I bought a Meziere electric water pump and it said it came with new hardware. But sadly, there isn't any in the box. I know the factory bolts are torque to yield, and need to be replaced. But I cant find any replacements for the 3800 engine, only the 3400. Does anyone know the two different sizes of the bolts for the 3800 water pump?

 

Are they actually torque to yield? Never looked in the manual TBH and I've honestly never seen anyone replace them on a 3800. I know the install procedure is torque angle, just had never heard they were TTYs also.

I've got bolt sizes from back when I was planning to replace a bunch of bolts with nicer versions. Take it with a grain of salt of course, and I'd certainly bring your old ones to compare if you didnt chuck them:

Short = 1/4-20 × 1 1/8"
Long = 5/16-18 x 3"

 

Ah, I must have mistaken the torque angle spec to mean TTY. My bad.

I've seen people say the longer bolts are 25 ft lbs plus 80*, but my service manual doesn't say anything about an extra 80*, just the 25 ft lbs for the long bolts, and 16 ft lbs for the shorter ones.

 

Not uncommon honestly. Since the vast majority of TTY bolts are spec'd with torque angle, many people get them interchanged. It is possible (although uncommon) to have a TTY bolt specified with a straight torque value, or to have normal bolts spec'd with a torque angle within their elastic range. The manual should specifically call out bolts that are one time use / TTY though.

Unfortunately I dont have my manuals unpacked yet from the move, otherwise I'd check what I've got too. That kinda stuff drives me nuts though- when you end up with different info for the same thing. I do recall having one manual (maybe it was the cheap Autozone book?) that called out a single spec for 'water pump', even though there are clearly two different sizes of bolts.

 

Alright, I got the Meziere pump installed with new grade 8 bolts. I can confirm that the bolt info you provided is correct. I only torqued the four larger bolts to 25 ft lbs, so I'll definitely check to make sure they don't leak when I fill the system tomorrow. I also wanted to throw in some pictures.

Stock 3800 water pump vs. Meziere HD water pump






I definitely wont have any issues cooling the engine in the Texas heat with this thick of a radiator


Speaking of Texas heat, I had to go out and buy a canopy and box fan to even survive installing this water pump.

 

That is a pretty radiator.