Hubs & Brake Swap Complete!

[PRY4SNO]

Big shouts out to Jordan (The Jerbel) & especially Mike (mikekrus) for their invaluable assistance, without which not much of this build would ever get completed, quite frankly.

Not sure how many of the problems we encountered resulted from massive reading fail on my part, or shitty DIYs that litter the Internet. Either way, this conversion was anything but plug'n'play. Source new this, have that machined, break/replace/modify this, wait for that. Frustrating, time consuming, expensive, & ultimately... incredibly rewarding. She just looks so much better than before.



Rolling once more, I'm okay with the fact that the brakes don't seem to want to hold pressure. We thoroughly bled the brakes twice. Pedal still just goes to the floor before there's any bite in the brakes. It's all good though... I have rolling issues now, instead of non-rolling hangups.

One theory is that the low-quality/wrong blend Prestone Dot 4 brake fluid is responsible. Odd, yes. Unlikely, no. When I replaced the power steering pump and refilled with Prestone mineral-based PS fluid it seized the brakes and nearly ruined the pump. Wrong spec. Flush with VW/Audi mineral-based fluid and refill, magic. (The brake booster works off the PS pump.)

Maybe the brake master or booster is pooched. Possible. Car is 21 years old, after all. And the brakes felt soft-ish before I took her off the road the last time.

Ideas? Theories? Questions? Comments/criticisms?

[stef2.7t]

Re: Hubs & Brake Swap Complete!

Looking great thus far!

[All_Euro]

Re: Hubs & Brake Swap Complete!

There is a brake booster upgrade for your ride - send you the details when I get them… should be in the $350 range. I guess 034 used to sell them. Someone else post if you know

[PRY4SNO]

Re: Hubs & Brake Swap Complete!

Looking great thus far!

Thanks Stefan I know I promised you a ride, I'll offer it when we have some fresh snow and my brakes work up to par. Promise.

And thanks again for helping out with the calipers. A little TLC and I'll have myself some dandy spares.

There is a brake booster upgrade for your ride - send you the details when I get them… should be in the $350 range. I guess 034 used to sell them. Someone else post if you know

Thanks Monty for the heads-up! I'll have to read more into the ins-&-outs... but the hydro-assist-->vacuum-assist brake booster swap looks like the way to go!

[PRY4SNO]

Re: Hubs & Brake Swap Complete!

So, now that I'm rolling I figured I'd provide a retrospective of the work required to perform this swap.

Cliff Notes precede an illustrated walk-through of the headaches (read: time wasters ) encountered along the way.

Front:
-- Porsche BoxsterS calipers (Brembo 4 piston), pins filed down 1mm each as per 90quattrocoupe's DIY
-- 034/Apikol RS2 caliper bracket, + 3mm spacer machined to fit
-- S/S lines (custom made locally, Edmonton Brake & Clutch... highly recommended)
-- Euro A/S8 rotors (323x30mm), spun down inside to clear control arm, and 3mm spacer machined to fit behind rotor on hub
-- UrS4 hubs with new bearings, machined to fit (5mm off the radial axial shoulder)
-- H&R 5mm hub spacer to fit 235/45-17 rubber (225 max without spacer) up front
-- Installed front upper strut mounts... while I'm in there...

Rear:
-- B5A4q rear hubs, with new bearings
-- New lower ball joints, while I'm in there...
-- B5S4 rear rotors/pads, calipers & caliper brackets... e-brake cable bracket reamed to fit
-- S/S lines (custom made locally, Edmonton Brake & Clutch... highly recommended)... existing were 2" too short




If I would have used the entire B6 rear hubs and brakes assembly with new bearings I would have been okay.

B6 rear caliper & bracket:


Some machining is required on the inside shoulder of the rear B6 hub but it would have been cheapest overall. (Because I had them sitting there.) Since I didn't know if they'd match up or not I went the online DIY route.

However, I misinterpreted what I read and encountered a few surprises.

First, a lower rear ball joint boot was torn and required replacement.

Next, I thought that I could just re-drill the rear rotors to fit B6A4 rear calipers/brackets. Or even use the B6 rotors too.


No. :( The hat-offset (=B5) was all wrong.


So.

My friend Mike sourced a set of B5S4 rotors and pads for just $40 from a local with a monster 3L S4.

Lots more heat-sinking meat on these rotors...



B5S4 rear (left) vs. B6A4 front (right):


ECS wanted $180/bracket, $270/caliper + shipping & duty. Shokan wanted $180/caliper+bracket with a $35 core-charge. FTL.

