Rear disc upgrade = NO parking brake!

[flomulgator]

So I got a new front parking brake cable installed today (old one was bent and had a seriously frozen nut), and took the time to dremel off all of the springs on each cable (per the original smallcar instructions). My thinking was that the arm wasn't actuating far in enough, just binding on the coil instead.

Well with no springs in the way I adjusted and adjusted and got the thing so damn tight that it took both arms to pull the lever up to one click
....and still the wheel in the air is loose as can be. There is still a little bit of travel left on the pivot arms but the combined resistance of those two brake springs at that point is absurd. And I'm really just working with like the last 20% of travel at this point.

So I feel pretty confident in declaring that something mechanical inside the calipers is not doing it's job. These brakes (and the springs next to them) are pretty rusty from what I presume is the PO doing a lot of beach driving. Perhaps the parking brake internal actuator is just borked? hydraulic brakes work fine FWIW.
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She's built like a steakhouse, but she handles like a bistro!

[Sodo]

[flomulgator]

I was definitely coilbinding before I did this work. I don't think the springs on the cable are necessary as they just double down on the force already provided by the Audi caliper spring. They're just a relic of the drum-brake setup; without them my e-brake returned just fine.

I should add the following statement because it has been the solution to other's parking brake problems:
Itt is not the cables. They slide freely by hand, and under incredible force the plastic "cups" do not collapse.

Anyways, Sodo your statement has really got me thinking that even if the parking brake is in good working order if it's not used for a really extended period of time in which the brakes wear down maybe it won't auto-adjust into range anymore?

Assuming it's the other thing, internal corrosion, I have seen a rebuild kit online. But damn if it look like a lot of work. Even just taking them apart seems like a PITA compared the assurance of just buying new/rebuilt parts. I'm not saying I have more money than time but I just have a lot going on right now to want to add "rebuild brake internals" to my list!
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She's built like a steakhouse, but she handles like a bistro!

[Sodo]

Possibly buy new calipers and do a cursory check, be sure they have the proper grease in the proper places. Sorry I'm on the road can't remember or link to the grease type. Maybe consider extending the actuator arms before install?
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'90 Westy EJ25, 2Peloquins, 3knobs, pressure-oiled GT mainshaft, filtered, cooled gearbox
'87 Tintop w 47k 53k, '12 SmallCar EJ25, cooled filtered gearbox
....KTMs, GasGas, SPOT mtb

[furrylittleotter]

I wanted to mention that when I was up in Lake Stevens junkyard scrounging ac parts I looked in an Aerostar and they have MUCH longer parking brake handles... Didn't measure, but interesting.

Neil2

[Luckyphil]

I dont know why you guys persist with a mish mash of parts to cobble together a rear disc brake conversion when the T4 Eurovan rear disc brakes work absolutely fab see the pics I posted. The handbrake works much much better than the shitty drums it replaced having no trouble holding at traffic lights on hills of all types (i have a manual trans). A mate has this set up on his syncro and raves about it. How hard is it going to be for the next guy to work out what parts to buy when servicing the brakes. Mine are all T4 eurovan off the shelf.

[Sodo]

Phil I agree, I don't understand why the T4 brake is not a contender here in the US. The Eurovan weighs 5200 lbs which compares well to a Syncro Westfalia (5000 lbs). Why in heck are so many kits from an Audi 100/5000 that weighs only 2400 lbs? It's pretty reasonable to assume that the brake from a 2400lb vehicle would offer only 1/2 the braking power of a unit from a 5,000 lb vehicle. And even the Audi folks complain about it being lame, so why did it ever gain traction for 5,000 lb conversions. Strange indeed.

One possible benefit is that the little passenger car brake might be better matched to the front/rear balancer, it might (by chance) perform well in a system where the proportioning valve has not been "adapted" too. I can't tell you anything about that part, probably nobody can (without a skid pad and a team of engineers).

(Pics of Phil's setup a few posts back http://www.thesamba.com/vw/forum/viewtopic.php?p=8033773#8033773 )

Can you put your van on ramps and see if it holds? (Plz see different thread for PARKING BRAKE TEST ) Mine holds now (barely) but I had to lengthen the actuator arms to be almost as long as your OEM T4 arms. Not many folks are willing to do this test and post it, I think only the ones that hold will post, and so far that's me (with lengthened arms) and the OEM drum brake fellas are willing to test & post. It's a very easy test if you have ramps. Just neutral, on level ground, rear wheels partway on the slope. Also your wheel size AND the total outside tire diameter is interesting.
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'90 Westy EJ25, 2Peloquins, 3knobs, pressure-oiled GT mainshaft, filtered, cooled gearbox
'87 Tintop w 47k 53k, '12 SmallCar EJ25, cooled filtered gearbox
....KTMs, GasGas, SPOT mtb

