Kevs435

I blew a hole in the water pump casting on my 1969 Vette 350/350 4 speed last October. I've had the car for 4 years and it's been very reliable. I was turning around 4,500 rpm in third gear and shifted into 4th about the time I smelled coolant. Temp gage went from 180 to 200, so I turned off the car and coasted into a parking lot. Had it towed home and put on a new AC Delco pump last week. Took it out this spring and it tore the gasket on the right side of the pump after less than 10 miles and had it towed. Replaced the gasket and it literally blew the majority of the snout of the water pump off this afternoon. Fortunately, it did not come through the hood. Has anybody seen anything like this. Apparently, there is a lot of pressure in the cooling system. No water in the oil, and it runs cool right up until the point where I blow the water pump apart. No vibration and fan clutch seems fine. Engine was rebuilt many years ago. Runs great until it pukes antifreeze. All 3 incidents were when the car was under a load and turning 4-5,000 rpm. Please help!!!

Shark Racer

Sounds like you might be pressurizing the cooling system - have you ahd a pressure check done? (Typically, this would be indicative of a head gasket leak)

Kevs435

I have not. I didn't see any water in the oil or white smoke. I read about this being common with bad fan clutch or bent fan, but don't feel any vibration. Also read about misaligned or cracked pulleys. The alternator pulley does look like it isn't aligned very well, but it doesn't squeal or throw off the belt. I'm at a loss.

forman

I would check your clutch fan .. Check for play .. Up down side to side ... Also when you took it off to replace the pump there's a weep hole on the back of the clutch fan if you layed it down it would have lost the oil in the clutch that could have led to failure

Mike Ward

Something is horribly out of balance or misaligned. Nothing to do with pressure in the cooling system.

Gale Banks 80'

This is a good one. Since You blew out a water pump gasket once I would think this would be pressure related problem. I'd start with the easy stuff, like running a garden hose and get water to flow in and out of the radiator, then the engine. Then I would go on to the Cracked Head, Block or Gasket etc. For that I would pressurize each cylinder with no coolant in the engine.

Re reading the above You say that You tore a Gasket maybe not blown out. If You were to pressurize the coolant system to the point of blowing something out I doubt the Pump would be the first thing to go, how much pressure can a hose take. What was wrong with the original pump, small hole, like rusted out?

Kevs435

The pump I had on before cracked all the way around and blew a hole out of it. I'm thinking that if it was a pressure issue, it wouldn't destroy a pump either. I think it would blow a hose off or a gasket. I'm leaning to an issue with the fan clutch. I guess it wouldn't hurt to run a pressure check on the cooling system, though. It runs at 180 for hours on the highway, so it's not like it has had any restrictions in the past.

Mike Ward

Excess pressure anywhere in the cooling system is vented by the radiator cap.

Shark Racer

Assuming the cap works, but yes, I agree and also with Gale Banks 80 above. You'd likely loose a hose before you cracked a casting.

It sounds more likely that there's a mechanical issue, something out of alignment or otherwise.

We'll all be very curious to hear what's going on.

71406

This happened to me once years ago. The snout broke off the pump while on the highway. It was a new aftermarket pump. Replaced it with a OE pump and the problem never happened again. I attributed it to cheap imitation parts. What did you install?

REELAV8R

No amount of pressure the cooling system can develop is going to cause that kind of failure.