Water Pump Gasket Sealer

My back plate to pump gasket (SBF shorty pump) failed some time back and I found that the two thin head bolts that support the long span on the bottom back were loose out of the box, and the gasket had no type of sealer on it, either. Got new gaskets, put it all back together, and now 1100miles later I've got a drip again, looks like from the bottom sealing surface of the pump to the timing cover so the front drive is coming apart again :mad:**)
My question - What type of sealer do you use on water pumps these days? If you use blue RTV do you use the paper gasket, or do you just use RTV alone? I've got a plan, but wondered what others are using, just for grins.

Roger - I try to never use RTV/silicone on anything engine wise but the ends of the intake manifold to valley. What I've had the best luck with on water connections is ordinary (flammable) DAP contact cement. Of course, the Edelbrock Gasgacinch (sp?) will work as well as it is contact cement with a higher price tag:LOL: I also only use Fel-Pro gaskets.

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Originally Posted by IC2

Roger - I try to never use RTV/silicone on anything engine wise but the ends of the intake manifold to valley. What I've had the best luck with on water connections is ordinary (flammable) DAP contact cement. Of course, the Edelbrock Gasgacinch (sp?) will work as well as it is contact cement with a higher price tag:LOL: I also only use Fel-Pro gaskets.

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I've got Gasgacinch, but have not used it in this service. Is your approach to coat all four surfaces (block, both sides gasket, pump) and let them set, then assemble?

Roger, you may remember that I posted a while back that I am on my 3rd short Ford Racing water pump due to exactly what you have going on. The first one started dripping water out of that spot after a few miles........airfreighted a new one in and I got as far as Daytona before the second one blew out that same gasket at the bottom. I bought some gasket paper and glued the heck out of the new gasket I made, and while I was at it I found the same two bolts loose on my pump.

That pump lasted the weekend and blew again on the way home on Sunday, so I trailered the car home and let it sit until I felt like looking at it again. When I tore it down I found the diffuser plate inside had come loose from the vanes and chewed up everything inside. I called Ford Racing and the guy there told me "We leave those bolts loose on purpose so you can apply sealant to the gasket and then tighten them down." :eek: I've been installing water pumps for 50 years and never had to tighten those up, even on reman pumps.

Anyway, I finally figured out that the Zoops pulleys I was running were overdriving the water pump by maybe 50% or more, so it was blowing the pumps apart. I found a company named Runne Rite and they make the correct pulleys which I installed. After all that I now have hundreds of miles on the car and it runs cooler and no more water pump issues. I mention this because you may have a similar issue going on.

As for sealant on that gasket, I used Permatex Gray and it seems to be fine.

Don

I learned a long time ago to check those back plate bolts on all water pumps,can't tell you how many times I have found them loose on brand new out of the box pumps. Far as sealers, Peramatex Ultra copper is the only silicone I'll use and only on exhaust applications. I use Permatex RIGHT STUFF on everything else. Stuffs a little pricey but worth it. I use it for gasket sealer,but works very well when you don't have a gasket. Only drawback is it makes things hard to get apart.

Yep, the Right Stuff is really good stuff and also hard to remove. We had sealed up the intake manifold ends with it on my Sons 455 Olds and a week later when we removed the intake I thought the stuff was never going to break free. I actually worried about cracking the intake manifold as I was prying it up.

Don

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Originally Posted by rspears

I've got Gasgacinch, but have not used it in this service. Is your approach to coat all four surfaces (block, both sides gasket, pump) and let them set, then assemble?

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Yep coat them all. And of course I see differing opinions - and they probably work as well, but if it's silicone/RTV......I don't/wont use there

Concur with all the above - no silicone here and I really like the Permatex Right Stuff - it's got some type of rubber-like compound in it that seems to be pliable, fills little microscopic imperfections, and impervious to the heat generated in the water pump application. I use a little bead on all sides and assemble right away as this - stuff starts to set right away.

(I used a lot of Gasgacinch when building dirt bikes (two-strokes) and it seemed to work well for cases and water passages - also really easy to take apart. But you're not wanting to take your pump apart on a regular basis!!)

