Manual Brakes

[PatTroy]

Anybody have a successful manual brake setup? I'm travelling down the rabbit hole...

[nelsonj]

Yes, always put the car in 2nd gear when you park.

[carl]

I'm not sure what you mean by successful but I assume you mean the car will actually not move if the emergency brake is fully applied. The Fiat emergency brakes are marginal at best but if everything is working correctly it should be difficult to move the car if sitting on level ground. Shouldn't be all that hard to accomplish if the brake system is in good shape such as good quality brake pads, polished and lubed brake caliper wedges, clean rotors good emergency brake cable and cable adjusted to factory specs. Most spiders get little use over the "driving season" and a lot of the issues I just listed are not to spec. Jack up the rear of the car and see if you can turn the rear wheels in neutral with the emergency brake on. If you can then something (or a lot of somethings) are not to spec.

Oh yea, make sure you leave the car in gear when parked as noted.

[baltobernie]

Are you looking for information about switching from vacuum-assisted brakes to non-assisted?

[PatTroy]

Yes, Baltobernie, I'm talking about non-power-assisted brakes.

There are a couple of parts of the equation which are not easy to quantify (i.e. retraction distance) that can have a big effect on pedal travel/feel. Just wondering if anyone has a car with an acceptable non-assisted setup who would care to share their learnings.

[baltobernie]

You can see my setup beginning on page 2 of this post:

http://www.fiatspider.com/f15/viewtopic.php?f=17&t=7936

Were I to do this again, I would have a local machine shop shorten the actuating rod and install a threaded CW/CCW barrel with lock nuts. This would allow a cleaner installation, without a spacer between the firewall and M/C. One could adjust the rod after installation to provide the correct amount of slack. I have a leaking booster I plan on disassembling to salvage the rod. (I also have some steering dampers to be machined to accept new seals. We'll see if Winter ends, and driving season begins, before these projects get completed )

You might also investigate other M/C's, as suggested in the referenced post above. Wilwood, for example, makes a compact (albeit single- reservoir) M/C that if properly sized, would reduce pedal effort. Please let us know how your project progresses.

[PatTroy]

Awesome info thanks!

If I'm following correctly, this just removes the booster and re-uses a stock MC with a prop valve correct? Did you also maintain the stock calipers? Does anyone know the stock MC diameter? 3/4" I think?

I will be set up with dual MCs and a balance bar, but I'm not sure if I want to change the calipers. That's what I'm hoping to ballpark by understanding the setups of others.

[baltobernie]

If I'm following correctly, this just removes the booster and re-uses a stock MC with a prop valve correct? Did you also maintain the stock calipers?

Yes.

[carl]

The X1/9 uses the same brakes as the spider but without a booster. The MC is different since it sits under the dash but I don't know if the internal specs are the same.

The 128s came with and without a booster, they used the same MC as the 124 and the same front brakes but with rear drum brakes. I converted a few 128s to rear discs from a spider with no problem.

[PatTroy]

Thanks for the input Carl.

Anybody else know what the diameter of the non-boosted cars MC was?

One of my design criteria is to have the MCs in the engine bay. Brake fluid inside the passenger compartment (while many do it) is asking for trouble in my opinion. It also helps to have better access when you bleed brakes ~6 times/year.

[carl]

Anyone who has worked with the MCs on an X will agree with you wholeheartedly, what a royal pain in the ass to deal with those things.