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I have a '02 Camaro Z28. I'm in the middle of a water pump replacement and I wanted to confirm that the water pump bolts do not go through the coolant passage and do not require any thread sealant. I'm using a new AC Delco 252-846 water pump and the newer LS2 style thermostat housing ACDelco 15-11057.
I searched the gen III engine forums and I found conflicting information saying the water pump bolts were blind holes that don't contact any coolant, as well as people saying they were actually in contact with the coolant and you should use a thread sealant. (examples of both provided very at end of post)
I'm assuming that they really don't contact the coolant and don't need any sealant, but I wasn't positive and figured i'd ask. I already cleaned up the bolts and plan on cleaning up the bolt holes in the engine with an m8x1.25 thread restorer, and then not putting any sealant or compound on the bolts or metal gaskets unless someone can enlighten me and tell me what type of compound should be put on the water pump bolts. I will be using a torque wrench and torquing bolts to 11 ft lbs on first pass and 22 ft lbs on second pass. I can't find anything in ALLDATA or GM Techline ESI about the water pump bolts needing sealant. Only instructions to install and torque down the water pump bolts, followed right after by a warning along the lines of "Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener."
Anyone who can offer any advice or insight on this is most appreciated. I'm assuming whoever had the car before me just put some kind of junk on the water pump bolts because they didn't know any better, but I rather ask now and know for sure, then assume and find out I was wrong later. You know what they same about assuming...
The main reason I even question needing something on the bolts at all is when taking my old water pump off the bolts had nasty somewhat dried out slightly gooey junk on the bolts/threads.
Water Pump bolts before cleaning
Water Pump bolts after wire brush, thread chaser and parts cleaner.
No example:
Originally Posted by WhiteRhino
Neither need to be sealed. If the water pump bolts have sealer on them. Someone had it apart and didn't know better...The bolts do not go into any passages.
Yes example:
Originally Posted by Paul Bell
...
Now, about the bolts. They do pass into a coolant passage and are exposed to coolant.
You want a SEALANT on the threads, nothing with any type of a lubricant including, moly, anti-seize or Teflon in paste or tape form.
The same Permatex High Tack is amazing on threads exposed to coolant, it'll still be on the threads after 100,000 miles.
Oh if the sealant is on bolts from the factory then yes it seems like it should be used. Do you know what kind of sealant it was or what the equivalent sealant would be? Thanks!
Look, with a mirror and a flashlight or use some compressed air with an air chuck and blow air into the holes, you'll know if they're blind or need sealant. A bright light will show you the bottom of the holes
My water pump bolts also looked like rusted trash, the build up you see, at least on mine was coolant and rust from a leaky gasket.
I recommend the thread sealant to keep the water pump bolts from rusting and seizing in the block, prevent a small leak and water from getting into the threads.
You can use Teflon tape or just regular thread sealant
Thanks for the advice everyone. I appreciate it!
I ended up confirming all the holes were blind holes with a skinny plastic drinking straw
Got all the bolt holes cleaned up and installed the new water pump. so hopefully anyone else who searches and finds this thread, at least in my 02 Camaro all the holes are blind and don't come into contact with coolant jackets, but if you really feel the need to add something to the threads so they are less likely to seize up then be sure to take into account that change in torque this will cause for the fasteners and see the italicised warning in my original post about adding lubricants to fasteners that don't call for it.
Also all 6 water pump bolts were M8x1.25 if you plan on running a thread restorer over the bolts or in the bolt holes to clean them up.
Last edited by HypervisorX; 07-11-2017 at 06:30 AM.
Reason: clarity and warning about torque
Thanks for the advice everyone. I appreciate it!
I ended up confirming all the holes were blind holes with a skinny plastic drinking straw
Got all the bolt holes cleaned up and installed the new water pump. so hopefully anyone else who searches and finds this thread, at least in my 02 Camaro all the holes are blind and don't come into contact with coolant jackets, but if you want to add something to the threads so they are less likely to seize up then go for it! Also all 6 water pump bolts were M8x1.25 if you plan on running a thread restorer over the bolts or in the bolt holes to clean them up.
If you go back to your first post, adding any sealant or other material even though it is not needed will lower the required fastener torque value that should be used. Not doing so can damage the bolts or worse the aluminum threads in the block. New value needs to be computed based on the lubrication. Bottom line, they should be dry when installed per the service manual and there is a reason for them being dry.
Yes thank you for pointing that out vettenuts. I did install mine dry, and i have updated the post you quoted to be more clear about the fact that adding something to the bolts that wasn't called for will cause the torque values to be different and is not recommended.
If you go back to your first post, adding any sealant or other material even though it is not needed will lower the required fastener torque value that should be used. Not doing so can damage the bolts or worse the aluminum threads in the block. New value needs to be computed based on the lubrication. Bottom line, they should be dry when installed per the service manual and there is a reason for them being dry.
You are putting WAY too much thought into a water pump bolt. Choke up on the ratchet and snug 'em up.
Worked on structural dynamics including shock and vibration of bolted joints for 40 years, guess I do tend to be precise in my methods.
It's the people that think that precision is a waste of time that can never seem to get things right, or do things like torque rod bolts without a torque wrench or tq angle gauge, and then become baffled at why their **** is a pile of ****.
That wasn't a shot at the muthugga I think was the screen name? I understand him saying that about the water pump bolt, it truly is a simple creature where precision or meh will work fine lol.
Last edited by 00pooterSS; 07-12-2017 at 05:46 PM.
After shearing a rusted water pump bolt on my 6.0 block in the pickup truck I now use anti seize on the water pump bolts. No fun getting one of those out of the engine block.
07-08-2017, 08:44 AM
Water Pump Bolt thread sealant, yes/no? 
(examples of both provided very at end of post)
