Water Pump Thread Repair Drill Jig

[Tom]

Here is a fixture you can print to help drill out broken water pump fasteners on the Porsche 944. The plastic fixture relies on metal drill bushings from McMaster-Carr (item number 8492A141; 7/16" OD, 1/4" ID, 3/4" high). You can insert 3 or 4 bushings in various holes to line up the fixture using the block's remaining studs and threaded holes, and put one bushing in the hole where you need to drill. Use a 1/4" cobalt drill bit with these bushings, then tap with an M6 helicoil tap. Mark your bit so as not to drill deeper than needed for the helicoil you are using. Helicoils come in various lengths. 6mm long is safest, although a 9mm long helicoil will fit.

944 Water Pump Drill Jig by Carpokes.stl

jig-on-motor.jpg

[paulgo]

Ingenious - great work. I'm sure this will come in handy.

[Zirconocene]

I sort of assume there's no way this will work on the 3L cars, right? I mean, this exact part. The idea is brilliant!

[Tom]

I sort of assume there's no way this will work on the 3L cars, right? I mean, this exact part. The idea is brilliant!

Thanks, and welcome to Carpokes! Tell your friends. I've actually been 3D printing drill fixtures for quite a while for other stuff, and have been meaning to make this one forever.

Someone had asked about doing one for a 928 but I haven't heard back. If you are also a 928 owner and are interested, I'd be happy to work it up. I'd love to get more 928 owners over here on carpokes.

As for using this exact part on a 3 liter block, I happen to have one waiting to get built, so just put this jig on it and it fits like a glove. I think it's good to go.

jigon3L.jpg

[Tom]

For people with smaller printers and to help combat warping, I broke the fixture into two pieces. A left half and a right half. You don't need both, just the one with the hole you need to repair.

wpjigright.stl

WPJIGLEFT.stl

[Zirconocene]

As it turns out, I am also interested in 928 bits. I've blocked out which car it was on but I had to do a TimeSert repair to the block on one of my cars and it was traumatizing. These jigs would have made things a lot less stressful!

Cheers

[Z28DZ]

A printer is alien to me, but I have plenty of old pump cores. Is there a downside to installing the drill bushings in one and using it for a jig?

[JamesM]

Making my first post to get access to the stl file

[mooreboost]

[DMRK]

Thanks again Tom, another great tool! I could have used this last month when I had a bolt snap. Wish I saw this sooner. After unsuccessfully trying to extract it by welding a nut on I ended up using the old water pump as my drill jig.