914 rear 5-bolt problem

[JmuRiz]

I have a 914 5-bolt kit that's being installed and the rear caliper will not fit on the 914/6 disk that I was given. Any ideas on what to do. I'd rather not have to machine down a brand new 914/6 rear disk.
Has anyone else had this issue? Thanks

Nathan

[Bleyseng]

Use a dremel to grind the inner face of the caliper to get the clearance. It's only a few mm.
Geoff

[Dave at Pelican Parts]

Yup. This is a known problem which only seems to affect some 914s. The interference is usually less than 1mm. Very very careful grinding can cure it--just make sure you don't get too close to the brake fluid passages inside the caliper!!!

Another possible solution is moving the mounting points on the trailing arm outward a little bit.

Or you can put your new rotors on a lathe and take a mm off the edge.

--DD

[JmuRiz]

Dave,

I was talking about the thickness of the rotor...not the diameter. Any ideas on this one? Thanks a bunch!

Nathan

[Dave at Pelican Parts]

If the rotor is too thick to fit inside the caliper, you have a vented 911 rear disk and not a 914-6 rear disk. Either that, or something else is really wrong.

Or you haven't pulled the pistons in the caliper back far enough.

--DD

[JmuRiz]

Thanks,
I'm positive they are just the usual 914/6 rotors, as they are not vented at all. I'll make sure that the pistons are ALL the way in. If that still doesn't fix it I'll have to think of something else. Thanks for the quick responses.

Nathan

[Rouser]

I ran into the same two problems after replacing both of the rear 914/6-type rotors on my 5-bolt conversion.

I had 'bout 1-2 MM machined off the diameter of the rotors (Problem #1) and, with new brake pads, you HAVE to fully retract the pistons (Problem #2). Some coaxing is involved with stubborn calipers, and it hard to juggle that while turning the retraction allen bolts in the proper direction (insert "grief" here).

So that you don't add to your frustrations, make sure that the rotor is firmly seated against the hub; some washers and a pair of wheel nuts should seat them properly.

[Bleyseng]

I forgot about that Rouser! Yes, you have to bolt the disc to the hub to get everything to fit as it is tight!
Geoff