[Stevew]

If I maintained a proper log book, as I’m sure all conscientious Alfisti do, I’d be able to tell for sure the last time brake pads on the left rear wore through and scratched up the rotor. I’m thinking about two-three years, and since I don’t put many miles on the car, not more than 3,000 miles. I was able to turn the rotor, replace the pads of course and all was well. Interestingly, that was the first time I even had an issue with the rears in 17 years (!).

It just happened again and a new rotor and pads are en route. Upon disassembly, nothing out of the ordinary, other than an oily residue of pad material, rotor debris and, I’m guessing brake fluid on the caliper and splash shield. Pistons retracted with a modest amount of persuasion from my channel locks and seals appear sound, although that fluid has to come from the system. Inspection of the right side, which got new pads last go around, revealed lots of meat and nothing out of the ordinary.

One additional observation, the outer pad wreaked all the damage, although the inner was getting close to contact as well. The outer was not uniformly worn, with the trailing edge contacting first.

Speculation on why the left rear is eating pads welcome.

 

[Stevew]

 

[Alfajay]

One additional observation, the outer pad wreaked all the damage ....Pistons retracted with a modest amount of persuasion from my channel locks .....Speculation on why the left rear is eating pads welcome.

I'd say that your LR caliper needs rebuilding. Although the pistons retracted with a modest amount of persuasion from your channel locks, keep in mind that nothing pushes them back normally. The pistons have to be loose enough in their seals to withdraw as hydraulic pressure is reduced. The outer piston on your LR caliper is too stiff to retract, probably due to corrosion or dried-out brake fluid on the piston surface.

Now if both rear calipers were dragging, I'd also suggest an internally swollen rear flexible brake hose as a possible cause. And if it were me, if I was rebuilding the LR caliper, I'd do the RR one at the same time and replace the hose too while I had the hydraulic system "cracked".

 

[6alfas]

Yes, your caliper is sticking and needs to be rebuilt or replaced. Rock Auto has remanufactured calipers for about $50 each. If you don't know when your flex hoses were replaced, this would be a good time to do that as well since you have to bleed the system.

 

[spiderserie4]

photo of the rotor? that must be pretty scored too...

 

[goats]

the 'oil' could be diff lube leaking out of worn rear axle seals, rather than brake fluid. As long as you are going to do brakes, as a matter of course, I normally change the rear axle seals as well.

 

[Stevew]

Well, I bought an inexpensive caliper rebuild kit that was purported to fit my caliper (ATE) but the bits were too big (550cm vs 400cm +/-) . Product was by Centric, 143.9002. Only $10 so no financial tragedy.

BTW, Rock Auto calipers suggested above are out of stock.

Other options are north of $150 for a complete caliper and I’m not eager to go that high.

Google search continues and if if I risk another kit, I’ll check seal diameters with the seller first.

Centerline...duh.

$36 for kit plus caliper internal seals. Here in three days.

 

[spiderserie4]

this seems to state that the 143.90002 is for the fronts

and that 143.90009 is for the rears
need a cross ref. for rebuild kit for rear caliper

 

[PSk]

Only 3000 miles since rear pads replaced, wow!

I'm amazed your car moved. Be careful driving after the caliper rebuild, she may accelerate like a F1 car released from a safety car period

Pete