bleed it wit it on the car. just undo the brake lines and get some clear tubes attached to a female hose fitting that can screw into where the brake lines are supposed to go, then put the open end of the clear tubes in the MC, if it doesn't push brake fluid back in itself then the MC is broken. (if you leave it on the car your gonna have to get someone to look at it while somebody pushes on the brake peddled)

[92_dr_p]

bled the master cylinder with no luck so I replaced it. Still no luck. Any new suggestions?

[baracuda]

bled the master cylinder with no luck so I replaced it. Still no luck. Any new suggestions?

when you say "no" brakes is it that the pedal drops to floor and doesnt stop at all? is it just the backs? or both front and back brakes?

[bruno8747]

You will have a lot of air in the system. Get a vacuum brake bleeder and use that instead of using the pump method.

[Jon]

You will have a lot of air in the system. Get a vacuum brake bleeder and use that instead of using the pump method.

Exactly.

When I did my swap I started to bleed the brakes using the pump method... then quickly remembered I bought MityVac just for this situation. Went around to each nipple, sucked and sucked (wow that just sounds WRONG ) and in about five minutes I was done and had ZERO air in the system and fixed the no brakes feel.

[92_dr_p]

when you say "no" brakes is it that the pedal drops to floor and doesnt stop at all? is it just the backs? or both front and back brakes?

I'll explain what happened the first time i drove it... Basically, the pedal goes aobut 7/8 of the way to the floor and then just barely grabs making me slow down a very little bit. I was only traveling about 10 mph and the brakes did not stop the car.

Exactly.

When I did my swap I started to bleed the brakes using the pump method... then quickly remembered I bought MityVac just for this situation. Went around to each nipple, sucked and sucked (wow that just sounds WRONG ) and in about five minutes I was done and had ZERO air in the system and fixed the no brakes feel.

I guess I could try that. I really don't see how could I have any air left though. I've bled them 12 times now. And the first two or three times I had someone pump the brakes, and hold the pedal as I cracked open a line on the master cyliner. I repeated this with the other line on the MC and then continued to bleed the system.

It's weird to me because the brakes feel stiffish with the car off while pumping it after a bleed. And then when you start it they go almost all the way to the floor.

[92_dr_p]

UPDATE: Read me NOW!!

So, I'm going to list what I've done since my last post in chronological order, than tell you what I think the problem might still be. If I'm wrong tell me what it is, if I'm right than tell me that.

First off, here's my problem. With the car off, I can pump the brakes and they will feel stiff and only go about halfway to the floor. As soon as you start the car you get no feel in the pedal until halfway down and then it goes completely to the floor with almost no feel. Car is on jackstands throughout all of this.

I replaced the master cylinder and vacuum bled all four corners until the master cylinder reservoir was almost to the low line to make sure there was no air bubbles. Still the same problem.

I swapped my propotional valve back to the stock one and vacuum bled again. Same problem.

Exchanged the master cylinder thinking I got a bad one (I bought a new MC, not a used one) and vacuum bled again. Same problem

Now I'm stuck. The rear conversion is off of a 91 SE and my car is a 92 LX. Here is my new theory.........Do I need a DIFFERENT master cylinder? I believe this is the problem because it just feels like the piston size in the MC I have isn't big enough to push the pistons in the rear calipers compared the drum wheel cylinders that used to be there. Please help me.

[fatboy1185]

I doubt you need a larger MC, lots of members keep their stock ones, or buy new stock ones, and they work fine.

[kouzie]

Mine is off a 91 SE too and yet everything work as it should.
Like I said, maybe its your discs set since nothing seem to be the problem .

[92_dr_p]

I doubt you need a larger MC, lots of members keep their stock ones, or buy new stock ones, and they work fine.

So, what do you think it is than?

[johnnyblaze2g]

How did u bleed the brakes? did u use a cup of fluid and an air hose over the bleeder valve..thats the only sure way to bleed them..

[JaK FRoSTWhiTE]

On the contrary, i feel you get a better pedal feel bleeding them manually.

The correct bleeding sequence is...

1.-Driver Rear
2.-Passenger Front
3.-Passenger Rear
4.-Driver Front

And it doesnt matter if its DX , LX, EX or SE.