still soft brakes

[narfire]

Well the car does stop but still not happy with the "brake feel" To date I've changed all calipers to new re-builds from Ital motors. I've put a third MC in and get fluid at the three holes. replaced all steel lines and soft lines.
I have bled the system stupid or perhaps I'm stupid.(note to self...frustration) Jacked the back end up,lowered the front end,tapped the MC & got air from the rear driver. solid stream now and all corners.Used pressure bleeder.
If air is getting into the system, would there be "wet" at any point where air is getting in?(can't notice any at conections/lines)
I think the next thing is to by-pass the compensator even though it looks dry.
Currently I have about an inch /inch and a half of pedal travel before some brake is felt then another inch or more before the car slows down noticably and firewalled they do not lock up.
Pumping the brakes does not seem to build up resistance/firmness?
It's been 30 years since I last drove a spider but I do pay more attention to traffic and distance with the spider than my 92 VW and it has rear drums.
Short of throwing out a danforth to stop,any ideas out there?

[racydave]

It would be hard to think you still have air in the lines after all that! I like to open the farthest bleeder, and let it gravity bleed for a hour or more. Then open the next farthest bleeder... Then with help, bleed with pedal power. Is your booster working? Plug the hose and try it out. Also if you could dis connect the arm to the rear valve where you know there is fluid at the rear bleeders, and test drive that? I used my flairing tool and ran the rear line to the Tee on the axle, and tossed the valve.

[kilrwail]

I think you and I have the same symptoms, although my pedal is firmer than that. Going back to one of Alvon's older posts, I think the only cure for mine would be to remove the m/c and bench bleed it, while rotating it in various directions. I believe the bubble to be forward of the rear outlet, so I would have to hold the m/c vertical with its nose down for that bubble to rise far enough to escape. Maybe when the snow comes I'll try it, but for now I'm drivin'

[pope]

Drop a Viagra in each brake fluid reservoir. That should give you a firm feel.

[mdrburchette]

But I'd be concerned if it lasts more than 4 hours.

[narfire]

Thats ok, 4 hours gets me to Vancouver.Perhaps I should talk to my doctor friend and see if I can get a bucket of those things,don't think he'll believe me when I tell him it's for the fiat,

Think I'll pop the MC off and tip it/whack it/and make it bleed I think it's the backs that are the problem,there is no air in the fronts. The left rear seems to have some bubbles come out when I pressure bleed. Think I'll have to make the missus a dinner if she'll help with the pedal work.
You'r right Peter,nows the time for driving,weather, other than right now,is top down time.(calling for snow in the passes) and yesterday was 28 deg cel (81 F).

[ga.spyder]

Narfire,I just bought a pressure bleeder.How much pressure did you use when you bled your brakes?
thnks,Craig

[narfire]

I used between 5 and 10 pounds. The main problem I have with the thing is getting a good seal with the cap. If not then make sure you have a ton of rags tucked inaround the res. as fluid will be every where. After a while I thought I got smart and made sure the res. was full and the bleeder was empty. This pressurized the system without it oozing out of the cap.
Check to make sure after a brake or two there is still juice in the res. Break the pressure at the bleeder and re-fill the res.
Of course all this dicking around is avoided if you have a good seal at the cap.
I had a cap I rigged from a parts car res. as the universal or the cap that came with the bleeder did not fit the fiat res.
Have fun and have a guiness
Chris

[ga.spyder]

Thanks,Chris
I bought one of the 'Motive Power Bleeder' units with the European res. cap.It seems to fit exactly,but I havent pressurized it with fluid in the tank.I will check for leaks first,and only pressurize to 10 psi.The F1 race is over,and I have some time between church and the Indy 500,so I am off to the garage !!
Craig

[ga.spyder]

In our history on this planet,certain accomplishments stand out.Fire,speech,the wheel,electricity,College football(Go Gators),fuel injection,sattelite tv,and....The Motive Power Bleeder!!! Once the wheels were off it took 10 min. to get all the air out.Firm pedal,no pull.My only reget is that I didnt invent the power bleeder or buy one 20 years ago.Finished just in time for the green flag at Indy.
Craig

[tglancy]

I have also gone through the process of replacing brakes and bleeding them. I did talk to an expert that had the following advice:

They let gravity do the bleeding.

There is the posibility of air inside the rear pistons as they are hollow. The scribe mark must UP (main grove in center, horizontal and smaller above it) A good practise is to fill the rear brakes before installing and move it around to get the air out first.

If correct there should be a little over 1 inch of travel when the vacuum assist is empty. (car not running pump until empty)

It may take two or three pumps to get to that 1 or 1 1/2 inchs.

When driving with new / rebuild calipers they tend to drift back a little so the first time will be a little long. The second pump should be higher but the vacuum assit will make it feel longer.

[narfire]

Well I should say I'm happy with the brakes now.
Several weeks ago I had the missus help,and bled all the calipers again. Definate improvement but not real happy. I popped the MC off and pulled the plunger in the booster out. Turned the acorn out 1 turn,replaced and put it all back together( note make sure there is a rag over the shock struts as the 13mm nut loves gravity and shock struts) way better but...
Repeated,getting quicker at this evolution, and turned acorn 1/2 turn out. Real happppppy now. 1/2 inch pedal and firm and stop
I'm thinking some MC products might have different reliefs between the acorn nut and piston in the mc and a bit more trial and error is required to get the brakes dialed in.

[kmead]

Another thing to look at is the adjustment of the rear brakes. Ensuring the emergency brake is properly adjusted will remove much of the motion required to have the pads grip the rotors at the rear. Pumping the brakes several times, pulling the hand brake up 3-4 times and then adjusting the cable will remove the slack in that part of the system.

Every little bit helps in getting to good pedal feel.

[narfire]

Thanks for the heads up on the emerg. brake. I'll do that while I'm mucking about changing the spedo cable,which is right after changing the oil out of the trans. and replacing the plastic gas pedal bushings.
Always something.