Frozen Rear Calipers

[Cousinphil]

Am I missing something here? I've never done Audi brakes before but I've replaced plenty of pads on lots of other vehicles and there was never any mystery to the process.

I've been garaging my 2004 during the winters so there isn't much rust. The 13 mm bolts came loose with the normal amount of force. The old pads were low but not extremely low. But the piston will not move.

I've had frozen calipers before but I usually just push the piston back in with a C-clamp and the calipers are good to go until the pads get low again.

At first I didn't even disconnect the E-brake cable because I didn't think that was necessary. When I couldn't move the piston even after putting a breaker bar on the C-clamp, I thought maybe removing the cable was a necessary step. But no, the piston is still frozen. Before I get the well-muscled buck who lives next door to come and wail on this C-clamp, am I missing something?

[IMG][URL=http://s722.photobucket.com/user/cousinphil207/media/Caliper_zpsukdwxkwy.jpg.html?filters[user]=143128332&filters[recent]=1&sort=1&o=0][/IMG]

[f0reignfeatures]

The B6 and most VW's from the same time require special tool to compress the rear piston. It's a cube looking thing, you have to attach it to a ratchet and turn it as you push down with. Search the forum or google it & you'll see what I'm talking about. I got mine from Sears for about $12. You can't do the job without it. Good luck!


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[Audibot]

You can't do the job without it.

You can, technically, but it's a pain in the ass. If you take the cap off the master cylinder reservoir, and then use a pair of thick/strong needle-nose pliers, you can push and rotate it in. It's not easy, but it's doable, considering I did the first 2 brake changes on my B7 that way.

[gilber33]

I replaced my rear pads amd rotors without any special tool. Used a pry bar to push the piston in with no issue. So, I wouldn't say you need the tool to do the job.

[imnuts]

You need to twist the piston while pushing it back in as others stated. A caliper press kit is very helpful for the rears. I picked mine up from Harbor Freight for like $40 when I did mine.

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[strtdrms]

Auto parts store will allow you to rent the tool with a deposit

[Cousinphil]

Once again, Audizine to the rescue. I'm glad I didn't get the young buck next door.

So I got the cube tool, $10 at Napa, and I'm able to turn the piston but I don't seem to be making much progress. It's hugely awkward to hold the caliper with one hand and push and turn the ratchet with the other. I would hate to do this with needle nosed pliers... Does the piston have a super fine thread? It is a right hand thread isn't it?

[johnwiz]

I can't remember which direction to turn while compressing them, but it does take a bit of effort.

I also got a kit like this, it's been great for doing a variety of different cars;

https://www.amazon.com/8milelake-21p...e+caliper+tool

They should have one to rent at an Autozone or such.

[5ktq]

I have the same or very similar Chinese set. Definitely worth the money, makes it painless.

[customa4]

Rent the kit johnwiz posted from Auto Zone. Give maybe a $50 deposit to rent it and you get all of your money back when you return it. Much easier with that tool.

[Cousinphil]

OK. I got it. I'm back on the road. I was able to accomplish it with the frickin cube tool. I lashed the caliper to the car and then I had both hands free. But I was still turning and turning and the piston wasn't going in any further. The trick was to use a big screwdriver to pry in the cube tool while turning it with the ratchet. The second rear wheel went much faster. I did have to remove a little brake fluid with an eye dropper. Thank you all for your help. A little information goes a long way.

But I can see a time in the not too distant future when I'll want to upgrade my brakes all the way around. These stock 245 mm disks are OK but not great. I could use a bigger vented disk. Something a little more high performance. Was there a sport package option for this model?

[fR3ZNO]

Best bang for your buck upgrade for the rears would be B6/B7 S4 calipers and rotors. They use a 300mm vented rotor.

A cheaper option would be to use B7 A4 rears, still a solid rotor, but use a 287mm rotor.

[Audibot]

Best bang for your buck upgrade for the rears would be B6/B7 S4 calipers and rotors.

Exactly my plan for my C5! Lol. Luckily I have a donor car...

[Cousinphil]

[QUOTE=fR3ZNO;11965133]Best bang for your buck upgrade for the rears would be B6/B7 S4 calipers and rotors. They use a 300mm vented rotor.

