Anyone ran into this issue before? The bolt seem to be rusted/fused onto the water pump housing. Any suggestion?

 

Welcome to the group!

Unfortunately you're gonna have not-fun fixing that. The whole water pump housing needs to come off. Heat and PB Blaster is your friend.

Also to note - the oil metering lines and wiring runs under the water pump housing and is held there with a little clip.

Dale

 

In add'n to what Dale said, hitting the bolt on the end with a large hammer & punch will help loosen things like that. The impact(s) will often break the corrosion loose while yielding the threads slightly allowing it to be removed.

 

I encountered this. It took a long time to fix. I used a few left-handed drill bits, tapered extractor, and M8x1.25 tap to clean up the threads. New bolt was available at the time from Mazda (via Ray Crowe, he's great). Replacement studs for the water pump were not available when I searched, so take good care of the original ones when wrenching. More details here: https://www.rx7club.com/3rd-generati...-bolt-1150349/

 

Reinstall stud with anti-seize.

 

Along with what others have said. You "May" get lucky if you snap some vice grips on the bolt and Hit the end with a hammer while holding pressure to unscrew it. But soak with PB Blaster first.

 

adding to what has already been said... after you get the water pump housing off you will want to use a stud removal socket. the key here is GRIP. the stud removal socket will grab a large portion of whats left of the stud and give you a better chance at extraction. take your time, use heat, slow rocking motions, penetrating oil. you can put the socket on it at the very base of the stud where it goes into the block for maximum torque application so you dont have to worry as much with it snapping off in a different location.

after you get it out, chase the threads (m8x1.25) and buy another bolt. i believe its a 120mm. install it with high temp copper anti seize. it would be worth doing this to the other studs as well as preventative maintenance.

 

Not on this particular issue, but I’ve had good luck with an induction coil to heat broken studs. Not something that everyone has in a tool box, but they’re not all that expensive. Mines paid for itself a few times over on different things.

 

Thanks for the advices. I'll try the hammer and heat method first and see how that goes!

 

I have a stud extractor, I'll try it after heating it up