# Caliper Problem



## VQMatt (Feb 21, 2004)

Has anyone had a problem with the piston in the rear calipers not wanting to screw in? I went to change my brakes today to Raybestos Quiet Stops and all of them went in fine except for the passenger rear. The piston would not screw in, just freewheel. And has anyone had a problem with the CV boots tearing? I just found one of them torn and grease is everywhere.

edit:also, does the check engine light reset itself after a while if there is nothing wrong with the car? I cleaned my throttle body with carb/choke cleaner and it turned my CEL light on.I already reset it, but i was just wondering. Found out my knock sensor's goin too, just great.


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## Jeff (Oct 17, 2002)

VQMatt said:


> Has anyone had a problem with the piston in the rear calipers not wanting to screw in? I went to change my brakes today to Raybestos Quiet Stops and all of them went in fine except for the passenger rear. The piston would not screw in, just freewheel.


What is 'Freewheel'? Also, did you unscrew (not remove) the brake fluid resevoir cap in order for the brake fluid to have 'room' to move back into the system? If you did unscrew the resevoir then you may have to rebuild your rear calipers if they weren't screwing back in. (I am also assuming you were screwing it back in ClockWise, right?)


> And has anyone had a problem with the CV boots tearing? I just found one of them torn and grease is everywhere.


You will need to replace your CV boot but it would be best to just rebuild or replace the whole CV joint (if the boot has been torn awhile then your cv joints are most likely on there way out). Soon enough you will start hearing a 'clicking' sound when turning. Without replacement soon you are on a short path to even more problems.


> edit:also, does the check engine light reset itself after a while if there is nothing wrong with the car? I cleaned my throttle body with car/choke cleaner and it turned my CEL light on.I already reset it, but i was just wondering. Found out my knock sensor's goin too, just great.


Is the CEL for the Knock Sensor? It may go out for a short time but you can bet on it coming back until you fix the problem. (A bad knock sensor could lead to some major engine problems if you're using low octane gas...and the performance/mpg of your car is going to be HORRIBLE)

Hope any of this helps,
-Jeff


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## VQMatt (Feb 21, 2004)

By freewheel, i mean it just turns freely without going in. The CEL wasn't because of the knock sensor, it was because i took my IAT sensor off and disconnected my MAF when i took them off to clean my thottle body. I decided to check the codes and reset the light to see if i had any i didn't know of, and the knock sensor showed up. My CEL hasn't been on since i did that, and after reseting it, it hasn't showed up again.


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## Jeff (Oct 17, 2002)

If the piston on the rear caliper is spinning freely without going in then I would assume it is either pushed out from the piston chamber or needs rebuild. Either way it is best to just go ahead and rebuild it. Nissan dealers have a rebuild kit you can use for ~$30 iirc.

As far as your cel is concerned I think you're ok for now. The knock sensor will not always show a cel so you could definitely be in the process of having it go out anyday. But it may have thrown the code just because of the cleaning...but that usually isn't the case.


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## VQMatt (Feb 21, 2004)

where is the knock sensor located? Cause if it is going bad, i'm just going to ground it. Has anyone had problems grounding the knock sensor?


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## Jeff (Oct 17, 2002)

If you look down under your intake manifold, in the 'v' of the engine, you will see a black circle with a wire coming out towards you attached to the engine. This is if you are standing by the driver's front wheel.

It's a little hard to see but it's there...


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