Water Pump on 76 C10 350

[HBlue]

I assume the water pump on this truck is original because it is painted orange and the truck only has 51,000 miles. The first pump I got from the parts store had a threaded bolt hole for the PS bracket, but the original is not threaded.

On the next one they had, the PS bracket bolt hole was not threaded, but the alternator bracket hole was located about an inch further toward the front. This means a different water pump or a different alternator bracket.

They got off the computer and into an old stack of reference books and finally decided the 76 water pump was different. They should have another one Friday or Saturday.

Anyone else have this problem?

[ray_mcavoy]

I know the alternator brackets were changed slightly in 75 but I didn't think that made a difference with the water pump (it might though).

The change from the un-threaded to the threaded hole for the PS pump bracket took place in 77 ... that definitely makes a difference in the pumps.

[Gregski]

Originally Posted by HBlue

I assume the water pump on this truck is original because it is painted orange and the truck only has 51,000 miles.

I doubt it, most likely your odometer has spun over at least once, more likely twice, and it's highly unlikely the original water pump has lived that long. Water is the biggest enemy of the Internal Combustion Engine, it is unforgiving, and the water pump is one of the first accessories to go.

[HBlue]

Ray
Thanks for the timing in the changes. My 78 Silvarado has the same alternator bracket as the 76 C10 and the same spacing on the water pump, but I've not checked the PS hole.

Gregski
As for the 51,000 miles, the 76 C10 sat under the same carport since new. I bought it from the son of the original purchaser. It only had 800 miles on it since the last oil change 3 years ago. The interior was all original. I changed the dash lens, which had become milky, and replaced the door pannels and arm rests, which had faded.

[bnoon]

I got an unthreaded water pump to work on my '74. I had to get a nut on the back side of the bolt. Took a couple of tries, but I finally got it on there. Pain in the butt.

[HBlue]

The third water pump worked fine.

I didn't need it, but this one came with a spacer and bolt for use on the wider style alternator bracket.