Removing plug from water pump

[Ray C.]

I got lucky and purchased a rebuilt GM 3782609 water pump from an auto parts store. The top hole that excepts the aluminum 90* fitting has a Allen head plug in it. I can not get this fitting out. I cut the end of an Allen wrench and adapted it to a 1/2" breaker bar with no luck. I also tried and impact wrench clockwise and then counter clock wise with no luck. Does anyone have any process for removing this plug?

Thanks for any help!
Ray

[Edward J.]

Re: Removing plug from water pump

Ray,
Sometimes They Use A Sealant On The Threads That May Harden Over Time, The Best Way Is Maybe Try A Propane Torch To Heat The Pump To Soften The Sealant, If That Does Work You'll Need A Gas Torch To Heat To Higher Temp

[Clem Z.]

Re: Removing plug from water pump

try the candle wax trick i posted several days ago. you will have to replace the back plate gasket unless you can get the plate off without screwing up the gasket before using the heat

[Ken A.]

Re: Removing plug from water pump

The simplest way is to grind off the plug flush, Then drill it and tap it. Heat will ruin the gaket and front seal.

[Chuck R.]

Re: Removing plug from water pump

In my boiler man days, I would drill out the center of the plug so that I could stick a hack saw blade into the hole and then very carefully cut outward until I was just shy of nicking the threads.

Usually, it took two cuts spaced apart about a quarter of an inch minimum.

Then I would take a very sharp chisel and cave in the plug into itself.

The cuts allowed the threads of the plug and the unit the plug was threaded into to release from each other just enough to break the grip.

Sometimes, one cut would do the trick.

Of course metal shavings will be created so what I used to do was carefully drill out the center as described above and then stuff cotton into the cavity to stop the debris. Then when the plug is removed, I would use a shop vac and suck out the cotton along with the shavings.

No heat required.

Chuck

[Jack C.]

Re: Removing plug from water pump

Ray, are you still calling yourself lucky?

[Ray C.]

Re: Removing plug from water pump

Thanks for the responses! I am sure I will get the plug out, it is not the first problem I have had while restoring Corvettes.
Jack, $19.00 for a rebuilt "609" pump, I still think I am very lucky, unless I destroy it getting the plug out. I have seen "609" cores on EBay go for hundreds of dollars.

Ray

[Randy R.]

Re: Removing plug from water pump

I have better luck heating the plug than the casting.

Randy

[Chuck R.]

Re: Removing plug from water pump

Thanks for the responses! I am sure I will get the plug out, it is not the first problem I have had while restoring Corvettes.
Jack, $19.00 for a rebuilt "609" pump, I still think I am very lucky, unless I destroy it getting the plug out. I have seen "609" cores on EBay go for hundreds of dollars.

Ray

Hey Ray, send it over and I'll get it out for you, no sweat, no charge, just shipping.

Chuck

[Ray C.]

Re: Removing plug from water pump

The plug is out! Built a fixture to hold it true and plumb. Then drilled it out using a drill press and gradually increasing drill size. Finally used a small narrow chisel to crack the plug. No damage to the threads. I learned a little trick today, grease the drill bit and it helps to prevent the drilled metal from going into the pump, it sticks to the drill bit.

Again, thanks for all the advise! Chuck, I will take you up on your offer for free help on my next major problem. (I will be tackling the FI unit next)

Ray

[Page C.]

Re: Removing plug from water pump

I have used the same method that Chuck uses with great results for years. This method also works well on intake manifolds with frozen heater hose nipples. Once you collapse the fitting you can screw it out by hand.
Regards,
Page Campbell

[Chuck R.]

Re: Removing plug from water pump

The plug is out! Built a fixture to hold it true and plumb. Then drilled it out using a drill press and gradually increasing drill size. Finally used a small narrow chisel to crack the plug. No damage to the threads. I learned a little trick today, grease the drill bit and it helps to prevent the drilled metal from going into the pump, it sticks to the drill bit.

Again, thanks for all the advise! Chuck, I will take you up on your offer for free help on my next major problem. (I will be tackling the FI unit next)

Ray

Give me a month or two to bone up on em before you mail it out.
Isn't it similar to 20hp Craftsman tractor carb ?