Rear Disc Brake Question

This looks a little different but should be a direct replacement.

 

http://www.socalautoparts.com/...attern-4x130-p-13513

 

Another from cip1.

 

http://www2.cip1.com/ProductDe...=C13%2D22%2D2841%2DB

Frank,

 

Clean up the OD of the rotor with a little emery cloth and you may find a part number.  I know that is where Empi puts them.  I think I may have a couple of 4-bolt Empi rear rotors that were never used.  If they are what you need, you can have them for shipping cost.

 

James

Agreed. Appears to be a '68-'79 rotor with its long snout.

OK. I checked the links you guys put up (thanks much).  Mine seems to be or have a recessed center 'snout'(that black co-centric thing in the middle of the assembly) I thought maybe that was something different.  I found out when I went to change brake pads in the rear that I had 914 calipers.  I'd sent in photos and Greg pointed that out.  I wasn't sure if I had something related to a 914 setup.  My pan is a '68 swing axle.  Are the rotors pretty standard as far as what will fit and work or could there be a lot of variation?

You are correct they look more like 914 rotors ---- where the center hub with lug nut threads is separate from the actual rotors.  If you undo the caliper from its hold bracket the rotor should drop off.  That might give you room to drill out center of the broken off lug bolt.

 

Ah, I think you're right. I assumed I was just seeing the "old wheel adapters" he mentioned still stuck to the rotor.

That's funny Greg because from the rear of the rotor it looks like what they guys indicated but if you look at the bolt hole it has a non-threaded part thats a few mm thick then threads.  I figured maybe some sort of hub in back but it almost appears that the rotor is solid and comprises the braking and mounting surface.  The rotor assembly appears to be one piece but it has several 'set screw' holes in the front of it. If you look at it from the rear the 'plate' where you see the bolt hole appears seamless from the rest of the rotor.  It looks like its part of the rotor to me and you can't really feel an edge.  I'm totally confused now as to what to buy to replace if the bolt removal goes south on me.  I took a few more pics...see if you can make anything out from these.  If not suggest a few more angles and I can get them. 

 

The second photo is the end of the bolt that broke off and the third the front hopefully showing what looks like a two-piece setup and the 'two-part' bolt hole. It looks like a continuous part from the rear but two parts from the front...or am I going nuts??

If it was two parts I could change the rotor without cracking the big nut....

 

Nah, Justin, the removal of those is what caused all this in the first place.....

 

BTW, were there kits out there that incorporated 914 stuff?  Was this a common upgrade to rear discs?  Nothing like buying a used vehicle, kit at that, and having to be a detective every time something needs to be replaced.  I had to buy a couple sets of bearings for the front before getting help to see that I had the larger bolt on my tie rod so I need the large inner wheel bearing to make things work....

There's no screws holding it on so it's probably rusted together. Hit it with some penetrating oil both front and back. Unbolt the caliper and move it out of the way of the rotor. Take a hammer (rubber, lead, or deadblow preferably at least to start) and give it a whack on the back side of the rotor, not on the actual vertical braking surface, but on the corner where it meets the horizontal part of the hat.

 

Other option would be to take a pick, screwdriver, or chisel and try to hammer/wedge it in the gap between the two parts at the inner circle on the front and try to pry the two apart that way. May require filing down any big gouges you make so things sit flat when you put them back together.

Frank:

 

Yes, many of these cars tend to be "Custom Builds", starting with buyer requests of the builders and if custom stuff isn't added before delivery then the buyer tends to add/replace stuff later on - look at a lot of what's been "upgraded" on other owners cars just over this past winter.

 

The 914 rear brake set-up was a much coveted upgrade because the rotors and calipers are a bit more robust than the typical Karmann Ghia or Super Beetle (neither of which had rear disks) and a step up from the usual after market stuff available, PLUS they had working parking brakes!  All of the other rear disk kits available do not have the separate hub and rotor - that's usually found on more costly set-ups but is really nice when you need to replace the rotors or have them ground.  You might take a look on Pelican Parts to see if they have them in stock.  BTW:  if you DO have 914 rear brakes, you might have 914 front brakes as well, and that setup is the same on the Porsche 924.  The 924 turbo had (I think) slightly larger rotors and calipers - someone else on here might have better info on that.

