# Mk 4 Jetta Rear Brake Piston Reset



## Clickman (Sep 24, 2006)

I cannot get my piston to reset on my one rear brake (have not tried the other yet).
I have the the special tool to turn it and push at the same time. The plate doesn't quite fit in so I have to get the piston in by hand a little bit. Even pushing as hard as I can while turning(clockwise) the piston wont budge. It just sits there and spins. I read somewhere else to try turning it counterclockwise until it stops and trying again to no avail. I also tried opening the bleeder valve while pushing and turning, it dribbles out a little but still doesn't go in. E-brake is off also. 
I'm not sure what to do now.


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## VWBugman00 (Mar 17, 2009)

*Re: Mk 4 Jetta Rear Brake Piston Reset (Clickman)*

The tool from Autozones loan-a-tool system worked great for my rear brakes. Its the 4th largest coin shaped one in the box, and it fit right up. Its a $55 deposit, which you get back when you return the tool. Be sure you get the one with the pressure plate that goes in the outside pad area. Brace the caliper in its mounting location with one of the bolts, turn the adjustment tool that adds pressure with a wrench, and twist the other one the other way with your hand. Should zip right in. That little square tool thing that you can buy is a piece of crap, it won't fit. If thats what you got, take it back. This is what you want:
http://www.amazon.com/Astro-Pn...uto_3










_Modified by VWBugman00 at 10:46 PM 6-22-2009_


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## germancarnut51 (Mar 23, 2008)

*Re: Mk 4 Jetta Rear Brake Piston Reset (Clickman)*

If you don't have a store near you that has a tool loan program, you can buy the caliper retraction tool set from Harbor Freight for $30, OR when on sale for $20.
Same price in a Harbor Freight Store, or Website: harborfreight.com, but then you have to pay for shipping.


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## Clickman (Sep 24, 2006)

*Re: Mk 4 Jetta Rear Brake Piston Reset (germancarnut51)*

http://www.cdupload.com/files/...8.JPG 
As you can see I have the Harbor Freight tool but it doesn't clear the piston. I worked on the other side and everything went nicely. I'm thinking the caliper is messed up. Also the boot got torn and it looks like it has to be taken apart to be fixed.


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## germancarnut51 (Mar 23, 2008)

*Re: Mk 4 Jetta Rear Brake Piston Reset (Clickman)*

Looks like the piston has been overextended.
Did you step on the brakes after removing the caliper from the car, and/or the pads?
I haven't had this problem before, and without getting a caliper out to try this... Have you tried using the tool without the plate? Will the tool jam against the caliper without the plate installed? Doesn't look like you need much more clearance to fit the tool in with the plate installed.
The caliper seal kit includes the piston ring seal, AND the piston boot. Order a caliper seal kit, and you should get the boot.


_Modified by germancarnut51 at 11:19 PM 6-23-2009_


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## VWBugman00 (Mar 17, 2009)

wow...how did you get the pads out? You may need a new caliper.


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## Clickman (Sep 24, 2006)

I'm going to get some steel plate, maybe an 8th inch and make a thinner backing plate that will clear it. There is no good way to secure the tool without it. If I can get the piston to reset I'll get the seal kit, if it doesn't I'll tear it apart and make sure the caliper can't be repaired before buying a new one. Either way it looks like I'm pulling the caliper. Although I did pull the ebrake again after everything was taken apart, it was after I already tried to fit the tool in. the brake hose felt pretty stiff when I touched it, can't it be pinched shut or do I have to plug the end with something?
I got the pads out by wiggling the carrier.


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## spitpilot (Feb 14, 2000)

*Re: (Clickman)*

Looks for sure as if the brakes were applied after caliper was removed..I"ve never seen a rear piston extended that far!...I"d bet the e brake adjuster is messed up by doin this and will not work properly (from what I"ve read here you mess it up you buy new caliper) even if you do manage to get the thing retracted enuff to install.


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## Clickman (Sep 24, 2006)

So I took the caliper off and apart. I still cant figure out how I was able to turn it without it going in. Both the piston and cyl are threaded. The piston slid back easily. The ebrake lever just pushes the threaded rod out a little, everything seems to be in working order. I ordered a new seal kit. I'll update when I get it and install it and take it for the first test run to bed the pads in.
Anyone know how much the brake system holds fluid wise?


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## kyle_b (Jul 12, 2007)

*Re: (Clickman)*

that sucks that you took it apart. the tool would fit if you put the cirlce piston adaptor on first, then put the rest of the tool in. i have to do this sometimes at work, my mac tool isnt the thin enough sometimes. The piston wasnt over extended, they do go out that far.


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