The Valley of broken bolts...my story of water pump replacement

[DMCMW Dave]

I've had the most luck combining heat with penetrating oil. ........ That was the only way I could get my exhaust crossover pipe free.

I've never had penetrating oil help at all in aluminum/steel bonds. There is no aluminum involved in crossover pipe joints.

The absolute worst is putting (dry) stainless fasteners into aluminum. You may as well weld your engine together.

[mluder]

I've never had penetrating oil help at all in aluminum/steel bonds. There is no aluminum involved in crossover pipe joints.

The absolute worst is putting (dry) stainless fasteners into aluminum. You may as well weld your engine together.

All true... I was thinking more technique rather than direct correlation. Still, you have way more experience than I do and I've been fortunate to have broken only one bolt. It was an exhaust manifold to engine so that was a steel on aluminum connection. I was able to get it out by drilling the center with a left hand thread bit and a bolt extractor. Again, I count myself extremely fortunate.

[David T]

All true... I was thinking more technique rather than direct correlation. Still, you have way more experience than I do and I've been fortunate to have broken only one bolt. It was an exhaust manifold to engine so that was a steel on aluminum connection. I was able to get it out by drilling the center with a left hand thread bit and a bolt extractor. Again, I count myself extremely fortunate.

Heat works the best with the exhaust hardware and especially steel on steel. It can't work if you break the bolts first before using heat. Be sure to use Never Seize when reassembling things. The nest person to take things apart again my be YOU! Learning how to use an Oxy-Acetalyne torch is a very handy skill. The equipment is not expensive and the skills are not difficult to learn, all it takes is practice. With it you can heat, heat treat, weld, braze, solder, and cut.

[BigBenb84]

Would there be any thing against going from M7 to an M8 sized hole? I understand don't go deeper, but 1 mm larger? M8 is much more common then M7 and I might have to go that big to get out what is still in the holes.

[Bitsyncmaster]

Would there be any thing against going from M7 to an M8 sized hole? I understand don't go deeper, but 1 mm larger? M8 is much more common then M7 and I might have to go that big to get out what is still in the holes.

I've done that in many places. It all depends on how much stock is around the hole.

[DMCVegas]

Ok, just throwing this question out here: Could leaving this car connected up to a battery tender have resulted in electrolysis that welded the bolts to the block?

I replaced my water pump twice (first one was defective) and had to fix a leaking O-Ring on the Y-Pipe and didn't have any problems at all with removing any of the bolts. Save for a single By-pass Flange on the Driver's side which was actually my fault for not chasing the threads upon reinsertion where I over-torqued it and snapped the head off. My car as an example was never maintained, just dumped on the side of a house after the owner died. So once the battery discharged, the car sat with 0 power for years.

[burch]

Would there be any thing against going from M7 to an M8 sized hole? I understand don't go deeper, but 1 mm larger? M8 is much more common then M7 and I might have to go that big to get out what is still in the holes.

Sorry to dredge up an old thread, but did you end up doing this? I had zero problems getting the manifold bolts out, however, I discovered the left rear (back of car) hole is stripped. Debating larger tap or going the helicoil route.

[BigBenb84]

I did go bigger. Everything is fine with it. I've put thousands of problem free miles on since doing this job.

[David T]

I did go bigger. Everything is fine with it. I've put thousands of problem free miles on since doing this job.

If you do find you have to go bigger the thing to do is to put the bolt in and then cut it flush. Now redrill and tap to the correct size. Best to try to keep all of the fasteners the correct size but if you have enough room it can't hurt to go bigger. It just becomes a pain if you have to work on it again, different size wrenches, keeping track of which bolt goes into which hole, enlarging clearance holes in parts, etc.

[vps3922]

You may as well weld your engine together.

lol! Awesome. That expression made my day!