View Full Version : water pumps/engine running hot

06-23-2006, 09:57 AM
I have a 1963 studebaker Hawk,I just replaced the water pump last summer. I recently noticed a increase in the temperature gauge,I was told that there was a problem with rust or debris collecting in these water pumps which can cause the engine to run hot is this true? could someone give me some troubleshooting tips.

41 Frank
06-23-2006, 11:08 AM
More then likely you have an issue with the thermostat or the radiator could be partially plugged, the fact that you replaced the pump last summer would pretty much rule it out as the culprit. With a good quality coolant in the system the pump should not have any buildup on it. It is also summer now and engines tend to run warmer.
No way to check radiator except to take it out and have it flow tested at a radiator shop or flush the system yourself with a kit from your auto supply store.

06-23-2006, 03:20 PM
Did you buy a rebuilt original or a repro? If you replaced it with one of the repro pumps, it is possible you may have one of the ones with the looser tolerances that don't move as much water as the originals.

06-23-2006, 04:08 PM
I too have a 63 Hawk & recently had the heads off due to a blown gasket.The water coolant ports in the head & block were heavily calcified & in some cases completly blocked.A good cooling system cleaner should dissolve these deposits if you have any & probably do.
It may also be a good idea to knock out a couple of frost plugs & run a hose through the lower block area.You will be amazed at the crud that builds up over the years & can restrict water flow.Having the rad. checked is a first.I can't see it being the water pump if it's new.Nothing worse the overheating to spoil your fun

06-23-2006, 04:39 PM
Kmul alludes to what might be the real problem. I doubt (and I've never heard of)the water pump clogging up.

You need to use a candy thremometer to check the temp in the radiator when the gage is showing it's overheated. If the thermometer makes a liar out of the gage, there's a fair chance that lots of rust/crud has accumulated at the rear of each cylinder bank's cooling jacket. This causes a hot spot back there - and guess where the temp sender is.[xx(]
The fix (for the crud anyways) is to take out the two threaded block drain plugs and the two, rearmost freeze plugs as well as the thermostat. Then insert a running garden hose into the radiator neck and probe around thru the drain plug and freeze plug holes with screwdrivers or some other sharp device and KEEP digging until the water running out (from the hose) runs fairly clear. It's a dirty, nasty task but your Stude will run better when you're done.;)

Miscreant at large.

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe
1957 President 2-dr
1955 President State
1951 Champion Biz cpe
1963 Daytona project FS

06-23-2006, 05:23 PM
I had a really strange waterpump issue on a GT Hawk we just sold on ebay. It turned out the impeller came off the shaft of a rebuilt pump !

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06-23-2006, 07:46 PM
I've seen that once myself!:( Realized the car was well warmed up and yet there was no visible flow in the radiator tank.[xx(]

Miscreant at large.

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe
1957 President 2-dr
1955 President State
1951 Champion Biz cpe
1963 Daytona project FS

06-23-2006, 07:52 PM
Without pulling the radiator you could look for temperature variations with a laser thermometer. It may or may not pinpoint the problem but they are fun to play with.:D

06-23-2006, 10:59 PM
Judah, many of the water pumps that have been sold in the last couple of years have not been made to the correct tolerances. This has been a problem even dating back to the sixties when Studebaker issued a service letter about the problem. The water pump impeller needs to be pushed onto the shaft so that the tip of the impeller is .934 to .938 inches from the flange of the water pump. Many of the impellers are pushed too far onto the shaft. This results in too much clearance between the impeller wings and the inside of the water pump housing. Too much clearance equals a big drop in the pumps efficiency. One more thing that affects this clearance is the thickness of the gasket you use when installing the pump. It should have only a very thin gasket. If you are experiencing overheating when you had none before changing the water pump, I would take it out and measure it.

Tim K.
'64 R2 GT Hawk

chocolate turkey
06-24-2006, 09:49 AM
Several notes; the temperature of the system can be easily checked with the laser temp checkers. They are readily available and work well. Check the temp at each of the four corners of the radiator. they should be reasonably equal.
We had a local Stude guy with the re-pop water pump issue. Might be worth a look.
Also, when replacing the coolant, use a diesel engine coolant that doesn't have the silicone additive. I've seen two engines clogged with the stuff and restricting the passages to the point of over-heating. That was a puzzler....
As mentioned, clean out the gunk that has accumulated and I'll bet the rear freeze plugs are weak!


Brian K. Curtis

Mike Sal
06-25-2006, 10:37 PM
One way to check to see if your water pump is assembled correctly is to stick a piece of modeling clay onto one of the fins of the impeller and then install the pump with a couple of bolts, but no gasket. Then remove the pump & cut the squished clay with a knife so you can see how thick the clay is on top of the fin.

The ideal running gap is .030 inches. To figure how much your gasket adds to the total gap, measure it's thickness, then subtract 30% (the amount it will squish when installed. The original gaskets were only .015 thick, but most replacements these days are .030.

If the impeller is on too far and the gap is too big, it depends on what kind of pump you have if it can be fixed. If it's a rebuild original, they may have machined too much from the body & had to push the impeller on too far to get the seal to it's proper height. If this is the case, your screwed. The impeller & seal would have to be removed & shimmed.

If you have one of the "new" pumps Which Lionel had tooled up, it will have a one piece seal, which means you can possibly save the pump by taking a small 3 jaw puller & carefully pulling the impeller back the distance you need.

I work for a water pump company & have been around these for a long time. I've seen about every way possible to screw one up. I have the original mahogany wood master (which I saved from the dumpster) for the original pump body casting.
Mike Sal