S4 calipers and rotors sounds like what I should have. Does that 300mm rotor fit inside the stock 16" wheel?

[fR3ZNO]

S4 calipers and rotors sounds like what I should have. Does that 300mm rotor fit inside the stock 16" wheel?

Yes, it does.

[Cousinphil]

I found a good thread on S4 brakes on an A4 from January 2010. An extensive discussion.

http://www.audizine.com/forum/showth...rakes-on-B6-A4

[fR3ZNO]

That's just the tip of the iceberg. There's ton of info on the forum about different brake upgrades for the B6.

[diagnosticator]

Only upgrading the front brakes with B6 S4 calipers and 345 mm rotors provides a huge improvement in braking power, with the rear brakes staying the stock 1.8T calipers and rotors. I can invoke ABS at will with my B6 S4 front brakes. B7 front calipers are practically the same as the B6 S4 calipers, with the caliper carrier dimension for a smaller rotor diameter. B7 A4 brakes all around is another effective option, besides B6 S4 brakes. B6 S4 brakes on the front with 345 mm rotors requires 17" wheels. I don't know for sure, but I suspect B7 A4 brakes will fit inside 16" wheels, with the smaller front and rear rotors compared to B6 S4 brakes.

[Charles.waite]

I replaced my rear pads amd rotors without any special tool. Used a pry bar to push the piston in with no issue. So, I wouldn't say you need the tool to do the job.

Uhh, you can't just push them straight in though. Unless you hate the e-brake and want to break the mechanism...

[seanf86]

Only upgrading the front brakes with B6 S4 calipers and 345 mm rotors provides a huge improvement in braking power, with the rear brakes staying the stock 1.8T calipers and rotors. I can invoke ABS at will with my B6 S4 front brakes. B7 front calipers are practically the same as the B6 S4 calipers, with the caliper carrier dimension for a smaller rotor diameter. B7 A4 brakes all around is another effective option, besides B6 S4 brakes. B6 S4 brakes on the front with 345 mm rotors requires 17" wheels. I don't know for sure, but I suspect B7 A4 brakes will fit inside 16" wheels, with the smaller front and rear rotors compared to B6 S4 brakes.

you can fit B7 321mm front brakes inside 16" wheels but not the 5spoke B5 style that I unfortunately have for winters for my wifes car that look like this, they require a 5mm spacer to fit up front.

[Cousinphil]

Uhh, you can't just push them straight in though. Unless you hate the e-brake and want to break the mechanism...

I'm having a hard time picturing what's going on inside the rear calipers. If you push the piston it won't go in. If you twist the piston it won't go in. You have to do both at the same time. ????????

[old guy]

Yes you have to do both at the same time. Push in and rotate the Piston clockwise at the same time.

[Nollywood]

I'm having a hard time picturing what's going on inside the rear calipers. If you push the piston it won't go in. If you twist the piston it won't go in. You have to do both at the same time. ????????

The wind-in tool compresses the piston as it turns. You can't just force it in, you'll bust the parking brake mechanism, which is a ratchet-like action.

[Spike00513]

I'm having a hard time picturing what's going on inside the rear calipers. If you push the piston it won't go in. If you twist the piston it won't go in. You have to do both at the same time. ????????

Yes. That's exactly what the special tool kit does.

IDK where the push force comes from though. I mean yeah there's resistance from the seal and tight fit but still.
This is one thing I noticed on B7 calipers. IDK if their twist mechanism is machined differently, but they seem to move easier. IDK if that's good or bad.

Not sure what car the pic below is from but I guess the idea is similar.

[5ktq]

The resistance is from the orifice in the master cylinder, you're pushing the brake fluid in the wheel cylinder back into the reservoir, through the abs stuff and MC.

[Spike00513]

The resistance is from the orifice in the master cylinder, you're pushing the brake fluid in the wheel cylinder back into the reservoir, through the abs stuff and MC.

Sorry, I didn't specify. I meant I noticed a difference in resistance B6 vs. B7, on a bench rebuild with the calipers off the car. At least with mine.

But yes, I believe that's why people say when compressing, to have the bleeder screw cracked open.

[5ktq]

Oh, I see.. No idea then!