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2000 VW Jetti Rear Brake Caliber
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customcoloreffex
Novice
Nov 25, 2006, 10:40 PM
Post #1 of 6
(2946 views)
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2000 VW Jetti Rear Brake Caliber
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2000 Volkswagon Jetti 2.0 Auto, Four-Wheel Disc Brakes. I'm having problems twisting the caliber piston back into the caliber to install new pads. The set up is basically the same as a late-70's GM rear disc brake caliber. It has a lever on the rear that is mechanically operated when you apply the parking brake to apply the parking brake force. So in order to install new pads you have to twist the piston back into the caliber. The VW has the same type of system but I can't turn the piston to draw itself back down. The reason is, from what I can tell, the threads in the piston spin. Meaning you can hold the piston still and grab the threads with pliers and turn it. Quite freely I may add. So as I attempt to "twist" the piston back down it just spins and the threads don't grab. You're just turning and turning. So I took the right side caliber off the car and twisted the piston out. I removed the dust boot and the piston seal and I can twist the piston all the way down into the caliber. But once I put that piston seal back in it'll just turn and turn. I ended up taking the "guts" out of the back side of the piston and tried to get the piston into the caliber and I can barely get it in a quarter of an inch. The bore and the pistons surface are not scored in any way and the seal fits on the piston loosely but not excessively loose. What am I doing wrong here? Why would the pistons internals move freely from the piston itself? I've done plenty of GM rear calibers and they twist down without many issues aside from dirt and rust. That is about all the information I think there is to display. Thanks for any and all help!
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steve01832
Veteran
Nov 26, 2006, 2:34 AM
Post #2 of 6
(2942 views)
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Re: 2000 VW Jetti Rear Brake Caliber
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There is a special tool used to return the piston to its bore seat. One part of the tool spins the piston while the screw forces the piston down into the bore. Some makes require the piston to spin clockwise and some spin counterclockwise. My concern is that you took the caliper apart. You may encounter leaks if you disturbed the seal. You may end up replacing the calipers anyway. But, check to see which direction the piston turns as the forcing screw applies pressure and try again.
Steve
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Tom Greenleaf
Ultimate Carjunky
/ Moderator
Nov 26, 2006, 3:03 PM
Post #3 of 6
(2940 views)
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Re: 2000 VW Jetti Rear Brake Caliber
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I am worried like Steve said that the brakes was taken apart without new seals. Keep an eye on it.
Rear disc brakes are a bad idea for almost all cars and complicate parking brake engineering. Brakes in the rear catch all the road junk spit up from the front wheels and tend to fail sooner than the from which is doing most of the work.
Drum brakes just didn't have a lot of problems, T
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darrin
User
Nov 26, 2006, 6:51 PM
Post #4 of 6
(2937 views)
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Re: 2000 VW Jetti Rear Brake Caliber
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they dont make them like they used to. i agree with tom there.
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customcoloreffex
Novice
Nov 28, 2006, 12:34 AM
Post #5 of 6
(2929 views)
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Re: 2000 VW Jetti Rear Brake Caliber
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Well I was able to reassemble the caliber and get it installed on the car. I was worried myself when I took the piston out. It ended up being quite a hassle though. I had to use a C-clamp and a pair of locking pliers to grab the piston with. I've worked on cars for many years of my life, those mainly being GM though. And most of that time it has been the first two generations of the Camaro and Nova and other muscle car classics. So this Volkswagon's caliber resembled a GM rear caliber with parking brake. But instead of just twisting the piston down into it's bore I had to use a C-clamp to apply pressure and locking pliers to grab the piston. It took near to fourty minutes to complete the process. As I twisted the piston with the pressure on it it would move 1/64 of an inch. So then I would apply a little more pressure and twist and it would move in another 1/64 of an inch. And so forth. A turn of the C-clamp and about ten rounds on the piston. So it went like that, 1/64 of an inch at a time and a total of about 200 turns on the piston. I used a new seal and a new boot and mounted it. Connected the hose and cable, bled it thoughly, checked for leaks, checked for proper parking brake function and did a road test to check for and pull and any other leaks or problems. I ended up delivering the car last night and the owner reported no problems. I'm going to recheck everything in a few days to make sure, but for now there's no problems present. Parking brake is fine, no fluid is leaking and no dredded brake light on the dash from the prop. valve. I love this site so I though I'd share this to maybe help someone else who had my experence. Thanks all for the time and thought and I will see you all soon. Good Bye from Dallas Texas!
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steve01832
Veteran
Nov 28, 2006, 3:54 AM
Post #6 of 6
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Re: 2000 VW Jetti Rear Brake Caliber
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If you had to turn the pistons with locking pliers there is a very good chance you left sharred edges on the outside of the piston. As the caliper piston moves one of these edges can tear the outside boot. That can have bad consequences down the road. If this was one of my customers' cars, I would have replaced the calipers. Saving a few $$ now is not worth the liability of brake failure or at the very least, scarring your reputation as a mechanic. Just my opinion.
Steve
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