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Discussion Starter · #1 ·
I will be replacing my rear brake calipers this weekend. My replacements came with mounting brackets. I have been working from an Audi B5 manual I found online because I do not have the Bentley. Also I found this neat DIY: Rear brake job, caliper removal, rotor replacement, and rear wheel bearing replacement.

Regarding the caliper mount/carrier bracket the Audi manual says tighten differently depending on bolt appearance:
bracket upper: ribbed bolt 70 ft-lbs, socket bolt 44 ft-lbs
bracket lower: ribbed bolt 70 ft-lbs, socket bolt 44 ft-lbs
The DIY just says 70ft-lbs.
How do I know if I have the socket bolt or the ribbed bolt?

Regarding the banjo bolt the Audi manual did not have a torque spec (that I could find) and the DIY says tighten differently depending on color of washer:
If silver aluminum seal: 33 ft-lb
If black titanium seal: 28 ft-lb
Each replacement caliper came with two copper washers.
What do I tighten the banjo bolt to with the copper washers?

I searched for both these questions but couldn't find anything. And does anyone "pre-bleed" the calipers like the Audi manual says? (Basically where you tilt the caliper up and pour brake fluid in through the bleeder until it comes out of the hole where the banjo bolt goes.) Anything else you guys think I should watch out for please let me know, this is my first caliper replacement. Thanks
 

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Socket bolts are internal, like an allen, torx or triple square. You should have normal 6 point bolts, so go with 70ft/lbs and use Loctite. I don't know the torque offhand on the banjo bolt as I just tighten with a regular ratchet, I would go with 333ft/lbs.

I do not pre-fill the calipers, I expect most of it would leak as you try to attach the banjo bolt. I suppose you could add fluid through the bleeder after the caliper and hose is in place.
 

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Yes, 33, not 333. I do not cycle the ABS and I have flushed many brake systems on Passats along with swapping reservoirs.
 

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Discussion Starter · #5 · (Edited)
I replaced one of the rear calipers yesterday. I used 6 ft-lbs on the bleeder (replaced with speed bleeder), 33 ft-lbs on the banjo (washers were not removable) and 44 ft-lbs on the carrier mounting bolts. For the carrier mounting bolts I used a substitute 10.9 20mm flange bolts from Autozone and blue loctite. No VW dealer around me stocks the mounting bolts (N90688901 or N90688902) and I didn't feel comfortable reusing the old ones given the work it took to get them off. The reason I used 44 ft-lbs for the new mounting bolts is because the bolts that were on there originally were 10.9 10mm bolts with the hex/allen head. So since those are socket bolts and I replaced them with the same equivalent in hardness I went to 44 ft-lbs. The maximum torque for a 10mm 10.9 bolt I think is like 55 ft-lbs so I'm not sure where 70 ft-lbs comes from maybe those are harder black oxide bolts or something. If anyone has the bentley or elsa for the B5 and can elaborate on the rear caliper mounting torque discrepancy for FWD cars (ie not 4motion) that would be helpful.

It took a while to get fresh fluid out of the caliper. I did not pre-bleed. I didn't know how much to bleed so I bled like 8oz. I have to replace the other rear caliper and I think I will bleed them all at that time. I picked up 2 32 oz bottles of valvoline dot3/4 so I hope that's enough. I really didn't see a difference in color when I bled, but that's probably because I had been continually adding fluid over time due to the old leaky caliper.

Edit: I've since checked the Haynes B5 repair manual and it says 70 ft-lbs for the carrier mounting bracket bolts and doesn't mention socket type bolts. Also it shows that the washers on the brake line can be removed along with the banjo bolt. I was not able to do that but I guess it might be possible. It suggests stop the line from leaking by using a short piece of tubing that will tightly fit in the hole after removing the banjo bolt. I'm sticking with the Audi manual on the torque but I'll try plugging off the brake line next time like it suggests.
 

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I replaced one of the rear calipers yesterday. I used 6 ft-lbs on the bleeder (replaced with speed bleeder), 33 ft-lbs on the banjo (washers were not removable) and 44 ft-lbs on the carrier mounting bolts. For the carrier mounting bolts I used a substitute 10.9 20mm flange bolts from Autozone and blue loctite. No VW dealer around me stocks the mounting bolts (N90688901 or N90688902) and I didn't feel comfortable reusing the old ones given the work it took to get them off. The reason I used 44 ft-lbs for the new mounting bolts is because the bolts that were on there originally were 10.9 10mm bolts with the hex/allen head. So since those are socket bolts and I replaced them with the same equivalent in hardness I went to 44 ft-lbs. The maximum torque for a 10mm 10.9 bolt I think is like 55 ft-lbs so I'm not sure where 70 ft-lbs comes from maybe those are harder black oxide bolts or something. If anyone has the bentley or elsa for the B5 and can elaborate on the rear caliper mounting torque discrepancy for FWD cars (ie not 4motion) that would be helpful.

It took a while to get fresh fluid out of the caliper. I did not pre-bleed. I didn't know how much to bleed so I bled like 8oz. I have to replace the other rear caliper and I think I will bleed them all at that time. I picked up 2 32 oz bottles of valvoline dot3/4 so I hope that's enough. I really didn't see a difference in color when I bled, but that's probably because I had been continually adding fluid over time due to the old leaky caliper.

Edit: I've since checked the Haynes B5 repair manual and it says 70 ft-lbs for the carrier mounting bracket bolts and doesn't mention socket type bolts. Also it shows that the washers on the brake line can be removed along with the banjo bolt. I was not able to do that but I guess it might be possible. It suggests stop the line from leaking by using a short piece of tubing that will tightly fit in the hole after removing the banjo bolt. I'm sticking with the Audi manual on the torque but I'll try plugging off the brake line next time like it suggests.