I talked to Brad at Rocky Hinge, and he also said that those back bolts are left loose, but his reason was to allow alignment of the back plate with the bolt holes!! I've learned my lesson on those two bolts, and they will not be ignored again. On the Right Stuff, my concern is that they say that all bolts are to be at final torque within five minutes, and that's going to be a challenge with this front drive unit, getting all of the pieces, parts and spacers in the right places, and then getting everything tight in order. It's all apart now, but I had to pull the radiator to get access - simply too tight to get everything out!

What pulleys are you running, Roger? What are the sizes of the crank and wp pulleys?


Don

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Originally Posted by Itoldyouso

What pulleys are you running, Roger? What are the sizes of the crank and wp pulleys?

Don

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Rocky Hinge billet pulleys, 6" crank, 5" water pump, both measured across the OD, not down in the belt groove.

There is your problem, Roger, you are overdriving that pump by having a smaller pulley on it. That was my problem too. The correct pulleys were discontinued by Ford Racing but Runne Rite used to make them for Ford and still carries them. Once I ordered the right ones it was VERY apparent I was killing the pumps myself by having the wrong pulleys on them.

In the picture below the pulleys on the left are the wrong Zoops pulleys I had on it. The ones on the right are the correct Runne Rite pulleys, You can see how overdriven it was, and yours is similar. You will never keep any gasket in that pump with that overdriven condition..............I had to learn the hard way, about $ 1500 dollars worth of screw ups later, if you factor in 3 pumps, two sets of pulleys, U Haul truck and trailer to bring my car back from Daytona, etc. But it is finally working great after I got the right pulleys.

Also, I don't know if you can see on Don's car (blue one) but the stock Ford wp pulley is huge compared to the crank pulley, slowing it down even more.

Don

BTW, here is Runne Rites website: (Oh, and all of those pulleys shown are billet aluminum, they just photographed black for some reason.....reflection?)

http://runne-rite.com/pulleykits.html

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Originally Posted by Itoldyouso

There is your problem, Roger, you are overdriving that pump by having a smaller pulley on it. That was my problem too. The correct pulleys were discontinued by Ford Racing but Runne Rite used to make them for Ford and still carries them. Once I ordered the right ones it was VERY apparent I was killing the pumps myself by having the wrong pulleys on them.

In the picture below the pulleys on the left are the wrong Zoops pulleys I had on it. The ones on the right are the correct Runne Rite pulleys, You can see how overdriven it was, and yours is similar. You will never keep any gasket in that pump with that overdriven condition..............I had to learn the hard way, about $ 1500 dollars worth of screw ups later, if you factor in 3 pumps, two sets of pulleys, U Haul truck and trailer to bring my car back from Daytona, etc. But it is finally working great after I got the right pulleys.

Also, I don't know if you can see on Don's car (blue one) but the stock Ford wp pulley is huge compared to the crank pulley, slowing it down even more.

Don

BTW, here is Runne Rites website: (Oh, and all of those pulleys shown are billet aluminum, they just photographed black for some reason.....reflection?)

Pulley Kits

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Don,
I'll definitely keep that in mind and will keep that RunneRite link in my back pocket, but in my case I think I found the culprit in a bolt not being torqued to spec at a critical point, leaking around one of the pump ports on the plate to block surface. With the Street Drive unit three critical points at the water ports are threaded billet spacers that must first be tightened on the pump, then the outer bracket tightened to that spacer. One of mine was not tight at the pump.:o
I've finally seen that on this pump all around the back plate to pump is a critical seal; but on the pump back plate to block the critical point is only around the two water ports into the block. There's a weep hole relief at the bottom of the raised sealing surface on the front cover, and any coolant that gets out from the pump inlet/outlet seal area drips from that weep relief. The pump to block seal could just as easily (and maybe more effectively) be a pair of O-rings at the ports, with nothing around the rest of the pump, but it is critical that the entire surface be equally tightened to seal the plate to pump surface.
Attachment 50249Attachment 50250
You can see here that mine shows evidence of port leakage from both stains on the pump and the front cover, but the weep hole at the bottom was totally blocked with RTV :o so it held for a while. Also interesting to me is that if you look at the front cover there are three holes around each of the ports (inner ones still have blue RTV in them), but on this pump only the two outside perimeter holes are used on each side, leaving the inner load around both ports to be picked up by other perimeter bolts. It would be a much better pump design to have two more bolts at the ports, but we live with what the OEM designer gave us....
Like I said, a pair of RunneRite pulleys may still be in my future, but I think I'll pull the back cover, inspect the impeller, and if OK install the back cover being sure it is sealed 100%, then reinstall the pump and the rest of the junk. Can't check for leaks until the radiator is re-mounted and buttoned up **)