So I phoned/surfed local at euro-wreckers ($75, but only one caliper), and eurodrivers.ca to no avail... then genuineaudiparts, audifans, and AZ, Motorgeek, and finally the object of last resort... vwvortex classifieds. Where I promptly found a set for $100 plus shipping, and another for $180-shipped. I used the former deal for leverage on the latter. Expedited international shipping at $80, for a cost of $180 delivered. Deal.

Of course... drama ensues and long story short I waited two weeks before asking WTF? He says 'no money, no calipers.' So I send a PayPal confirmation number, his excuse is he forgot to check his 'other' email. The brakes arrived in a week and change.

Upon fit up, there are a couple issues. The e-brake cable bracket needs to be notched to allow for the thicker diameter OEM Cq cable.



And the OEM brake lines are too short. There are a couple options to deal: 1) bend & re-mount the OEM hard lines to maybe gain enough slack & re-use the OEM rubber lines, or 2) disassemble at the OEM hard line and have custom braided s/s lines made about 2.5" longer.

Custom lines it is.




Meanwhile, as hangups would occur in the rear, the fronts were in full flight themselves.


Clearance, clearance, clearance! That's the number one issue up front.

The Apikol/034 machined RS2 caliper bracket (which is a very nice piece) needs a shim to clear the gap between the upright and caliper. They're made for Big Reds, 996TT calipers, not 993TT... and certainly not 996C4S/BoxsterS calipers. :( At this point I'm going to suggest that if you're going to do this mod, it's cheapest and easiest overall to have your machinist make this bracket for you out of steel (or aluminum should you be feeling spendy). You'll be bringing in a few parts for machine work anyways. Including the caliper bracket, for shims. Unless you cheap out and opt for stacking washers, which looks cheap.





Of course, the hubs themselves need machining to fit. I opted to use UrS4 hubs. To eliminate any confusion I supplied the original Cq hubs and told him to make the new ones fit the same. Worked like a charm.


Among the parts needing machining at the same time is the euro A/S8 323x30mm rotors. They'll need to have a couple mm's turned off the inside to clear the control arm. Next, a couple mm spacer in-between the hub and rotor is necessary to line up inside the caliper.


During all this time under the car, I did notice it looks pretty fresh underneath. <3


Since the strut housing is essentially hanging, this was an ideal time to finally fix the existing ones which are beyond worn out. Fragments come out, 034 Street Density upper strut mounts go in.

And then, the other thing (which I half expected) was my 235/45-R17 winter tyres *just* rub the control arm. Half expected because the max size I typically read of people installing is 225s... so that's not exactly a blindside. Luckily, the 5mm wheel spacers cleared enough... but I think I'll send them rearward and get 10mm up front to keep everything flush looking.

She does look pretty good to my eyes, even for all the road grime on the wheels.

[The_Jerbel]

Re: Hubs & Brake Swap Complete!

Looking great, Dustin! Sorry about all the machining that had to go into the brake parts, but the car is looking awesome now that it's all done!

[R_Ethug]

Re: Hubs & Brake Swap Complete!

sick!

[4rings]

Re: Hubs & Brake Swap Complete!

Ive been watching and reading lots of the stuff here I just never post but I felt compelled to reply to your thread.
I can't believe your doing all this work to your car. How many hours do you think it took you to do the whole thing? What did you use to get the old hubs out, torch and hammer?

[PRY4SNO]

Re: Hubs & Brake Swap Complete!

Looking great, Dustin! Sorry about all the machining that had to go into the brake parts, but the car is looking awesome now that it's all done!

C'est la vie. Half of the machining was expected & half the rest was half-expected, so all in all... much of the blame/hassle is my fault for not accurately comprehending what I read in the various DIYs that litter the interwebz. Not having the practical experience to differentiate what I was reading would be partly to blame as well.

sick!

Haha, that's like your catch-all comment for my threads Ryan! Glad you like tho, from what I can tell we're both OEM+ kinda guys...

Ive been watching and reading lots of the stuff here I just never post but I felt compelled to reply to your thread.
I can't believe your doing all this work to your car. How many hours do you think it took you to do the whole thing? What did you use to get the old hubs out, torch and hammer?

Thanks a lot! I appreciate your kind words.

If you think this is a lot of work on the car, wait until you see the next few stages before I begin to amass parts for a big-boy turbo build...

Took about 20 hours with the couple tries to get the brakes bled and all. Budget about 12-20 I'd say, or 3-5 hours per corner, inclusive.

Hubs came out with weasel piss, torch hammer and a press. Best way is to remove the upright from the car first, and remove the hub & bearing from the spindle using a press.