 

I'm sure if someone were to look around my car there would be a lot of things that didn't look "stock" (whatever THAT is on these cars!)  I would hope that the same person wouldn't look at what I've done and wonder "Why the hell did he do THAT?"

 

BTW:  I'm with Justin - The rotor is probably just rusted to the hub.  Remove the caliper out of the way, put a 2" X 4" block on the back side of the rotor and give it a damn good smack to loosen it up (and not mar the rotor surface).  You may have to rotate it 90° at a time and keep hitting it til it breaks loose, but it should with only a few smacks.  Some of those rotors had small dowel pins locating the rotor on the hub and they may be rusted on, too (although I didn't see any in the pics provided).

 

Good luck!

Personally - I'd put wheel on (or steel angle iron), remove the 36mm castell nut, pull caliper and then pull off entire rotor hub assembly (release hand brake).  You can then get to back to drill out lug bolt, use easy out or weld a nut on remaining portion.  Could take it to machine shop and I'm sure for $40 they'd get it out.

 

Here's write up on how to use 914 rear disc to replace bug drums.  I do recall there being a kit available years ago.

 

http://www.airsouls.com/how-tos/rear_discs.htm

 

http://www.gerrelt.nl/section-...ions-rear-disks.html

 

Those conversions are pretty slick!

I wouldn't rush out and buy any 924 brake parts. Regular 924s had 4 x 108 bolt pattern, the same as Audi 4000 back in the day. The 924 Turbo had 5 x 130 like the 911.

 

My friend Mike has figured out how to do 911 rear brakes on his 914-4 that has been turned into a 6, he'll need them!

Is this a good time to sing the praises of Neversieze? I put this on just about every thread i come across, esp'y lug nuts/bolts, splines, and so forth.  stuffthat sees the elements, and has to live there unmolsted for a LONG time.  i hope this gets resolved, there are several good options listed.  i like give it a good swift whack the best, but you get to decide. salvage the orig part if you can by removing the broke bolt.  then at least you know what you have left will fit.

Frank,

 

In one of the pics above it looks like the broke off stud protrudes out the rear. You should be able to remove the hub and extract that broken stud fairly easily. Armchair perspective of course!

 

...also, I'm almost certain that hub is one piece. The front is just a relief machined into it. Pull the fricken hub off, use some penetrating oil for a few days, clean off the oil, apply a little heat (a plumbers torch will do), try backing it out with a good pair of vise grips else use and easy out.

Did you get it yet?

Before I start using "Nevahseize" on anything, I always put a big dab of it in one hand and then rub it generously all over me, my clothes, my tools, the floor jack(s) and all four fenders of the car.

 

I never used to do this, but always found the stuff all over everything within ten feet of whatever project I was working on as soon as I was done, so I figured I would just get ahead of the mess and create it beforehand, just to get it done.

 

It works...

it might help catch those little brass thingies that pop out of your carburetors when you're working on them too.

and I can assure you that the stuff is also "nevah get it out of your clothes".  there is nothing that will get it out of fabric.  so, another word to the wise: be careful w/ it.  I do not recommend Gordon's pre-emptive tactics here. Might make him feel better, tho . . .

Thanks for all of the great suggestions. I do think that its a 914 setup since two years I had to replace the brake pads.  Greg pointed out that the calipers looked like 914-4 units and so I ordered the pads and they fit.  I did not expect the rotors and hubs necessarily to be from a 914 since sometimes other things get mixed in.  