Roger, the only places you should have to put any sealant is around the 2 water ports, as marked in red, and also on the four bolts that go into the water passages, 2 of them also in red. Sealant around the entire perimeter does nothing but make the pump hard to replace.

Don

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Originally Posted by Itoldyouso

Roger, the only places you should have to put any sealant is around the 2 water ports, as marked in red, and also on the four bolts that go into the water passages, 2 of them also in red. Sealant around the entire perimeter does nothing but make the pump hard to replace.

Don

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Don,
I agree, but as shown on the back side of the pump there's no bolt in that hole you circled on the left side when looking at the timing cover - it's just a flat spot on the pump backing plate. The one on the lower right indeed needs RTV on the bolt threads. I think that a better pump design would have had two added bolts, one in the hole you circled, and one on the other side, immediately above the hole you circled, at the inner corners of the ports but there's no holes on the pump in those two spots. The sealing pressure has to come from the next bolts up, adjacent to the top center bolt on each side.

Yeah, it was hard to tell from the picture, but basically, any bolt that goes into a water passage would need sealant.

Don

Don,
Got it back together, and no initial leaks so things are looking up!! I used the tried & true No 2 Permatex Non-Hardening Formula, and put it in all of the critical points.

Looking at your original pulleys and scaling from the pictures if I assume that the original crank pulley was 6" your water pump pulley scales to about 3 7/8" which is an overdrive ratio of right at 1.55 to one which is pretty severe - your water pump was cranking more than three revolutions for every 2 of the crank, or at 2000rpm your water pump was seeing 3100rpm. Not saying mine is good, but I'm overdriving 1.2 to one, so at 2000rpm (70+mph for me) my water pump is cranking 2400rpm. At my idle of 700rpm my water pump cranks 840rpm, which is not a bad thing. My stock 1990 F150 is at 1.35 with a 6.75" crank, 5" pump so logic tells me my setup should be OK, but time will tell.

I truly appreciate the link to the RunneRite products, and all of the input that everyone has provided.

No, they weren't that far off in size. The crank is about 6 inchse and the wp is about 4.5, but still enough to overdrive the wp quite a bit. It must have really been firing the water through the block, especially at 3000 rpms on the highway.

Don

I use the aviation sealer, the thick black brown stuff, seems similar to Permatex #1 hard set and #2 somewhat pliable. at any rate disassembley can be eased by coating one side, ex block, with a lite coat of oil then wiping off comes apart easley, learned my lesson the hard way no silicone on anything that can vibrate. Clean up of surfaces is simple with air powered 90* scotchbrite pads grinder.

Roger, the problem of the gasket potentially leaking due to excessive pressure is not the most serious concern. What IS a potential problem is that overspinning the pump can tear the impeller and diffuser plate apart. That is what came apart on me in Daytona and made such a racket I thought the engine had broken a rod.:eek:

The diffuser is only lightly spot welded onto each vane and it doesn't take a whole lot to break those welds loose. when that happens the pump is gone. Here are some pictures of the pump that ate itself up. At about $ 150 a pop it gets a little pricey, making a new set of pulleys at a couple hundred bucks not such a bad deal. My breakdown happened about 250 miles from home, and that kinda puts a damper on the day. :LOL:

BTW, that cup shaped plate used to be a flat plate. Somehow it got deformed inside the pump and came out looking like that. This was a brand new pump with only about 250 miles on it.

