Alternate Caliper to Scorpio Rear Calipers/hubs on XR

[DPDISXR4Ti]

Right now, what is being persued is the late 90's/early 2000's VW Passat caliper. I have some Jetta brackets, which I believe will work with the Passat caliper as everything else is the same between the 2.

And here it is mocked up. FWD Passat caliper, Jetta bracket, Focus rotor, Sierra Cosworth Hub, Scorpio bearing carrier and STA...





Here's the biggest issue. The pad rides about a 1/4" past the rotor edge. It would work, but obviously not right. Could be fixed by moving the through-holes in the bearing carrier downward. Not too sure I like that idea.




A minor issue is that the cable-end doesn't fit through the fitting, but the loop-end could just be cut off since it doesn't get used any way...

[timxr8]

Maybe the Cossie 273mm rotor will work? Depending on the height, measure from the rotor to the top of the pad, should be about 11mm to work with that, or if it's closer to 14mm for the Focus SVT. I'm thinking the Focus SVT will be too big diameter.

[DPDISXR4Ti]

Maybe the Cossie 273mm rotor will work? Depending on the height, measure from the rotor to the top of the pad, should be about 11mm to work with that, or if it's closer to 14mm for the Focus SVT. I'm thinking the Focus SVT will be too big diameter.

The Focus rotor is about 1/2" too small (maybe a little less), so a 273mm rotor would work, providing a safe margin at the rotor edge. But is the Cossie rotor the same offset? Of course my preference was to use a rotor commonly available in the States.

The bigger VW bracket (B5.5 Passat/B6 A4) pushes the rotor requirement out by 1/2". Add that to the 1/2" I'm rotor-undersized now (with the 10" Focus rotor), and the 11" Focus SVT rotor would seem to be perfect. Although this rotor isn't as widely available as the 10" Focus rotor, it's still readily available for short money. I just wish I had grabbed a pair of Passat/A4 brackets at the junkyard the other day. I don't think I want to take the ones off my daily driver A4, even for mock-up purposes!

I've posted this message on VW Vortex Forum just to make sure we're not missing some third option on caliper brackets...
http://forums.vwvortex.com/showthread.p ... st94441546

[timxr8]

...But is the Cossie rotor the same offset?

Yes. The only difference between the 2 bearing carriers (standard disc brake vs the Cosworth, both 2wd and 4wd) is the mounting height of the ears. The offset is identical. I know this from holding them in my hands.

[DPDISXR4Ti]

...But is the Cossie rotor the same offset?

Yes. The only difference between the 2 bearing carriers (standard disc brake vs the Cosworth, both 2wd and 4wd) is the mounting height of the ears. The offset is identical. I know this from holding them in my hands.

I'm confident the 273mm Sierra rotor would work with what I have mocked up now, but I just found a pair of 11" SVT rear rotors for $27 SHIPPED on eBay, so I ordered them. I'm confident they'll work with the Passat brackets, and it will be consistent with my approach of upgrading to parts which are readily available on North American soil. This way too, for anyone else wanting to go this route, you can just source the calipers w/ brackets from the same donor ('98 - '05 FWD Passat).

First item on my new junkyard shopping list...

'98 - '05 VW Passat rear caliper brackets

[timxr8]

The risk with the SVT rotor is the friction area of the pad is exactly the same as the height of the machined surface of the rotor. They have to be within 1mm of the height to work. Took a couple trial brackets to get the 13+ Cmax/Escape pads to match the surface. Interesting fact: the pad friction dimensions are identical between the VW and the Ford.

[DPDISXR4Ti]

The risk with the SVT rotor is the friction area of the pad is exactly the same as the height of the machined surface of the rotor. They have to be within 1mm of the height to work.

Well, I guess I'll find out how close my keyboard engineering is to reality. I'm probably a few weeks out until I can make another junkyard run. Might have to pull a caliper bracket off my A4 to do a quick test fit!

[DPDISXR4Ti]

An interesting data-point from the VWVortex forum I referenced previously....

If the bolt pattern for the MKIV caliper carrier has the correct spacing to bolt onto your car, the MKIII rear caliper carrier will probably fit better on your car with the MKIV rear calipers.

We have a similar spacing problem when fitting rear MKIV calipers on a MKIII (the caliper carrier bolt spacing is the same) but same as your Ford, the caliper outset is different, so the MKIV caliper carriers will not fit on a MKIIII. The MKIV caliper mounting bolts are also too short to work on a MKIII. Also, the late MKIII that came with rear disk brakes came with a weight bolted to the parking brake lever (to help it return when the parking brake cable is released) on the rear calipers that has a FOMOCO trademark on it. So apparently the MKIII caliper is used on at least one Ford Product of some sort.

