(T) Adjusting rear calipers, how to.

1978 Spider
Rebuilt the rear calipers and have not received my workshop manual (CD).

What is the procedure for adjusting the rear calipers??

Before refitting the rear brake calipers make sure that the scored line on the part of the piston that presses on the brake pad is uppermost, this line is above the central groove that fits over the brake pad backing plate pin?. otherwise the calipers won't bleed properly.

Also support the rear axle not the chassis on jackstands otherwise the rear brake compensator valve won't allow fluid to reach the rear brakes.

Don't adjust the handbrake cable yet, I'm assuming you slackened it in order to remove the rear calipers for overhaul. You'll need to be able to get a full movement of the parking brake operating arms on the brake calipers.

Bleed the brakes, starting at the one farthest from the master cylinder and work towards and ending with the one nearest to the master cylinder. You may have to repeat the operation a couple of times. Be careful the fluid reservoir is kept topped-up, iirc it's quite small, there may be two of them side-by-side. You should now have a firm pedal but excessive travel.

Operate the parking brake lever a number of time while pressing the brake pedal. I can't remember if you do this at the same time, or alternately, or if you hold down the footbrake while operating the parking brake lever. When you think there no more reduction in brake pedal travel to be achieved, adjust the parking brake cable under the car at the cable stirrup. Don't set it too tight. Iirc I used to apply the lever by about 6? clicks, nip underneath and adjust the cable adjuster fairly tight., this was a quick way of adjusting it, when working on my own, so that it was fully applied at about 6 clicks. Make sure neither wheel is binding when released and that the cable moves freely and operates both caliper parking brake levers equally. The cable tend to seize up easily. if you remove it from the car completely, you can work on it to hopefully free it up. If fitting a new cable, take the opportunity to lube it well before installation.

I worked as a mechanic for a Fiat main dealership in the 1970's and this is how we used to set up the 124 Sport Coupes (same braking system on the 124 Spider).

This is about as good as I can remember the procedure, it is almost 40 years ago after all!. I checked a Haynes Shop Manual that I have and there's nothing about setting up the rear calipers. Maybe other members have better info or a different procedure?

Hth,

AL.

Thank you Al, that's exactly what I was looking for. Would have never thought about supporting the rear axle or indexing the scored line in the piston.

You're very welcome, Ken.

AL.

Great news
Indexed the rear caliper pistons properly, jackstands under rear housing and bled brakes... Full pedal and ebrakes work!

Hi Ken,

Well done!

Wasn't so hard was it?

Now, you've just got to sort out the electrics......


Regards,

AL.

Yes, fortunately I have another 78 (only two months older) for a wiring donor. Already bench tested most relays and components.