Don

Don, I remember when you posted those photos before, after getting home and finding the problem, and I agree it's hard to imagine how that diffuser plate deformed like that. It had to be bouncing around like crazy, using the inside of the pump cavity as the dolly, and the noise?? I actually looked at the plate on mine yesterday, and especially at the spot welds but couldn't recall if you added a tack weld to your newest one or not. As you say, the spot welds are not real big, but then again how many pumps are out there doing just fine, and with varying degrees of overdrive from the factory? Just takes one, though, right? I also know it would be a real challenge to change mine without pulling the radiator & grille - might be done, but it'd be a task.

When I originally read Don's thread and with some interest, I was concerned that others might have the same problem. I wandered a Mustang forum, the Ford Truck as well as the Ford Muscle Forums (lurked, anyhow) but didn't find much in the way others who had had that problem. It almost appears that the Motorsport pump may be the culprit as I didn't see any others that had failures from over driving that pump. With the short radiator and possible filling problems and air bubbles, possibly those pump failures could be attributed to cavitation and heating of the the steel to weld failure, but not to the point of discoloring the base steel excessively. There are just too many that run those smaller pulleys without a problem.

Well, actually, Dave, I kinda created this problem myself. When I was putting the short pump assembly together I ran into the fact that Ford Racing had discontinued carrying the pulleys. I called around, trying to find some V belt pulleys to work. First stop was March Pulleys, they are right down the road from me in Naples, Fl. They were absolutely no help and were quite curt on the phone. Finally, I found that Zoops made pulleys for sbf, so I called them and got a crank and wp pulley they carried. The crank pulley didn't quite line up so I bought a Ford Racing spacer and had a machine shop modify my new Zoops pulley to fit it. Everything lined up and worked fine, except the ratio was off...........that was the problem I didn't forsee.

After 2 water pumps failed I decided to cure the problem once and for all, and that is when I learned that Runne Rite existed and had made the original pulleys for Ford Racing. Once I had those in hand I could see why I was having a problem, the ratio difference was so obvious. So, in fairness to Ford Racing, it was my choosing the wrong pulleys that caused the problems I was having.

Don

Don,
I have a theory that we may be both on the track. Your over driven pulleys are trying to move more water simply due to the fact that the impeller is moving at significantly higher speed. This in turn is creating water flow that can't move through the radiator fast enough. Your radiator is quite low which means that it may not totally flood the pump 100% of the time. Air bubbles are entrained in the water and cavitating in the water pump. This water is at the 180-190 degree operating temperature, but those bubbles are actually caused by the water boiling - and since it's under pressure and a 15 pound cap moves the boiling point to over 250 deg F and possibly (probably) even more in a localized area of higher pressure caused by that over driven water pump. Since your past life was with marine engines, think of an aluminum outboard prop that for some unknown reason shows erosion - that's often from cavitating. OK, now there are a couple problems - that pump is cavitating from being over driven then Ford and a less then satisfactory supplier, built a pump with crappy spot welds. Add that boiling water from cavitating, a poorly manufactured part and water, even not cavitating becomes almost a solid block when struck at speed (think of that last fall you took while water skiing- ouch!) and now you have a recipe for failure.

That makes a lot of sense to me, Dave. The pressures inside that pump must have been pretty high to deform the diffuser plate like that and to tear it loose from the vanes. I bet that sucker was spinning at 5,000 rpms when I was going down the road at 3,000 crank speed............and I had been going that speed for 5 hours or so on the way up to Daytona.
Don

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Originally Posted by Itoldyouso

That makes a lot of sense to me, Dave. The pressures inside that pump must have been pretty high to deform the diffuser plate like that and to tear it loose from the vanes. I bet that sucker was spinning at 5,000 rpms when I was going down the road at 3,000 crank speed............and I had been going that speed for 5 hours or so on the way up to Daytona.
Don

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I think Dave's analysis is a good one, and I had not considered the increased temperatures that would be present with cavitation, and both the higher temps and the forces of cavitation would be working on the spot welds. Also, a difference for me is the only time my engine sees 3000rpm is if I'm playing, and then it's not holding there for extended periods since 3000rpm in 5th gear equates to about 105mph for me.