When swapping MKIV rear calipers onto a MKIII, we use the MKIII rear caliper carriers, caliper mounting bolts, brake pads, parking brake cables etc... All MKIII parts except for the alloy MKIV calipers, and the hoses that connect them to the hydraulic system.

So now I also need to hunt down some Mk3 ('92 - '97) Jetta/Golf/GTI rear brake caliper brackets. These are going to be much more scarce in the junkyard since many of these cars came with drums.

[DPDISXR4Ti]

So now I also need to hunt down some Mk3 ('92 - '97) Jetta/Golf/GTI rear brake caliper brackets.

Looks like I'll have fun getting the 8mm Allen-headed bolts out of a Mk3 Jetta at the junkyard...

[In XS 7]

So now I also need to hunt down some Mk3 ('92 - '97) Jetta/Golf/GTI rear brake caliper brackets.

Looks like I'll have fun getting the 8mm Allen-headed bolts out of a Mk3 Jetta at the junkyard...

You can use an 8mm Allen wrench and a piece of pipe, it works for me most of the time.

[DPDISXR4Ti]

You can use an 8mm Allen wrench and a piece of pipe, it works for me most of the time.

I read of a couple people bending them with that approach, but it could be an option. I'll study my collection of pipes for a proper fitment.

[DPDISXR4Ti]

Just a couple minor data-points for anyone who might be junkyard-sourcing VW/Audi rear caliper brackets. Removing the shock (at least the lower bolt), may provide some much needed space to get a 1/2" breaker bar in there. A 21mm socket and open-end box wrench will be your friend in this endeavor. 1/2" drive 8mm Allen head sockets are available - you'll want a good one - Hazet makes a stubby one which is ideal - part# 986-8.

Removal of the caliper pins require a 13mm socket or wrench along with an open-end 15mm.

More recent VW's (Mk5 & Mk6) use 14mm Triple-square (XZN) headed bolts, but the caliper is a different design. Not sure if it's still 90mm ear spacing, but I'm not looking to chase after another solution right now. Plus, most of these more modern cars have electronically operated parking brakes.

[DPDISXR4Ti]

More details shortly with some test fitment results, but for those of you wanting to junkyard source your VW caliper brackets, these three tools (or something very similar) are a near requirement...

Snap-On 1/2" drive 8mm Allen socket part# SAM8E
Harbor Freight 1/2" drive extendable handle ratchet (part# 62311)
1.5" long 1/2" drive extension (for use on Mk3 bracket removal)

- Don't think that you can use a 3/8 drive socket with an adapter. You'll break the adapter.
- Don't think that you can use a lesser grade Allen socket. You'll round the corners off. As it is, if the bolts are really on there, you risk rounding out the bolt head with the Snap-On socket. At that point, you move on to another car.
- I'm sure you can get better grade extendable ratchets, but in this case, the Harbor Freight one is pretty good. I've abused it like a breaker bar on several occasions now and it's still as good as new.

[DPDISXR4Ti]

Finally made it back out to the junkyard to do some shopping for this project. I came home with two pair of VW brackets, one set from a '96 (Mk 3) Jetta and another from a 2001 (Mk5) Passat.

Neither is exactly what I need, but I now have a solution. First, the Mk3 Jetta brackets are useless. The data I got about them is wrong. They locate the caliper about the same radial distance from center as the Mk4 Jetta brackets I previously tried with the added "bonus" of being a 20mm offset rather than the required 38.

The Passat brackets are nearly perfect radial spacing for use with the 11" SVT Focus rotors. In truth, the pad hangs beyond the rotor edge about 1mm, but I think I can live with that. At least I'll never have issues getting a caliper off a worn rotor. The bigger issue is that this bracket is also designed for a 20mm offset. I can fix it with a simple 18mm thick pass-through spacer, and that's probably what I'll do. Heck, I'll probably just cut the Jetta brackets up, bore out the holes to 10mm and mill those to 18mm.

Pics of it all mocked up. Obviously the assortment of spacers were for test fitment. I also need to get some grade 10.9 bolts of this size... 10mm x 1.25 x 40mm

[DPDISXR4Ti]

A minor issue is that the cable-end doesn't fit through the fitting, but the loop-end could just be cut off since it doesn't get used any way...

Finally updating this thread now that I've been running this setup for a couple months. The above issue was easy to address. I just opened up the hole with one of those step hole saws. I think I opened it up to 9/16". The bushing on the Sierra brake cable needs this size opening any way. I think I used the VW retainer clip for the cable, so grab that at the junkyard if you think of it.