John D.

Dang it all...!!! OK - I was replacing my rotors last night on my 993 C4 - and in removing the front caliper, the BOTTOM mount bolt stripped out!! (HUH?? Maybe with heat & time, it welded itself into place??)..

Anyone have this happen and might offer a suggestion?? Anyone have a "fix" (aside from JBWeld and/or racers tape?? ). Do the make oversize bolts? Can I run a bolt all the way through and nut it from the rear? Can I run on the track without brakes?

Anyway - please don't tell me I should replace the knuckle the caliper mounts to - it is a C4..!!

Advice, comments and/or condolences sincerely appreciated..!!

John D.

jcoll1

John, I am by no means an expert on repair techniques of this nature but would a system like timesert possibly work? I used it to great success on my 2.7 head stud issues.

I would think that since the bolt is mostly working agianst shear stress that it would be even stronger?

Agian, just my poor attempt to help.

John D.

Hey Jason!

Not a silly idea at all - in fact - I like an insert idea..! I don't know if they make them in that fine a pitch, but I'm googling it now Also, you are right - it's shear strength, and the current bolt is marked 8.8 (it's sitting on my desk )

Jason - thanks again!!

John

AOW162435

John,
I agree with Jason. There was just a thread on the 996 board which then referenced similar issues with Boxter hubs. The Timecert method seemed to work just fine.

Thread


Andreas

Bill Verburg

Time for RS uprights

Mike J

Wow, there is a fair amount of "meat" so it sounds like the previous guy really overtorqued the bolts. Yup, I would go with the inserts as well, they are pretty strong. Will there be enough clearance to get one in?

(Please take some pictures of the procedure if you do it, I would love it on pcarworkshop!)

Cheers,

Mike

chris walrod

+1

If you need a replacement front upright, let me know, I have a few sets taking up space in the garage.

Otherwise, inserting it would be just fine. Just gotta drill it straight.

John D.

Push, shove - down the slippery slope we go... Umm - thanks Bill & Chris!!

OK - I just ordered the inserts (12x1.5) so they'll be here next week.. In the meantime, I've got a 12mm (1.5 thread) bolt which is long enough to attach a nut to the end, so I'll use that until the insert arrives... Also - anyone have the tightening torque values off the top of their head (I thought it was about 60 ft lbs??)?

My sincerest thanks!!!!!

John

chris walrod

Yes, around 60 ft/lbs from memory.

Bill Verburg

from the good book 85Nm, new bolts every time

(63ft-lb)

John D.

Thanks Chris and Bill..!! 63 ft-lbs it is, then.. New Bolts?? Thank goodness Alfie works at a P'Car dealer, so he can take a look for a set (Hi Alfie!! )

Also - will try to take pics - BUT - BEFORE I DO - I have a massive "clean-up" to do.. If you folks saw what my wheel wells look like - I'd be banished from ANY concourse event in the nation.. My excuse? My C4 is my daily driver - and we are finally coming into Spring (mud season for those of us in NH )...

Thanks again!

John

Raptor

John D: As you begin the tortured hell of cleaning the wheel wells, let us know your process. I have a lot of hard-to-reach accumulated crud and was thinking of going to steam cleaning. My concern with steam cleaning is (a) finding somewhere that will pull the wheels once the car is on the lift, (b) whether it will get all the crud off, and (c) whether the steam will harm anything.

John D.

Hey Raptor!

Actually - I'm using a pressure washer (a hand-held small one) at it's lowest setting. I'm keeping it away from any fittings, and it's made a huge difference so far!! After that - I'll let them dry and then tackle the rest by hand (or so I say - I'm no concours weenie, so don't be expecting too much (no Q-tips or toothbrushes in my toolbox )

Anyway - you bet!!!

John

Pan58

Sorry but I cannot agree with using a insert or a differnt bolt size, type in this area ... when it comes to brakes its a dangerous area to be playing around with (I am a Boeing Engineer) when failure could cost life.. I know it probaly spendy but I would recomend replacing the unit ... just my 2 cents

chris walrod

I dont think there is anything to worry about provided the insert is installed correctly.

We use Keenserts, Timecerts and all kinds of inserts on the race car uprights to mount brake calipers with no problems. If anything, it would be stronger as your fastening into steel rather than ally. We pull in excess of three and a half G's on the brakes with a 5/16 stud, no problems. Some of these inserts are burried into mag no less.