You have to bleed both ports on the master cylinder to bleed it properly.

 

A few things...

When you adjusted the MC/booster rod, did you make sure you were rotating the rounded tip separately from the threaded part? It will just spin if youtry and turn it. The clearancein there is supposed to be .01-.02 in, so a few turn with no effect seems impossible.

Don't underestimate pedal free play. There are three points there: the free play, then where the valve in the booster begins to open, then where the valve is fully open. Check this slowly with two fingers pressing the pedal and you should feel what I'm talking about.

Finally, you can reverse bleed the master by putting worn pads or wood or something in the calipers and pumping them until all the pistons are extended. Then press them all back in. Not as effective as a Phoenix reverse bleeder, but free.

 

I extended the rod a lot yesterday. It is now officially 1/4 inch longer than originally. Well just a hair short of a 1/4". I used a measuring tape and all.

The pedal felt better while car was off. Once started I could nearly bottom it out. And when I drive it.. the pedal definitely bottomed out and with weak braking. The braking power increased a hair after this yesterdays rod extension.

I went to the junk yard to look for booster/mc combos. I did find a 929 but had crappy takes pressure. So I eft as is. Could you believe half of the cars on the junk hard still have nice firm pedals that feel 100 times better than mine... .....
Anyways. I should have a s5 tii booster and master pair coming in a week or so.


Also. I was re reading clokkers threads on mc upgrades and realized one of the times he couldnt get the brakes to feel right so he took it somewhere to get "power bled".

Who here thinks power bleeding might fix my issue?

 

lmao! yes. i've had stuff like that happen a lot, the j/y car is nicer than mine... i've had a bunch of FC's and some have mushy brakes and some don't, and i haven't been able to figure out why.

the best results were from my 87 GXL, i bled it the normal way and it was ok, but it got better after i bled it backwards. apparently once you bleed the rear the pedal can be too hard to bleed the front, so it helps to bleed the front first.

the car i've had the most mirrors yours is a 91 coupe, i put some rebuilt FD calipers on the front, with a new master and we bled it ALL DAY. the first push of the pedal felt great, but the second push of the pedal and it was mushy again.

it really sounds like there is either air in the system still, or you got a bad rebuild on the master.

 

i just quite simply think you have been having bad luck with the reman masters.

they ream the **** out of the bores and don't check tolerances, with cheap hardware it's easy to have a brand new master that is bypassing internally.

 

Well today I went to junk yard looking for upgrades and found me a Subaru legacy master and dual diaphragm booster and also got me an extra brake proportioning valve out of an s5 vert. The brakes on the Subaru were nice and solid. I'm so tempted to try it. I'm missing a splitter, forgot to grab it of the fc:/

 

My brakes are the same way now. They were perfect, and then I changed them and pressure bled them and now they feel like ****. So frustrating

 

Pressure bleed?

 

That's what my buddy called it... Pretty much a special cap with a hose fitting that goes on to the ms and then there is a big jug filled with brake fluid that is pressurized and attaches to the nozzle on the cap and then you just loosen the bleeder valves one by one .

 

I need me one of those. My budd said he had something like that, I should ask him for it.

 

using the factory service manual. There is an adjustment to the pin between the master cylinder and brake booster. The tolerance is 1mm with 18 inches vacuum applied to the booster. This adjustment will make a big difference especially if the mc has been changed.

 

my daily driver's brake pedal is ROCK HARD. A also have braded stainless steel brake lines.

 

bleed the brakes starting with the furthest tire from the MC and work your way forward.

 

my last comment. Turn the rear brake pistons all the way in. Then bleed the brakes. bleed the entire braking system until you get a hard pedal before you even think about pulling the e brake handle.

 

Pressure bleeding:

(It's the same for clutches as it is for brakes)

<iframe width="640" height="360" src="//www.youtube.com/embed/NtOOyN0vVeg?feature=player_detailpage" frameborder="0" allowfullscreen></iframe>

 

I have SS lines too Michael, still feel like ****. I'm just going to re bleed them the old way...

 

OK. I drove my car about 20 miles yesterday. That's the longest she had moved since the rebuilt engine. SHes is now legal! Insured and tagged. WOOT!

although... Things to note.

MY rear pass. brake calipers is dragging and with uneven rotor/pad wear. I could smell the burnt/heated brake pads but everytime I stopped and took a whiff at every wheel I couldn't really pin point it till I got to a friends shop and I could clearly see the RR rotor rust from sitting had got only halfway removed. Meaning the upper half of the pad is making contact. Where the rotor should have been all shiny from fresh pad contact... it was only half shiny. Its not making full contact so now I suspect this caliper is partially ceased.

Also... I used to drift.. My ebrake is tightly adjusted and doesn't need to be pulled far at all to engage. Should I unhook the ebrake cables before I bleed? I was kind of assuming the ebrake is keeping some tension on that rear calipers and is possibly not allowing full strokes of the piston making it hard to bleed?

 

Well this is my legacy master and booster swap. Still working on it. Splitter out of a Camry.

Ill let you guys know by end of weekend if this solves my issues. IF it does fix it. it would mean the master was bad and or the rod adjustment was out.

 

Well folks.... the Subaru master fixed it. My 7 has never had brakes that felt this good. Pedal feel and control is perfect.

After installing the booster and bench bleeding the master, I bled the front brakes good first then I did the correct mazda order. It took that one time ot bleed the brakes an they feel great.

I have noticed the front driver wheel locks up before the passenger front.

Possibilities. for ^^

1. not bled well enough and might have bubbles in the pass front brake line?
2. I had re made the front driver brake line and I did not coil it like the original was, I just made it a straight shot.

 

Do I get to say "I told you so!" yet?
Why yes, yes I do.


Your new brake hardline has nothing to do with it.
The disparity may be air bubbles, you should rebleed the lines after a few days anyway.
It may just take a little longer for the one side to bed the pads and the feel may even out after a short time.

I'd wait a bit before getting too worried.

 

Length of line makes no difference according to Pascals Law.
The correct procedure for bleeding is start from the farthest point from the master. So RR, LR, RF then LF.

 

Given that the front and rear circuits are completely isolated from each other, I don't see why this would be true.

 

Yes. You rightfully get an " I told you so" :p
All your trial and errors have helped me a ton with this clokker.

Also after I bleed the fronts I then went and did the correct order or bleeding. So no worries on that. I will re bleed in a few days.

 

Well I dont know about RX7s being diagonal split or front and rear split. But on a diagonal split setup that is the correct procedure. I do it the same way on every car anyway.

 

Rx7 is just front and rear.