Coolant leak at water pump

TXD · May 12, 2012

Got a '01 2500hd 6.0L 4X4 CC

Slow coolant leak over the past month. But now I had to fill it 2X this week. Looking at the front of the engine, slightly right of center, looks like its dripping at the bottom of the pump. Can't see too good in the pic here but am I judging correctly that I need new pump + gasket ?

txab · May 12, 2012

Yep.

gmtech4 · May 12, 2012

you need a light and a mechanics mirror to see where its comin from then go get a water pump,,gaskets come with,,my advise is to go with a factory water pump,

after market everything sucks imo

TXD · May 15, 2012

Screwing up an anvil was something my dad said I could do regularly when I was growing up.

got started bout 4:30. Well, 1hr. later, pumps off so far so good. Momma gets home about 6:00, I order pizza for us and head out to pick up new pump and pizza. Mount new pump, install thermostat housing and shear off a bolt! Take thermostat and pump back off. Can't find a bit I thought I had for this! Can't grab with vise-grips! Weld a washer to the bolt that doesn't quite fit the bolt. Weld a nut to that. Well, tried too soon and/or bad weld twisted right off! Try again with new washer and nut. Call a few folks and locate a back-out bits kit. Well my welds worked, got it out. Back to oriellys to get new bolt. Mount it all back up and then make 1gal. of 50/50 mix and then 1gal. of my drainage I have to filter to clean it. Start to pour in but it leaks out!! I pinched the O-ring for thermostat!!! back to oriellys. Get new O-ring in, pour coolant......success!!! Run truck while I clean up and gotta add a bit more coolant now that it's cycled through. 11pm finally done!!

txab · May 15, 2012

Nichevo · June 14, 2012

Newbie alert...Got a question. Need a new water pump - at least the garage says so, I guess it could be a gasket but by the time I tear down my daily driver I don't want to be left with nothing but my crank in my hand - for the LM7 5.3 in my 01 Suburban. I think I can do it myself. Now this was inherited from a friend, it has 222K miles, just about all the original parts AFAIK, so on the one hand I want to treat her right, on the other hand there are a lot of choices for a pump.

I can buy new from pretty good ebay vendors (or rockauto for a little more) the $120 ACDelco 251-743 OE Service Part, or the $80 252-845, which is the Professional line part and is probably made in China. Then i have to get a new inlet/thermostat for maybe $30 from ACDelco, plus some kind of new bolt apparently - can't reuse the old?

Meanwhile if I paid $80 for a Chinese part, is that better, equal to, or not as good a a Gates, GMB, Napa no-name ("probably China" the busy parts counter guy said) new pump? A Cardone? Rockauto offers four Cardones, 2 new and 2 reman. The Cardons start at $50.

Or, I can get a salvage part off ebay or out of a yard. One guy is offering a "

GM Truck Water Pump 4.8 5.3 6.0 LM7 L59 L33 LQ4 LQ9"

with the bidding (Item number: 261042666386) starting at $3 + $20 S&H. That's more my thinking. There are other used pumps under $50 shipped.

Now, if the pump fails, it isn't a detonator to a bomb. I guess the truck will inevitably overheat, but the engine won't immediately melt, the car won't explode killing everyone inside, I just gotta pull over, limp home and redo the pump. Yes?

So i am thinking to gamble on a salvage part, new gaskets, and whatever new rubber (belts hoses pulleys) seems wise - new stat or not depending on my mood - the pump I mentioned includes the inlet and stat.

2 main questions:

1) Fitment. Will any 5.3 pump from 00-06 fit my motor? I know that for the 04 onwards they changed the inlet to the smaller size, i get that. But does anything else change? In other words, if I buy a OE pump off an 06 Silverado L33 motor, for instance, with 60K miles, with inlet included, will it fit my 01 LM7, do I need anything but new Fel-Pros? Does this sound like a reasonable gamble? I don't need any other tools but whatever it takes to get the fan clutch off, and I probably have a big crescent that will do.

2) What other parts should I replace at this time? Now I think the last owner did nothing he didn't absolutely have to (he's gone, I can't ask him). So aside from the fluids which may be a time bomb and I am working on getting that all done, I'm sure he never did the belts, let alone tensioners, idlers, hoses. Are any of these bombs/instant death to the motor? Or will symptoms develop and I can fix them when they fail? What happens when say a belt goes? Instant motor death? I've had work done on the motor and nobody ever said to me, "Boy, you get new rubber on that mofo or you'll be sorry." I remember the line "do the belts every seven years no matter how they look" and I can spend that money, but how far does that go? What do I check?

Also,

3) Whether on my old pump or on the used one I buy...what do I inspect on the pump? Do I pry off the circle on the back, look at the impeller, get the repair gasket, RTV it, slap it back on? Do I need special tools for this? What kind of RTV? How do I check the bearing? How do I check all the parts?

and now that I mention it...

4) Some come with the two Fel-Pros (or heavy paper gaskets). Some also have the thin O-ring to seal the stat/inlet. Ok...but this one also has a fourth gasket (ebay Item number: 120676321322) about the O-ring size with two bolt holes. If I don't get that seal in a kit, does that mean I don't need it?

Your help is much appreciated in advance. She's beginning to howl a little under the hood...funny noise if you don't know what it might mean.

txab · June 14, 2012

Or the pump fails and leaves you stranded in the middle of nowhere. Don't buy a used pump. Buy a quality pump. Any of the name brands should do you well. If there is a problem you have warranty, which with ebay or used POS from the junkyard you have none

Silverado4x4 · June 14, 2012

Dont cheap out and buy a used pump or other, stick with OEM a little more money but worth it. I have seen cheap pumps go out lock up the shaft and send the fan into the radiator and destroy the radiator.

gmtech4 · June 15, 2012

did he say "salvage"?????????

OMG ,my head is about to explode .....

must resist the urge to freak out,!!!!! lol

no no to used CRAP !!!!

nGAbear · June 15, 2012

no no to used CRAP !!!!

X2!

00Silverado4x4 · June 15, 2012

x3, by time you verify the parts used are working or not you've already, potentially, cooked your engine.

Nichevo · June 19, 2012

OK, so...

Salvage yards exist for a purpose, right? What kinds of parts would you, would you not, would you maybe, would you NEVER EVER EVER buy used or salvage if there is a difference? People put in whole engines and transmissions used. I'll do what I have to do but I would like to understand instead of spending more money out of FUD (fear, uncertainty and doubt).

And then riddle me this. ACDelco has two parts, a Professional and an OE Service. Is the Pro acceptable or only the OE? Why? Why is a Chinese ACDelco pump better than a Chinese (or not) pump from another mfgr? Why is it better than a rebuild?

Or is it only some parts and not others? I've put a salvage EGR valve and MAF sensor in already. They seem to work like a charm. I bought a CV shaft for the left front axle, from Nordstrom's in South Dakota, advertised to have 3 (three) miles on it (hail damaged 03 Avalanche on dealer's lot). I had to do the LF wheel hub when I first got it last year - thought to go salvage, but was scared into buying new - but I rarely use 4WD so for at $30 for the shaft, vs $300 new ACDelco, I thought I'd try it. You think these are time bombs?