Hi everyone. I’m back again requesting assistance, this time for water pump bolts.

I’m brand new to working on my truck and did a poor job keeping track of where each bolt came from when I removed my old water pump. I think I’ve got it mostly correct but the two bolts that are the second longest seem a bit too long for the spots I have them.

I’ve scoured the Internet, trying to find a helpful diagram, but have not had any luck yet. Is anyone able to assist?

The two I’m point to are the ones that seem to be bottoming out before they snug up to the new pump.







Thank you!!

 

@Rcardot Would the bolts be tight if the AC / PS brackets were in place?
On my 1986 truck a lower passenger side bolt also gets the Alternator adjustment arm.

 

I appreciate the reply.

I do have a bracket that is also caught by the lowest left bolt. That is part of what makes me think that one is in the right spot.

I feel like by a process of elimination, I must have them right. I just don’t want to make a costly mistake.

Bolt placement seems to be a common question but I don’t see many responses that match well with what I’m working with.

thank you!

 

You could use a depth guage to measure the depths. Dry fit a couple bolts through the water pump to hold it in position to measure together or separately and adding them up. My micrometer has a spline tool just for measuring depth.

Next time take a cardboard box and count the number of bolts and then using a screwdriver punch in that many holes in the box. Either in a line noting the position of the first bolt or in a pattern like you drew. Then as the bolts come out pop em in the proper hole you punched in the box. Also a handy way to hold the bolts if you want to paint them.

 

All great ideas.

thank you!!

 

Watch out because the bolts may be a mix of metric and SAE. Some sizes are very close, such as 10mm and 3/8". 10mm is a few whiskers bigger, so it's possible to fit a 3/8" bolt partway until it jams because of the different thread pitch. I do not care to discuss how I learned this... 8mm and 5/16" are very close, too.

This may not be an ironclad rule, but female threads in the block are usually SAE. Female threads in the timing cover can be either type. Several years when I replaced the timing cover, the original one had female SAE threads but the replacement was all metric.

Make sure the female threads are clean. Expect a little coolant to have weeped in there over the years, which sets up some grainy white corrosion. Even if you have the same bolt to reinstall in the same hole, the corrosion may be stopping it from seating fully. I purchased a long tap to clean out the threads in the block without removing the timing cover.

Once you know all female threads are clean, get an extra long bolt for a test fit. Make note of the length. First slip the bolt in without turning, and measure how much is sticking out. This tells you where the top of the female threads start. Now thread the bolt in until it stops and measure the difference. This tells you the length of the engaged threads. IIRC, you want to see at least 1.5 times the bolt's outer diameter for engaged threads. You can also calculate how long the correct bolt should be, with at least an 1/8" margin before it would bottom out.

 

I appreciate the cautionary advice and the additional great ideas.

Thank you!