Thanks for this information. I am currently getting ready to do my complete brakes and rotors on my 05 1.8t Passat and made my first attempt yesterday. Looking at your specs for the caliper carrier bolt I didn't find "10.9 10mm hex head" for the rear carrier. I typed in the oem part number and came up with this actual specs for it... https://www.ecstuning.com/b-genuine-volkswagen-audi-parts/allen-bolt-priced-each/n90688902/

I also cross checked with what they would have at autozone and typed in M10-1.25 x 20mm bolt and came up with this one... https://www.autozone.com/nuts-bolts-and-washers/bolt/needa-parts-m10-1-25-x-20mm-bolt/550987_0_0

Would the replacement for the bolt be correct with the one I posted from autozone?

I attempted to remove my rear bolts and found the proverbial rust and crud monsters wouldn't allow me to do so as I tried to remove them with 2 8mm hex sockets and broke both sockets while using a breaker bar to try and break them free. Lesson learned I saturated them in liquid wrench and will try again in a day or 2 to see if this helps while also adding heat to them before attempt as I have seen done in videos and other thread suggestion. I don't want the same headaches with the the hex bolt and will convert them out IF I ever need to do rotors again. Thanks for any help and clarifications.

Am I also correct in that the front caliper carrier bolts are 7mm hex ones and if so what are the autozone equivalents if at all different?

Thanks for the information and answers.
 

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Discussion Starter · #7 ·
Yes the OEM bolt has a 10.9 stamp. I used autozone bolts that are different from what you linked to since they are the flanged version of the 10.9 M10x1.25x20. I chose flanged because there is more mating surface. Mating surface helps prevent a fastener from coming undone under vibration. Also I used blue loctite which should add to the breakaway torque required to loosen the bolt. I tightened to 44 ft-lbs and let's say now cured it probably would take at least 55 ft-lbs to loosen.

Finding bolts at autozone is no picnic. Nothing was where it should be so I had to go through the racks. I ended up going to 2 autozones. Each showed them as "in stock" but only had one package. I had to buy two packages since I needed 4 bolts.

I've since bought a Bentley manual which says socket head rear carrier mounting bolts on the Passat B5 are supposed to be tightened to 70 ft-lbs. That contradicts the Audi A4 B5 manual but we don't own Audis, we own Passats. (The manuals are usually pretty close though and only the Audi one I linked to earlier can be found online which is why I was using it.)

70 ft-lbs is more than the recommended max torque for an m10 10.9 bolt, it almost seems like a torque-to-yield bolt spec but the manual doesn't say anything about not reusing them ("always replace"). If I do any more work in that area I'll probably use fresh OEM bolts at 70 ft-lbs, always replace, and that's my advice to you. They're 3 dollars each if you order them online. audiusaparts has free shipping (I've been using them a lot lately for small things) and they stock the bolt.

The OEM bolts also have a serrated mating surface which I'm sure adds to the breakaway torque. Like you I lost a regular 8mm hex bit. I switched to an impact grade one that worked. You might also try spraying the liquid wrench or whatever on the other side with the very end of the bolt, it may wick in better.

Note the link is dead for the DIY in the first post, but here's a cached copy from the internet archive's wayback machine:
Rear brake job, caliper removal, rotor replacement, and rear wheel bearing replacement (cached copy June 02 2018)

And here are some pics from the manual that should help:


97910




97911



Note "self locking" guide bolts referenced to usually means needs blue loctite. I've yet to see a self locking guide bolt that had some other method of locking (like distorted threads).

If you are not replacing the caliper you'll need to wind in the piston on the existing caliper since it extends over time and you'll never get new brakes in unless you do it. As you can see above it requires hooking onto the piston with a special tool and rotating it clockwise. I bought one of those tiny generic square piston rotator tools and used it with a huge c-clamp. I had to modify the nubs on the square with a dremel so it would fit into the OEM pistons. My advice to you is skip that and ask them for the loaner tool which is the real tool. You will have to put down a deposit but it's worth it. I really lost time cheaping out.

Finally to your question about the front brakes, the 1.8T and 2.8 (V6) of all years 98-05 use caliper assembly FN3 and the carrier mounting bolt is a "ribbed combi bolt" (whatever that is) tightened to 89 ft-lbs, that the manual explicitly says can be reused after cleaning the ribs. I doubt it's something you're going to find in autozone with the generic bolts, you'd probably have to ask them to special order. The caliper is bolted to its mounting bracket using what looks like special guide pins at 18 ft-lbs, different from how it's done in the rear.
 

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Discussion Starter · #8 ·
My left rear caliper, Raybestos FRC11076, went bad after 5 months. There was a leak at the piston. I bought a replacement caliper w/bracket from Advance Auto Parts. It is a Wearever 19-B2109 which is probably a reman by Cardone. The leak was bad and I needed to change it right away so once again I found myself in the position of not having the right carrier mounting bolts. Ignoring my own advice I used some new 10.9 M10x1.25x20 that I had left over from Autozone. I used blue threadlocker and tightened to 60 ft-lbs.

Also one thing I've found working on the calipers is how hard it is not to cross thread the banjo, I've had trouble with every one getting them started because the hose is so stiff I can't really angle the bolt properly.

Also note the Bentley doesn't have torque setting for bleeder but I found a service action from VW for a later year Passats that says tighten to 10Nm (7 ft-lbs) which is pretty close to the 6 ft-lbs I've been tightening them to.
 
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