 

I will get the rotor off and take a stab at the hub alone and get the bolt out.  I've juiced it every time I go by it in the garage. I'll take all the suggestions above to get that sucker out. If you look at the last photo above you'll see that there is the outer rotor, an unthreaded 10mm or so, then the threaded part where the bolt sheared off.  There are places for set-screws but none were used.  It appears that the rotor and hub are separate. Its all just held together by the lug bolts.  Ill post pics when I pull the rotor.

Gordon and Greg:  I wondered if there was a 914 conversion thing that was popular at one point as the car has been on the road since 1991.  Its back to the trying to find out whats on the car so I can replace things when required.  If this is correct at least I can get the right parts in the future. This has been a big help.

 

Rusty: No its not off yet but thanks for asking. I'll get a whack at it soon and one way or another it'll come out.

 

El Frazoo:  Any relation to the Great Kazoo??  I really want to salvage the parts since I want to go ahead an get those Fuchs wheels on there before the driving season starts up here.  I've drilled though the bolt (PITA) and will take care to save and re-tap the hole.

 

Danny: The hub has a 4x130 bolt pattern. Old 914-4??

 

Gordon:  I hear ya!  Every time I do this kind of job, or any job for that matter, I get covered in whatever.  Just like working with a caulking gun.  It never ends.

 

Frank, that looks EXACTLY like a 914 rear setup.

 

FYI, Rabbit/Scirocco had the little screw to fix the rotor to the hub. Most of the time they rusted/froze/snapped off. But they do make it a whole lot easier to line things up. My Audi has 18" wheels and lug bolts. Believe me, they are HEAVY and a real pain to line up. They don't have a provision for that little alignment screw.

 

And yes, Frank, the lug bolts hold the whole shebang together just fine.

As Danny said, they look like 914 stuff, and yeah, the lug bolts hold it together. In the '80s, 914 parts were the only way to add rear discs to your beetle or VW based car. I'm guessing early(?) '90's when aftermarket kits started appearing. In the late '70's/early '80's there was a guy with a bug from Portland, Or road racing at the local track (Westwood, perched amongst the trees on one of the local mountains and considered by all who raced there to be one of the more scenic tracks around; sadly, it's now covered in housing) running 914 rear discs.

 

 Hot VW's did 2 articles on the subject, the first (Dec. '84, Adapting 914 rear disc brakes to an IRS VW) giving dimensions for fabricating the caliper and emergency cable end mounts, and the 2nd (Jan. '85, Rear Disc Brake Installation) a kit with the pieces already fabricated for you. 

Can't quite tell from the picture but sometimes those holes are not alignment holes but threaded holes that allow you to screw in a bolt on either side to easily just push off the rotor. Just have to figure out what metric bolt.  

You're right Dale, but it looks like these rotors will pop right off.......

 

I know, famous last words.

Well, I got the damn lug drilled out and as Rusty mentioned, it did fall out the back of the hub once it met up with a big enough drill bit and enough WD-40 squirted in there.

The rotor will definitely come off.  Its settled that its a 914 setup.  That'll help when I eventually need to pruchase parts. 

As AL and Danny mentioned that this was an early conversion it makes sense since this car was originally registered in 1991.  It definitely is not a newer kit since it looks like nothing I've seen on the market recently.

 

Thanks to all for suggestions and playing name those parts for me.  It was a huge help.

Frank

DID YOU BUY A CAN OF NEVERSIEZE YET?

No need to yell.  I have not yet.  But don't I want adapters to 'kind of seize' so they don't come off and take my wheels with them????

I use it on spark plugs and stainless steel bolts - but leary on lug bolts.  On lug bolts they even say to check torque after 500 miles.  

Not yelling, sorry.  Fat fingers hit caps lock when I mean an "a" sometimes.  Plus using my remote tablet w/ keyboard, which is pretty cool, but still too small for my fingers.  Was intended as just a gentle reminder . . .

just kidding fraz (using my inside voice).  appreciate the advice.

 

Greg, They do indeed say to check torque after a certain number of miles.  Just to let things settle and stretch I guess.  My kid is studying engineering.  Maybe I'll ask him and try to get my money's worth out of him.....