Water Pump leaking badly after replacement!

[Webster3]

I just spent the day installing a new water pump. I removed the old one, cleaned the surface well... scraped off the old gasket and such. I got Blue RTV and applied a thin layer to the new pump, put the gasket on and put another layer on the gasket (engine side).

I then got it on and torqued it to about 90-100 inch lbs (but I've got a cheap wrench and I'm not sure how accurate it is). I then put everything back together and less than an hour later I fired her up only to see thin sprays of water coming from the bottom of the pump.

So, did I screw up? Should I have waited longer for the RTV to fully cure? I tried torqing it down a little more to 120 in. lbs but no effect.

If I wait for a few hours will this fix itself as the RTV sets up? Or am I screwed at this point... and is the only way to fix things now is to drain the system and pull everything apart again??

Help!!

Ed

 

[Rick]

I never use RTV for the water pumps. I always use something like High Tack. I think you may be screwed if the water "bored" a path through the RTV.

 

[Webster3]

That's what I was thinking too... but I still have hope for the same reason it may have leaked. I did crank the bolts down a little more right after I tested it and haven't started it since.... so I'm hoping that may have closed the holes since the RTV wasn't set.

I'll fire her up in the morning... if its still leaking I have no choice but to take it over to Pep Boys and have them fix it... they will charge me $200 but I can't miss another day of work.

If that happens I didn't save much money... but dispite the leaking I took a jump in my wrenching ability since the most complex thing I've done on the truck before this was brakes!

Thanks!

Ed

 

[ExplorerDMB]

water pumps are aluminum and can be easily split and warped if tightened too hard. 100 in/lbs isn't bad, but then again the only thing i really torque are wheels. Anyways, rtv should only have to set up for like 1-2 minutes before putting on. We use RTV sometimes on water pumps.

-Drew

 

[spindlecone]

Actual TQ value is 90 IN/lbs for the water pump, never use RTV and a gasket, RTV will destroy a gasket in short order.
as rick said, use High tack or coppercoat, RTV is best used on metal to metal parts such as diff covers

 

[dogfriend]

Where did you get the replacement water pump? I'm wondering if the surface on the new pump is warped or something. It doesn't seem like it should leak even if you didn't use RTV at all if the surfaces touching the gasket are flat.

 

[whisperer]

One of 2 things happened - both bad news. Either the pump is bad, cracked, bad surface, the new seal dislocated itself, or, the gasket slipped when you installed the pump (most likely). Either way you need to pull the pump back off and fix it. You just did the job - trust me, it will be 100% easier and take 1/2 as long to do the second time, even if you are cussin yourself at having to do it.

I do use automotive silicone on water pumps - lightly wipe the cleaned block surface with silicone, then stick the gasket to that. Then lightly wipe the pump surface with silicone, feed a couple of bolts into the pump and slide the pump into place feeding the bolts first into the proper holes to guide it. From there feed the rest of the bolts into their respective holes making sure the gasket hasn't slipped and snug it down.

Before you pull it off check very carefully to see where it's leaking from - if it is leaking from the little hole under the shaft take the pump back to where you got it and they will swap it no charge. If you just pull that pump off and re-seal it, and the pump was rebuilt wrong then it will just leak again.

 

[Papa]

When I replaced my water pump I asked the guys at Napa if the gasket needed any coating and the answer was a resounding no, just clean mating surfaces. I know from my work with large diesel engines that a lot of gaskets fail because both surfaces were not wiped with a solvent to remove any oil residue or other contaminants. I wiped mine with a little solvent and mated everything up no leaks. Yes identify exactly where it is leaking from and do not hesitate to take it back if it is a bad rebuild.

 

[Webster3]

Ok, it turns out it was NOT the water pump leaking after all! I also replaced the thermostat at the same time and apparently when I put the housing back on, the themostat fell slightly out of its spot and the seal got caught when I cranked it back down... which sliced a piece of it right off. I couldn't tell exactly where the leak was coming from when I looked... so I assumed it was the pump itself.

So I feel better about the job I did... actually the haynes manual, the little instruction sheet that came with the pump, and the write-up from this forum: http://www.explorerforum.com/Singleton/web/pages/waterpump.html all say to use the RTV with the gasket. Also, the mechanic at Pep Boys said they use RTV when they do this job. It does sound like the High Tack is better though.

Thanks for all the replies gentlemen... its good to know I can count on my fellow Explorer Owners to help out when I am in trouble!

Ed

 

[will123345]

So what is the final determination as to what kind of sealant to use?

I am having an issue with the seal on my current water pump installation. I first did the installation using permatex #9 tack and seal. Coated the block, both sides of gasket, and then the water pump. Waited for it to get tacky, then put the pump on and torqued to spec. Waited till the next day(about 16 hours) to turn the truck on. I have a small leak on the top right side of the pump.

Back to the auto store i went. Talk to the sales guy there, he was recommending the blue rtv or just put it on dry. A mechanic happened to walk in by chance just then, he recommended the permatex 97 to just hold the gasket it place during installation. He also said to use the felpro gasket with the bead of silicon in the gasket. He said the tack and seal does nothing for the seal, only holds the gasket in place for easier installation.

Well i tried that method, I'm waiting 4 hours to turn the truck on just in case the permatex needs to seal. Any input or experience would be greatly appreciated! I'm pretty mad at the truck right now. It's a '96 xlt ohv 4.0.

 

[cross6]

I use blue RTV on water pump gaskets and have never had a leak or a gasket fail. RTV does not 'eat' gaskets.

 

[mbruffey]

I always use Indian Head shellac on all surfaces for thermostats. Guess that makes me an old timer.

 

[2Kexplorerxls]

IndianHead it is its the BEST!!!