Minor water pump leak - The 1947 - Present Chevrolet & GMC Truck Message Board Network

el_fantasma · 03-19-2018, 02:22 PM

So after about two years of driving my 72 truck has started running hot while sitting in traffic. I checked the radiator and added about half gallon of coolant. Looking under the trick I see a very small amount of fluid oozing from where the water pump attaches to the block. I waited 10 minutes and there wasn’t even enough to form a drop.

Does a leak like this happen only when the engine is running or while it sits?

I’m not inclined to pull the water pump if I can just check/fill the radiator every six months. I only drive about 2000 miles a year. Pulling the water pump looks like something above my skill level. If this is a new leak, then that’s something else.

Thanks,
Rob

B. W. · 03-19-2018, 03:31 PM

Make sure the bolts are tight & monitor coolant level regularly. I see coolant leaks there on a regular basis. More common on LS engines than small blocks.

It probably only leaks when running because the system builds pressure. If the leak gets worse when your driving you can loosen the cap to relieve the pressure. Stop-gap measure to get you home.

Obviously, the best thing to do is re-seal the water pump. I don't re-seal them when they leak, I replace the pump. (I don't want the customer back in 6 months with another coolant leak)

hdff · 03-19-2018, 04:54 PM

Changing a water pump is not that hard if you are somewhat mechanically inclined. Loosen the belts, unhook hoses from pump, remove the pulley on front of the water pump(4 bolts) and remove the 4 bolts holding the pump on. Install in reverse order , add antifreeze and water. Done ✅

**Steeveedee** · 03-19-2018, 06:10 PM

Look at the bottom of the water pump with a mirror and see if there is coolant leaking from the weep hole there. If so, just change the water pump, if it is. Now, a question- how many miles on the engine? If it's a lot, you may opt for a timing chain and gears, since you are already half way there. When I worked as a mechanic I would make a recommendation, base on the wear that I saw, overall. Nothing like popping the timing cover and finding a chain and gears near failure. Saves the customer money and makes me look good.

toolboxchev · 03-19-2018, 11:27 PM

As time progresses the bolts can work loose and may rust in their perspective threaded spots.

Clean and re tap bolt together with a high quality thread sealant.

jmader · 03-20-2018, 06:53 AM

A minor water pump leak cost me a set of aluminum vortec heads once....

**Grumpy old man** · 03-20-2018, 07:38 AM

Fix it and forget about it before it leaves you on the side of the road ,Why baby it along when you already know it's time to replace it ? It's like saying "my legs only a little broke I'll wait and see if it gets better, I like using these crutches " ??

B. W. · 03-20-2018, 11:08 AM

Quote:

Originally Posted by Grumpy old man

"my legs only a little broke I'll wait and see if it gets better" ??

Crack me up!

harpo231 · 03-20-2018, 11:44 AM

That little drip is your trucks way of telling you "change the water pump before I leave ya stranded" !

03-19-2018, 02:22 PM	#1
el_fantasma Registered User Join Date: Oct 2016 Location: Redwood City CA Posts: 566	Minor water pump leak So after about two years of driving my 72 truck has started running hot while sitting in traffic. I checked the radiator and added about half gallon of coolant. Looking under the trick I see a very small amount of fluid oozing from where the water pump attaches to the block. I waited 10 minutes and there wasn’t even enough to form a drop. Does a leak like this happen only when the engine is running or while it sits? I’m not inclined to pull the water pump if I can just check/fill the radiator every six months. I only drive about 2000 miles a year. Pulling the water pump looks like something above my skill level. If this is a new leak, then that’s something else. Thanks, Rob __________________ 72 White Cheyenne, The Ghost

03-19-2018, 03:31 PM	#2
B. W. Registered User Join Date: Nov 2014 Location: Bigfork, Montana Posts: 1,137	Re: Minor water pump leak Make sure the bolts are tight & monitor coolant level regularly. I see coolant leaks there on a regular basis. More common on LS engines than small blocks. It probably only leaks when running because the system builds pressure. If the leak gets worse when your driving you can loosen the cap to relieve the pressure. Stop-gap measure to get you home. Obviously, the best thing to do is re-seal the water pump. I don't re-seal them when they leak, I replace the pump. (I don't want the customer back in 6 months with another coolant leak)

03-19-2018, 04:54 PM	#3
hdff Registered User Join Date: Apr 2007 Location: pasadena,TEXAS Posts: 880	Re: Minor water pump leak Changing a water pump is not that hard if you are somewhat mechanically inclined. Loosen the belts, unhook hoses from pump, remove the pulley on front of the water pump(4 bolts) and remove the 4 bolts holding the pump on. Install in reverse order , add antifreeze and water. Done ✅ __________________ 1971 Cheyenne SWB 402BB, 700R4, 3.73 posi, PS, PB, A/C, Tilt, Tach "Wanda" Don't argue with idiots, People watching may not be able to tell the difference... There's someone in my head........But it's not me...... cheap tricks thread great info here!! http://67-72chevytrucks.com/vboard/s...d.php?t=489394

03-19-2018, 06:10 PM	#4
Steeveedee Who Changed This? Join Date: Jan 2013 Location: Simi Valley, CA Posts: 10,676	Re: Minor water pump leak Look at the bottom of the water pump with a mirror and see if there is coolant leaking from the weep hole there. If so, just change the water pump, if it is. Now, a question- how many miles on the engine? If it's a lot, you may opt for a timing chain and gears, since you are already half way there. When I worked as a mechanic I would make a recommendation, base on the wear that I saw, overall. Nothing like popping the timing cover and finding a chain and gears near failure. Saves the customer money and makes me look good. __________________ ~Steven '70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper Simi Valley, CA

03-19-2018, 11:27 PM	#5
toolboxchev Registered User Join Date: Jul 2015 Location: 2nd left past the stump on a dirt road. Posts: 2,629	Re: Minor water pump leak As time progresses the bolts can work loose and may rust in their perspective threaded spots. Clean and re tap bolt together with a high quality thread sealant.

03-20-2018, 06:53 AM	#6
jmader Registered User Join Date: Aug 2013 Location: Grand Island, NE Posts: 1,483	Re: Minor water pump leak A minor water pump leak cost me a set of aluminum vortec heads once.... __________________ 1949 Chevy 3100 Five Window 1964 Chevy C10 Lambrecht Auction project 1967 Chevy SWB K10 1967 GMC K15 Project Build thread- http://67-72chevytrucks.com/vboard/s...72#post6502772 1968 Chevy Anniversary K10 1991 K5 4" Lift 35's (the wife's toy)

03-20-2018, 07:38 AM	#7
Grumpy old man Senior Member Join Date: Dec 2013 Location: Gods country East,Tn Posts: 8,545	Re: Minor water pump leak Fix it and forget about it before it leaves you on the side of the road ,Why baby it along when you already know it's time to replace it ? It's like saying "my legs only a little broke I'll wait and see if it gets better, I like using these crutches " ??

03-20-2018, 11:44 AM	#9
harpo231 Registered User Join Date: Nov 2014 Location: Lincoln City DE Posts: 1,292	Re: Minor water pump leak That little drip is your trucks way of telling you "change the water pump before I leave ya stranded" ! __________________ Stan 67 swb BLU MULE posted via flip-fone



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