[WLD*WSTY]

[FrankenSubySyncro]

[Jon_slider]

[Luckyphil]

Dont know about video but will post pics of the van holding on ramps as per the "ramp test" mentioned above. I have not done anything with the proportioning valve nor has anyone else i know who have this kit as we have not needed to. I have had to hit the brakes in anger only once on a dry road to avoid a rear end collision as i was not concentrating and the van pulled up real nice no nose dive at all. The kit I have is not comercialy available anymore as the engineer who designed it 10 years ago is now deceased but I met a guy at The Australian VW nationals and noticed he had rear discs which didnt look like the Aus designed Sherman (poor ebrake) nor the small car kit. Convinced him to have some sets reproduced as he was restoring rear suspension of his van. The guy runs his own shop see here
http://exoticars.com.au/ his name is Mark and he ended up getting 15 sets of adapter plates made up of which 6 or 7 are now sold.

[Jon_slider]

fwiw I believe
http://burleysmotorsports.com
offers the Eurovan disk brake upgrade

contact him directly if interested. I am not affiliated.
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My Soapboxes: Inflation; Handling; Gearing; Decoupling; Swepco

[flomulgator]

[Butcher]

Not only are the V8 rear rotors larger in diameter, they are 10mm thicker too. Since the brake pads are the same for both models, the caliper must be at least 10mm wider to accept the additional thickness of the rotor.

[flomulgator]

Well crap on a stick. Butcher you are absolutely right about the width being slightly different too. I could run these for now because they fit but I could never get new pads on! At this point I'll have to return the Quattro Sedan brakes I have and order the V8 Quattro ones. Thanks for figuring that out Butcher, it's taken essentially forever to figure out what calipers SmallCar is using!

Also some updates: my actuator on my parking brake mechanism is definitely borked. One actuator rotated free (with the spring off) for almost 2/3 of it's range and then moved the piston just a little. The other side rotated free through it's entire range, with no effect on the piston. Clearly the little screw inside is all messed up. The new brakes move the piston A LOT more, even with the spring still installed.
Also the inner lining of my parking brake cable on one side is tearing off, which caused the line to more-or-less seize. I know I had it moving 6 months ago when I first worked on this (and posted the pics on the previous page), and I was able to get it moving again and lubed up. However clearly they will need to be replaced at some point, for if I get the parking brake working again and use it in the winter such a setup could easily freeze solid with ice.
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She's built like a steakhouse, but she handles like a bistro!

[wesitarz]

The Girling caliper stamped 4143 is correct for the 90-94 Audi quattro V-8. The rotor is from the 91 Audi 200 Quattro 20v. Smallcar recommends the Zimmerman rotor. I tried the Centric equivalent 269 x 20mm (Made in China) from Rockauto when I couldn't source the Zimmermans, but the carrier hits the rotor. I tried shims but the rotor cracked when I torqued the wheel on. (PING is what you hear) Tossed them in the recycle and found the Zimmermans (Made in Germany) at FCP Euro at a 50% clearance price and they ship to Canada (FedEx) I will put them on in the spring.

[flomulgator]

My rotors are fine so I don't need to worry about this right now but still now I'm confused. Why would the rotor be from the 200 Quattro when the brakes are from the V8? Butcher just mentioned that the V8 calipers are 10mm wider than the 200 Sedan version I got and he's right about that. The Sedan version barely fit over the rotor on my van with worn pads. Is the Quattro 20v rotor different than the Quattro Sedan, and the v8?
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She's built like a steakhouse, but she handles like a bistro!

[wesitarz]

I did not know that the SC setup was a mix and match. I asked SC what pads I could use,then assumed the rotors were from the same 90-94 Quattro V8.They are not,having a much taller hub and offset. You want 269mm x 20mm vented Zimmermans from the 91 Audi 200 quattro 20 v. Other than Zimmermans may have some irregularities that throw the fitment off. Probably just as easy and as cheap to get the old rotors turned once.

[mozcar78]

The clarification required here is to mention that the rotor height is what calls for the a 91 200 Quattro Rotor OEM #: 447 615 601A vs the 91 V8 AUdi rotor. The difference is between 46mm vs 59mm. There is also a 49mm rotor height to throw in the mix. You just have to check all the iterations of these models to find the right one.

Our setups typically call for a 46mm Rotor Height. Front and Back. I have a long write up on google drive with this info all sorted out. BTW, This is with a 4143 90's Audi caliper. There is also a 38 Audi Caliper and a 43 Audi Caliper from the 1999 Audi A8. Yes there are a ton of options!!!!

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89' Vanagon GL 'Free Candy' Edition
81' Rabbit Truck

[masuda]