Click on image for the lowdown. 
====
| | | Forums66 Topics128,015 Posts1,055,335 Members48,419 | | Most Online14,466
Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
| | THANKS!
For helping keep this great
old truck web site
on the Internet for over 30 years! and not clogged down
with Ads!  Again, thanks!
| | | | Joined: Sep 2014 Posts: 120 'Bolter | | 'Bolter Joined: Sep 2014 Posts: 120 | Getting ready to install a new waterpump on a '54 235 engine.
I noticed three holes in the back of the pump and three holes in the
block... not counting the bolt holes.
The smaller 3rd hole in the block just above the inlet and outlet holes in the block goes nowhere. There is a matching hole on the back of the pump.
Why the hole if it goes nowhere into the block. ?? And, why would the pump have this corresponding hole?
Jerry
1 1951 Chev Panel with a 350 small block, automatic tranny.
1 2004 Chev 2500 HD pickup... stock
1 1950 Chev 5 window pickup; 261 c.i. engine, 4 on the floor.
With lots of time and money, any Stovebolt can be restored.
| | | | | Joined: Jan 2001 Posts: 5,337 'Bolter | | 'Bolter Joined: Jan 2001 Posts: 5,337 | The third bypass hole goes only a little way into the block, but then turns upwards through the head. This allows a small amount of water to circulate to the pump through the engine while the thermostat is closed.
See the USA in your vintage Chevrolet! My Blog | | | | | Joined: Sep 2014 Posts: 120 'Bolter | | 'Bolter Joined: Sep 2014 Posts: 120 | Dave:
The bypass hole was completely filled with rusty crud. I hand turned a drill
bit in the hole looking for a water exit. Found none.
What am I looking for? A pin hole or? Should the bypass hole be completely
drilled through the block?
Jerry
1 1951 Chev Panel with a 350 small block, automatic tranny.
1 2004 Chev 2500 HD pickup... stock
1 1950 Chev 5 window pickup; 261 c.i. engine, 4 on the floor.
With lots of time and money, any Stovebolt can be restored.
| | | | | Joined: Jul 2014 Posts: 1,289 Moderator for Tons o' Fun , Co-Moderator Driveline Forum | | Moderator for Tons o' Fun , Co-Moderator Driveline Forum Joined: Jul 2014 Posts: 1,289 | The passage for the coolant is not "straight through" , its turns up into the head. Try bending a piece of wire or coat hanger so you can probe the opening. I don't have mine apart, but a flashlight and a mirror may allow you to see it.
Ron - - Dusty53 1954 Chevy 3604In the Gallery Forum "You can't dance with the Devil and then wonder why you're still in Hell."
"They will forget what you've said, and they will forget what you have done but they will never forget the way you made them feel." | | | | | Joined: Sep 2014 Posts: 120 'Bolter | | 'Bolter Joined: Sep 2014 Posts: 120 | Thanks, I'll probe for the opening at the top side of the hole.
Findings to follow...........
JB
1 1951 Chev Panel with a 350 small block, automatic tranny.
1 2004 Chev 2500 HD pickup... stock
1 1950 Chev 5 window pickup; 261 c.i. engine, 4 on the floor.
With lots of time and money, any Stovebolt can be restored.
| | | | | Joined: Sep 2014 Posts: 120 'Bolter | | 'Bolter Joined: Sep 2014 Posts: 120 | Yep, found the hole after some digging. Lots of mineral deposits, rust and crud.
Who knew? Thanks Dusty 53 and Dave for the help.
Jerry
1 1951 Chev Panel with a 350 small block, automatic tranny.
1 2004 Chev 2500 HD pickup... stock
1 1950 Chev 5 window pickup; 261 c.i. engine, 4 on the floor.
With lots of time and money, any Stovebolt can be restored.
| | | | | Joined: May 2001 Posts: 7,438 Extreme Gabster | | Extreme Gabster Joined: May 2001 Posts: 7,438 | While you're at it, remove the drain plug at the left rear of the block and run your wire around in there while running water through the block. | | | | | Joined: Sep 2014 Posts: 120 'Bolter | | 'Bolter Joined: Sep 2014 Posts: 120 | Will do cletis......thanks for the tip.
JB
1 1951 Chev Panel with a 350 small block, automatic tranny.
1 2004 Chev 2500 HD pickup... stock
1 1950 Chev 5 window pickup; 261 c.i. engine, 4 on the floor.
With lots of time and money, any Stovebolt can be restored.
| | |
|
|
