weeping bolt holes

[DaveBr]

I had the waterpump replaced and it started leaking a month later. I started into the project to fix the leak and found that it is coming from two 4" long bolts that go through the pump and into the head on the passenger side. I removed the bolts, cleaned and coated with thread sealant and reinstalled. No joy, still leaking. Is this fixable or could a stop leak of sorts be used?

[DmaxMaverick]

Make sure the bolt holes/threads are clean (use brake cleaner, but not too much or you could contaminate the coolant). You need to use anaerobic thread sealer on these. If you use anything else, including RTV, it can take a week or more for it to cure and seal up (before you try to use it). Also make sure your gaskets (and/or gasket maker) are sealing well, or it will leak around the bolt shank. I use Loc-Tite anaerobic thread sealer on the bolts, and orange Permatex RTV on both sides of the thin paper gaskets.

[Robyn]

Those bolts you speak of do not go into the head.

None of the holes on the front of the head go into water.
The long ones go through the timing cover and into the front of the block.

I have used various sealers, from good old Permatex to RTV and never had issues with the threads.

What is likely happening is that the leak is between the block and the timing cover and has found a path into one of the bolt channels and is then leaking out by the bolt head.

The water pump has a steel plate on the back of it that is sealed to the pump with a gasket and to the cover with a sealant.

My best guess without seeing it, is that the leak is between the plate and the cover.

The only way I will do these is by using the Felpro gaskets that cove with the water pump gasket set.

Clean everything well and then install the gaskets to the pump with some High temp RTV then install the plate to the pump.
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Be sure to use a little Blue loctite on the bolts that are inside the timing cover to make sure none of these can come loose and fall into the timing gears.
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Install the gasket to the back of the plate using High temp RTV

** Sparingly on the RTV, just enough to seal the gasket to the parts**

Now, the timing cover can leak where it contacts the block but thats not the usual trouble spot.

If things look nasty, you may want to yank the ballancer and then the cover and start fresh at the block and do it up right.

I do not recommend the anerobic sealer on any of this stuff.

Its fine once when things are new, but on used parts, the gaskets and RTV have never failed to bring joy at my house.

With the fan shroud, fan and other accessories out of the way, this is a pretty easy job.

Make it clean and it will do fine.]

Just make sure that the steel plate does not have any serious corrosion on the inside next to the impeller that could rot through and dump coolant into the engine.

I use RTV on the bolt threads that go to water and never had any issues so the problem is after the block threads.

Rip at all apart and make it good from the block out and joy will follow :)

Missy

[DaveBr]

You are right Robyn, the bolts are in the block. The leak is not at the bolt heads it is weeping where the timing cover meets the block. I can watch it slowly get wet at the block. However when I loosen the two bolts the weeping becomes a definate drip. I can see that the garage used anrobic sealer. I have purchased a new felpro gasket kit and will proceed after it quits snowing and spring returns. About how many hours am I looking at to do this job?

[Robyn]

Two choices

Try some cooling system tabs (ma General store)
Pull the thing apart and redo the entire cover gaskets and such.

My worry is that it could start leaking inside.

There are grooves that are supposed to keep any coolant that seeps past that passage directed out and not allow it to go inside.

The coolliing system tabs may do the trick, but I have never been a fan of the sealer goop/leak stop

To do the entire thing, you are going to have to remove the timing cover. Be sure to mark the IP and the cover as you will have to separate the entire set up.

This also requires that you keep the timing marks in line.

Just roll the engine over by hand until the timing marks for the cam gear and the pump gear are aligned, then pull the gear off the IP and then remove the 3 nuts that hold the IP to the cover.

Just mark the cover then all will go back fine.

Leave the pump, lines and all intact. No reason to mess with them.

Pull the serp pulley, ballancer and stuff then the water pump followed by the cover.

Remove the front pan bolts, and dont forget that there are some bolts inside the cover right behind the pump gear up top.

Use blue loctite on these when reinstalling to prevent them from coming loose.

Clean the front of the pan really good and when reinstalling, goop it good with the RTV High temp silicone and install the cover.

RTV the gasket to the covers engine side and align the holes well and allow the RTV to tack good so the gasket does not shift when you install the cover.

Be sure to place a good Fillet of RTV in the corners where the covers lower inside edge meets the pan and the block.

Replace the crank seal too, just because you can.

Pretty easy, maybe 3-4 hours in good weather with no interuptions and tools handy.

Missy

[Kennedy]

Just drop a "cadillac tab" in teh system and be done with it.

Seriously see the dealer and ask for a cooling system seal tab. They work and don't clog stuff up.

If this does not work the worst of it is that you'll have to pull it apart.

[DaveBr]

Robyn you have definately supplied the right way to fix it with all the necessary info to do it. For that I thank you. But the fact remains that I am a man and JK has supplied the easy way out so I will try the Cadillac tab as suggested. If it fails I will print your post and follow the instructions.

We have a TV show in Canada called Red Green. At the end of each episode all the men gather for their lodge meeting and repeat the Possum Lodge Creed.

"I'm a man... and I can change... if I have to...I guess"

[racer55]

The tabs from GM like mentioned by Robyn and JK are the best I have ever used(to date) for patching small leaks.

They are put in every new engine at the factory before startup to prevent leaks also.

[Robyn]

OHHHHHHHHHH Yessssss

The caddy tabs are certainly worth a try.

As mentioned, the worst case scenario is that you will have to take it apart and replace the gaskets.

Good luck

Missy

[DaveBr]

Sooooo, I went to the dealer and bought the caddy tabs. All of $5.00. Took a short cut through the show room and bought a new Silverado. Turned out to be the most expensive trip I've ever made to the dealer.