968gene

Went to replace the water pump on the 944 race car this weekend and the PO had broken a stud on the last replacement. Any ideas? We tried heating the surrounding area and turning the nub with Visegrips, no luck. Now I have a very short nub. Thanks in advance for ideas.

josephsc

I've made that mistake by over-torquing.... Have you tried using a 'screw extractor' or a 'Drill-Out'? I've found that using a left-handed drill bit and penatrants like a PB Blaster helps with the extraction.

Good luck.

F18Rep

Ok, just an idea but ...
[careful] grind 2 small flats on the nub and get a good grip, some heat is your friend (but not too much)
or
mount the old water pump, find a drill bit bearing (essentially a spacer) to fit the hole with the broken stud and the bit of your choosing, drill it.

I drilled my freehand and got lucky. Bruce

968gene

Bruce, we thought about using the old pump as a guide, but wondered about losing the core charge. Any ideas on how to source a bit bearing of the correct size? Thanks.

75ohm

I used a set of bolt extractors on a broken block stud... worked great. Spray PB on there and be patient while it works - several times for upwards of an hour.

db944

I, too, have battled the dreaded WP stud. I echo previous advice. Be PATIENT! Lots of PB blaster over several hours. Then apply some heat to the surrouding area. One of the mini torches used for Creme Brulee works great. (tasty, too!) Then get a nice set of vice grips on the flattest spot you can find, and clamp, turn, unclamp. clamp, turn, unclamp. Repeat until she loosens up. Don't Give up!

Yabo

Man, how can you overtorque those things anyway? the one or two i put even stock torque on just stripped out..

F18Rep

"Bruce, we thought about using the old pump as a guide, but wondered about losing the core charge. Any ideas on how to source a bit bearing of the correct size? Thanks."

McMaster Carr... find them on the net...bruce

89magic98

Don't forget the anti-seize on reinstallation.

We had to use a pair of vice grips to get a wp bolt out once. Might work for a stud.

StoogeMoe

It's not over torquing them that makes them hard to get out, it's some kind of ionic process going on. It welds them into the aluminum block. The other tough ones are the two bolts in the head that bolt around the water jacket for the temperature sensor. I had to have mine drilled out by the machine shop for the rebuild.

I used anti-sieze on all bolts / studs around the water areas. Hopefullly this will prevent problems for any future disassembly.

____________________________________
1986 944 NA - Guards Red - 90k miles
1983 944 NA - Platinum metallic - beginning a new life
1985.1 944 NA - Guards Red - donor car
1984 911 Carrera Coupe - Guards Red (gone, but not forgotten)
"If you're not living on the edge, you're not living"

Granite 944

What did you use for your "heating" source? A propane bottle torch, or a map torch will not be able to apply enough heat to do ya any good........anyway.
Acetelyne on the other hand............WILL, butt, ya gotta be a little careful about it also.

Sometimes a couple of tries using heat may result in success, with enough time to let all cool off between times. You are heating the surrounding area of the bolt, and NOT the bolt itself.........right?

You still have enough bolt to grasp? Drill and extractor should be the VERY LAST, LAST resort. To many people have WAY TO MANY PROBLEMS GOING THIS ROUTE. Don't go there, unless you've have had LOTS of experience doing so. Just my .002.

Clean threads (tap and chase nut, wire brush on grinder at LEAST), then anti-seize, and the "proper torque values"..........ARE your best friend on re-assembly.

Tom M'Guinn

I broke a wp stud and failed at all attempts to get it out. I took it to a shop with an EDM set up and figured that would be fool-proof, but the EMD machine actually screwed up the block enough to require welding to repair. If I had to do it again (after vice grips and the like fail), I'd make a jig and just drill for a heli-coil.

jason952

the studs screw out of the block counterclockwise just like the bolts, right?

Tom M'Guinn

Right.