long pedal after sport-brake swap
 

I put sport calipers up front and now I have a long pedal.

Specs:
1991 car and master
big sport brakes up front
standard 1.8 rear
wilwood valve

pedal drops 1 inch then gets firm on the brakes
bled the brakes all the way around, multiple times
bench bled the master


confused Time for a tilton pedal box?

you has leak. abs?

does the sport package have the same brake cylinder as regular?

I'm pretty sure I don't have a leak. No ABS. I have budget brake fluid in it because I'd rather use that to fix bleeding issues. I doubt that is the problem because the pedal is still firm after it drops. It feels like I have a really big air bubble (had this problem once before).

Targa Miata

negative. I can handle more pedal movement, but not the 1" dead zone. I've read that the 1" drop is an air bubble issue, not master cylinder displacement issue.

Hustler,get a power bleeder,it will makes things alot easier to bleed air out of the braking system.

It sounds like you have a big air bubble trapped somewhere.

I agree spike, most likely in some of the funky fittings or wilwood valve. I've had this before where it seems like I have to drive the car for a while, then the air bubbles migrate to the bleeders...is that crazy?

Can anyone confirm this symptom to NOT indicate inadequate master cylinder displacement?

this happened when i would bleed my ABS equipped miata. Air pockets would get stuck in the ABS unit, I would have to cycle the unit a few times before i could bleed to force the air out.

I think the turbo is thugging the brake parts. I'll ask it nicely to stop.

On a side note, anyone have a link to good, affordable heat shielding for the brake lines and something to wrap around the valve?

You can head down to BEGi and ask them to make you a custom heat shield.

or search. since it's been covered in multiple threads.

"heat sleeve" was the magic I needed. buy buy buy

If you had the master off, it could not be adjusted properly to the pedal. IE-pedal "falls" till it takes up the slack and makes contact with the master, then it's brakes like normal.

Or you still have air in the master, which is my second guess. I doubt you bench bleed it well enough. +11113232 to a hand-held vac pump, as these make bleeding shit a lot easier. (read-you'll never do it without one after you try it)

Also since you changed calipers, they could still have air in them. You should gravity bleed those too.

I had this 1 inch slop before with the stock brakes, and the same one inch slop with the sport brakes.

Its like 1 inch of nothing, then firm pedal. From what I remember it was the same with another MT netters car, so I just learned to live with it. Braking performance has always been very predictable and consistent.

Maybe I should lengthen the master cylinder piston and see what happens with the slop.

I thought that was only possible with the clutch master?

pop the master off (two bolts and a tug-job) then take the black rod sticking out the back and spin it. Then you have a longer or shorter engagement height.

Hustler,I suggest you get one of these,once you use one,you will never bleed brakes without one again.

Motive Products

I have the miata specific bleeder.

I have one for my vw, just need a miata-compatible cap.