Water Pump leak... any advice?

[BlackTaz]

As best I can tell, the water pump is leaking on my 99 Yukon, 5.7 L. I figure this is a standard job, but this is the first time I've tackled a newer truck (my old one was an 80's model), so there's a lot more misc. and electrical stuff around. Any tips and tricks on making this job easier?

 

While I'm at it and have things torn apart, up front, is there anything else I should replace?

 

The truck has 63,000 miles on it, and quite a bit of rust from a tour in Canada.

 

Thanks!

[Willys33]

You may want to consider replacing the belt while you're at it. Keep the old one for a spare. Mike

[BlackTaz]

Here's an example... this seems stupid, but I can't find the petcock to drain the radiator! It's typically on the passenger side of the radiator on other SBC's. But I can't see anything and I can't get access to it from the underside because of the skid plate :-(

 

Is there a petcock in the block that I should/can use instead?

 

Seems like a stupid question, but if I can't find the petcock I can't find it!

[02 Silverado Z71]

...ahhh, don't worry about a petcock. Just drain the coolant by removing the lower radiator hose from the water pump.

Simple process; remove upper fan shroud, serp. belt, clutch fan assembly, spring clamps on bypass hose, water pump.

Just make sure that the new gasket surfaces are spotless!!

May want to flush and fill entire cooling system at this timel especially if it has never been done.

Also, check the condition of your serp. belt tensioner. If it has alot of freeplay TO AND FROM the engine block, replace it. Another way to tell if it is worn is to see if you can see the internal spring cover, usually tan or white, bulging out of the assembly.

That's about it!

[BlackTaz]

Alright... I'll just use the radaiator hose to drain the system.

 

On removing the fan clutch from the water pump... I can't get it to budge. A friend thinks these things are left-hand threaded. Anyone know, for sure, if the clutch bolts on to the water pump with normal (right-hand) thread or left-hand thread? Any tips on how to hold the water pump pulley so that I can unscrew the fan clutch? The belt doesn't seem to have enough tension.

 

Thanks!

[BlackTaz]

I managed to get the fan clutch off... it is right-hand threaded (normal).

 

Small progress... but progress

 

But, I can't get the lower radiator hose clamp off... I can just barely reach it and can't get a good enough hold to release the clamp... designed for easy access

 

So, I guess I'll have to go for the drain in the block...

[asepgrad98]

dont worry about draining it, when you take off the WP some will come out but thats OK.

[Ben]

Consider flushing and switching to green.

 

DeathCool is warranted for 5yr/100K miles and is supposed to extend watper pump life....

 

Also keep an eye on the intake manifold, as the leak could also be from it too. Infamous and usually appears around +/- 80K miles. Ditto the heater hose connection to the manifold, replace with brass or stainless with hose barb.

 

Make sure you get CCW rotation.

 

Consider new thermostat while there. Drill 1/8" dia hole in it's flange.

[BlackTaz]

Thanks for the help... I finally managed to finish this...

 

Here's what I learned in case it helps someone else. First of all, buy a decent shop manual... I've ordered the full set of shop manuals (GM), they just haven't arrived yet (wouldn't ya know it!). The Chilton manual I have is nearly worthless for this job... if you knew all about how to take this stuff apart, you wouldn't need the manual!

 

I couldn't get access to the lower radiator hose at the radiator... not enough room, so I just disconnected the hose at the water pump and tried to catch as much coolant as I could.

 

Don't be tempted to take the fan apart from the clutch... you don't need to. But, take the clutch off the water pump before you take off the belt (you need the tension). You will need either a huge open-end wrench... about 1 3/8", I think, or a big crescent wrench (12") and the clutch/fan comes off counter-clockwise. If the belt tension isn't enough, use a wrench (10mm) on the pulley bolts until the water pump pulley rotates around and the wrench runs into something... that will give you enough resistance to break the clutch free.

 

I used a putty knife to get off the old gasket material on the block and emery cloth to clean it up. I used some RTV sealant on both sides of the gaskets.

 

I pulled the knock sensor (7/8" socket) on the under-side of the block, on the passenger side, to drain as much of the rest of the coolant as I could... that's messy, too; it's hard to catch all the coolant.

 

I just refilled with 50/50 DeathCool and water because I'm in a hurry and had to make time for this today.

 

You can run the engine after all the hoses are tightened up, but without the fan/clutch installed, to check for leaks (that way, if you find a leak, you don't have to take the fan off again.

 

I hope this is helpful to someone out there that has to take on this job. Make sure you've got everything you need so you can avoid another trip to the parts store (which I had to do for the big crescent wrench... I've got open-end wrenches up to 1 1/4"... just not quite big enough!).

 

Cheers!

[Tucson_02Silverado]

One of the most important items with regards to the SBC GEN I is that the water pump bolts go through the water jackets and MUST be sealed. Locktite would do fine.

[99-2door]

BlackTaz, widh I had seen this post earlier, might could have saved you some headache. The Vortec 5.7Ls having water pump leakage is very common. They typically start leaking out of the weap hole on the bottom. Looks like you got it figured out though.

there is a tool available to remove the fan clutch from the water pump. It is a forked shape wrench that slips over the 4 bolts on the pulley so you can hold the shaft while you turn the big nut the clutch is held on with. In a lot of cases the nut is so tight that the belt will not hold the pulley tight enough. Usually available at your local parts store, most will loan you the tool for your job.

[BlackTaz]

Sounds like a good tool... I wish the guy at the auto parts store had thought of that when I asked "is there anything else I need for this job?". I didn't even think of this because the last time I took off a fan/clutch, it was all bolted together through the 4 bolts on the pulley.

 

And, yes, I do have a headache Maybe a beer will help that... I think I've earned it!

 

I didn't think to seal the 4 bolts that hold the waterpump on... now that you mention that, Tuscon, I think I kinda remember that from a long time ago... oh well, I'll keep an eye on it... if I see seepage, I may pull the bolts and seal them.

 

Maybe all this together will help someone else