# B5 front caliper piston over-extended??



## sudrabs3 (Sep 4, 2006)

1998 1.8t Passat sedan FWD

Did my front brakes pads and rotors yesterday. Did something kind of stupid while multitasking. I had reinstalled the left caliper with a new rotor and pads and pumped the brake to seat the pads on the rotor. Unfortunately I also had the right caliper off the rotor and pads out, so when I pumped the brake the right piston extended quite a bit. It didn't feel like it came out completely, but when I started pushing it back in with that that "special tool" (metal plate and a screw with a small washer at the end), it kind of jammed since the pressure on the piston was only on an edge. I could see that it was going in crooked. I stopped and then gently and briefly pushed the brake with my foot again to slightly extend the piston. I then put the old brake pad in the piston. It looked straight and then used the tool to push it back in. It went smoothly and retracted all the way in.

Now, my questions:
1) Is it possible that the piston came out totally, or too far, or is there some kind of seal/stop that prevents that?
2) Since it started going back crooked and kind of jammed, did I damage it? It did go in smoothly eventually when I straightened it out.

Thanks,
Nick


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## IJM (Jul 30, 2001)

sudrabs3 said:


> Now, my questions:
> 1) Is it possible that the piston came out totally, or too far, or is there some kind of seal/stop that prevents that?


There is a gasket the seals the piston inside the bore, but if you overextend the piston it can pop right out. I don't think you got it quite that far, but probably far enough so it got jammed up a bit. 




sudrabs3 said:


> 2) Since it started going back crooked and kind of jammed, did I damage it? It did go in smoothly eventually when I straightened it out.


It's probably fine. I've had them jam before when I've rebuilt calipers, and unless you're forcing it in there with a vice or something, it's hard to damage it.


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