left front brake pad dragging after caliper failure

[pianoporsche]

So I lost my left front caliper on my '98 Porsche 986 Boxster.

The two caliper bolts completely came undone (I suspect lack of blue thread lock used when rotors were changed about 3 years ago).

The caliper rotated forward and the hard line from the caliper to the soft line was completely sheared off.

I was able to pull over and avoid an accident.

I reattached the caliper, replaced the hard line and re-bled the system.

I did notice that the ABS(?) line was damaged, See pic:



The pedal is now firm but the front pad is dragging. After a short ride the rotor is hot and you can hear and feel the pad dragging.

The damaged electrical ABS (?) line extends from the caliper up into the wheel well into the master cylinder area where it joins what appears to be the main wiring harness. It does not seem to have a connector before extending up into the wheel well.

Is this part replaceable? Do you think this is contributing to the stuck pad? Should I replace the caliper and pad?

Any advice is appreciated.

[78F350]

That broken connector is for the wheel speed sensor and the break wear indicator. The speed sensors are vital for the ABS. I know that Pelican Parts has sold that connector with a couple feet of wire to either put connectors on or splice into your harness.
Just found it: https://www.pelicanparts.com/More_Info/99661296500.htm?pn=996-612-965-00-OEM

[pianoporsche]

Thank you 78F350!

If the wires were compromised, would that affect the pad from moving properly?

I suppose the caliper could be damaged from the jolt of being jammed against the rotor

[Burg Boxster]

BOTH caliper bolts came completely undone? Very very odd and def not due to lack of blue Loctite/threadlocker. Shear failure is way more common on those bolts (especially during removal - not fun). How long had it been since you or any qualified mechanic last inspected them/the area?

Sure, many say it is overkill, but now you better understand why Porsche calls to replace caliper carrier bolts (stretch bolts) each time. People often think/feel knowing/having [even] 100% vehicle history grants calculated leeway to forego replacement. Is the juice really worth the squeeze though? Especially in your case w a 25 year old vehicle with who knows how many previous brake removals may have been completed on these bolts... Were I to ever re-use bolts... anti-seize would be preferable to thread locker anyhow due to heat and dissimilar metals. Simply, replacement is very cheap insurance.


Anyhow, at minimum you need to rebuild (or buy a rebuilt) caliper for that corner as:

(a) you had a failure for unknown reasons (why caliper bolts went awol)

(b) caliper is def now hanging up w pad dragging

Causation = correlation? Maybe?

Again, cheap insurance on 50% of the two vital components (tires being other) keeping you safe on the road.

Good luck

[78F350]

It should not cause the binding, but will cause the ABS to fail. I expect that the caliper is damaged/jammed.