Rear brake caliper adjustment screw, came out, what to do?

[bob850]

I was trying to retract the piston on the rear brake caliper to replace the pads, and the adjustment splined screw just came out. When I try to put it back in it just spins freely, it is not engaging anything, also brake fluid started dripping out. I have pushed the brake pedal down with a 2x4 to prevent the master cylinder from going dry. Does anyone know what I need to do to get that splined adjustment screw to reengage? I’ve fiddled with it and fiddled with it but nothing seems to work.
The splined screw was retracting the piston for a while, but it didn’t go far enough and then when I took my Allen wrench out the splined screw just came out with it. Any help would be appreciated.

 

[TheMAN]

sounds like you're going to have to take it apart to put it back together.. the shop manual has those details, but seeing as what happened, I bet you some parts are worn/seized/rusted... just replace the caliper

meanwhile, you can get something to pinch off the brake hose so it won't leak as bad

 

[Minds_Eye]

Is the spline screw stripped? If so, you could borrow the adjustment spline screw from the other side to complete the job. If not, it might be something is stripped on the internal side of the mechanism.

Regarding the leaking, it should have been underneath a cover bolt with a copper washer already, so just put that back on to stop the fluid dripping out.

Check this thread: Rear Caliper Adjustment Screw Allen Key Size?
you might be able to adjust the internal mechanism by pumping the parking brake like a thousand times. I was just battling this today and could not get the pumping method to work.

 

[bob850]

The spline screw is not stripped as far as I can tell. When I put the screw into the hole it’s like it’s not even engaging any correspond piece. It’s just in there spinning freely. I’m not sure what’s going on. I read about turning the piston with pliers, I guess I’ll try that. Otherwise I’ll just replace the caliper unless I get a better suggestion.

 

[bob850]

So I rotated the piston with pliers and it goes in and out when I rotate it. But again, I can’t get the spline/allen screw to engage anything. When I look inside the hole, I do see a little cut out area, where I would expect some corresponding spline teeth to be, but I do not see any. Perhaps something has moved internally? Also, fluid leaks out that hole, so whatever seal that normally prevents fluid from leaking out that hole is apparently not doing its job anymore.

 

[Minds_Eye]

Do you have the screw labeled 1 here in place? If that's in place then it shouldn't be leaking out. It has a copper washer on it.

Are you able to push the piston far enough back in to put the pads on and fit it over the rotor? If you're able to reassemble and bleed everything, and verify the brake works, you should be good to go even without the adjustment screw working properly.

 

[bob850]

If I put the “cover“ screw with copper washer back on, the fluid does not leak out. I was under the impression that the fluid should not leak out even if that screw is not in place, am I wrong on that? I purchased a rebuilt caliber from Napa today, but have not had time to mess around with it yet.

 

[Minds_Eye]

No, it might leak out if the screw is not in place.