Pulled my old water pump on the 78 280Z and I had 4 bolts of various sizes. One was bigger then the other three. The other three were of the same size but of different lengths.

Does this sound right? I'm wondering if I should have had 5 bolts holding in the water pump. Am I missing a bolt or does the 4 of various sizes sound right??

Thanks.

Jeff Woodard

Okay, I think I figured it out. Should indeed be 5 bolts (great, just great). I'm figuring the missing bolt must have broken off when a previous owner worked on the water pump. It wasn't leaking but I replaced it anyway since I had the radiator out. Now, it's leaking.

The bolt in question is the bolt at the bottom of the pump. How impossible is it going to be to get that stud out? I'm already afraid of the answer . . . .

Jeff

Sorry to hear your woes mate :disappoin

The bolt sizes are:

2 short M6 bolts

1 long M6 bolt

2 long M8 bolts

By your description, you've got a broken M8.

Take your water pump off and have a look to see if there is any of the bolt shank left sticking out of the engine block. That will help you to get the bolt out.

Lots of penetrating fluid and let it soak for as long as you can.

A common problem with L's, it's happened to me a few times.

Good luck with it.

Yup, busted M8. And it isn't sticking out.

What's the SOP for getting the sucker out? Penetrating oil and an easy-out?

Jeff

Chase all the holes with a tape and use "anti-seize".You have a long shot(really long)of getting the busted bolt out with a left hand drill bit.But odds are the cover is gonna have to be pulled.

Those bolts that bolt to the block also help to secure the front cover to the front of the engine block (the two M8's and the long M6).

The situation you may be faced with is to remove the front cover off the engine to remove the remaining M8 bolt.

You said it was leaking after you put on the new water pump. At that point, did you have 4 or 3 bolts holding the water pump on?

IMHO, since you've got things apart, I would dive into it and take the cover off to remove the broken bolt. Can you do it now or is it a daily driver etc?

This job isn't massive but it will take several hours to do, depends on your skills, patience and tools.

Look, at this point, I'll suggest you see if anyone else posts their thoughts and suggestions so you can decide which is the best option for you.

Cheers.

When I was resurrecting my Z with almost the same problem, I had to remove the front cover. The bolt had broken off flush with the block.

I used a small diameter welding electrode, Eutectic 680CGS, 1/16" diameter, and built up the end of the bolt to the point where I could weld a nut on it. It was gravy from then, as I just put a wrench on the nut and, voila! out it came.

Using the weld-out technique you eliminate the likelihood of your drill sliding off center and into the block, breaking the EZ-out bit, and so forth. The downside is that you may have difficulty in getting the electrode dead-center on the broken bolt and end up welding to the cast block. Even then, you'll only pull a small patch of cast iron when you get the nut on and bolt out, which is better in my view than a series of drilled holes surrounding the bolt hole. Just my 2 cents.

Frank