v345 lower left water pump bolt leak

B

Bob Prohaska

Member
It looks as if the lower left water pump bolt is leaking on a
'72 v345 (auto trans, ps, A/C). Am I correct in thinking this
is one of the bolts threaded directly into a water passage?

Far as I can tell the pump seal is ok so I'd rather not blindly
replace the pump, which has only about 30k miles on it, all
with good coolant. I'll check more carefully to make sure.

Does anybody have suggestions for thread sealants, or maybe
using a copper gasket under the bolt head? Is there enough clearance
to get the bolt out by itself? My last work on the pump was over 30
years ago and I don't remember how I did it 8-(

The Scout isn't driven daily, but it is driven when needed, so
I have some time to explore the problem with a pressure tester
and wait for guidance I've got the wrench needed to remove the
fan and shroud but don't relish the prospect.....

Thanks for reading,

bob prohaska
.
 
Are you talking about the 4 small bolts the mount the pump to the pump housing or the 3 3/8 bolts that mount the housing to the block?

Neither penetrate through to the coolant.

If one of the 4 smaller bolts are weeping at the bolt head, it is getting around the gasket and emerging from around the bolt
 
Robert Kenney said:
Are you talking about the 4 small bolts the mount the pump to the pump housing or the 3 3/8 bolts that mount the housing to the block?
Click to expand...
Lower leftmost of the 4 small bolts. Just put a wrench on it, not at all loose, so there went my first hope :cool:

Robert Kenney said:
Neither penetrate through to the coolant.
Click to expand...
I guess that's good, but I wonder how the possibility entered my head.
Robert Kenney said:
If one of the 4 smaller bolts are weeping at the bolt head, it is getting around the gasket and emerging from around the bolt
Click to expand...
Rats! Guess it's time to pull the fan and shroud... Does the weep hole for the pump seal
put coolant on or near the bolt? It would be easier to understand a leak at the shaft seal,
rather than a tight bolt that hasn't moved since 1998.

Thanks very much for the prompt and informative reply!

bob prohaska
 
Bob Prohaska said:
Rats! Guess it's time to pull the fan and shroud... Does the weep hole for the pump seal
put coolant on or near the bolt? It would be easier to understand a leak at the shaft seal,
rather than a tight bolt that hasn't moved since 1998.
Click to expand...
Well, it wasn't the bolt after all. The shaft seal leaks and coolant
runs over the bolt. Time for a new pump.

It bugs me a little to throw away a working fan clutch, but the OEM
screw-on style I have appears to be very scarce and a bolt-on fan
clutch together with a matching water pump are together cheaper
than the OEM style water pump. Is there any reason to _not_ make
the swap now?

Thanks for reading!

bob prohaska
 
Scoutboy74 said:
Nope. Bolt on is the practical way to go.
Click to expand...
Will the OEM-style fan fit the new clutch?

Anything extra required for a stock engine,
shroud and radiator setup? I'm thinking
spacers, bolts and sealants; I have #2
Permatex (soft) and I usually put grease
on the opposing surface to ensure
easy disassembly.

Thanks for writing!

bob prohaska
 
I think the fan bolt spacing is the same on the two clutch bodies. You just can use a direct bolt fan with a clutch and vice-versa. I use a very thin skin smear of something like copper gasket whatchamacallit for any surface imperfections along with the paper gasket.
 
Scoutboy74 said:
I think the fan bolt spacing is the same on the two clutch bodies. You just can use a direct bolt fan with a clutch and vice-versa. I use a very thin skin smear of something like copper gasket whatchamacallit for any surface imperfections along with the paper gasket.
Click to expand...
Ok, thanks for the quick reply. I'll put in the order....

bob prohaska
 
When I did mine the big nut fan didn't fit the new 4 bolt fan clutch. There are a lot of different clutches to choose from. There is % power to the fan below lockup temp and different lockup Temps.
 
FDChappie said:
When I did mine the big nut fan didn't fit the new 4 bolt fan clutch. There are a lot of different clutches to choose from. There is % power to the fan below lockup temp and different lockup Temps.
Click to expand...
That's worrisome. The new pump and clutch are on the way already, I hope the existing fan fits.

In what dimension(s) did the new clutch not fit the old fan?

Thanks for the warning!

bob prohaska
 
Clearance between water pump hub and front of radiator will be a primary determining factor in fan clutch selection. The more stout the clutch, the bulkier it is. Your only option may be to go with the standard duty offering. You can Google the Hayden online catalog which lists the attributes of every fan clutch they offer. It helps to know the number of the standard duty clutch that fits the IH 8 hole WP hub to compare it's overall length with your available space and then see if a heavier duty version with similar attributes would fit. I used to have the standard duty number committed to memory, but that's been too many wobble pops ago. You want at least 3/4 inch clearance between clutch face and the rad. A bit more is better. Another factor is the amount of blade surface inside and outside of the fan shroud. Optimally, it should be about 50/50. What we see is more like 80 percent blade inside the shroud and 20 out. Not really much to be done about that.
 
Scoutboy74 said:
Clearance between water pump hub and front of radiator will be a primary determining factor in fan clutch selection. The more stout the clutch, the bulkier it is. Your only option may be to go with the standard duty offering. You can Google the Hayden online catalog which lists the attributes of every fan clutch they offer. It helps to know the number of the standard duty clutch that fits the IH 8 hole WP hub to compare it's overall length with your available space and then see if a heavier duty version with similar attributes would fit. I used to have the standard duty number committed to memory, but that's been too many wobble pops ago. You want at least 3/4 inch clearance between clutch face and the rad. A bit more is better. Another factor is the amount of blade surface inside and outside of the fan shroud. Optimally, it should be about 50/50. What we see is more like 80 percent blade inside the shroud and 20 out. Not really much to be done about that.
Click to expand...
That sounds like an issue with axial dimensions, not radial. I ordered the clutch and pump yesterday from IHPA, speaking with
MJ, which should arrive this evening. He did indicate that I needed the "short" clutch. Now I understand better.

A factory manual came with the Scout. The car came with a screw-on fan clutch, but the manual shows only bolt-on clutches.
Any idea why the mismatch? It's a '72 California model, if that matters. It also has no EGR valve and uses a road-speed-controlled
vacuum advance for NOX control, which I gather _is_ a California distinction.

Thanks for writing!

bob prohaska
 
Bob Prohaska said:
That's worrisome. The new pump and clutch are on the way already, I hope the existing fan fits.

In what dimension(s) did the new clutch not fit the old fan?

Thanks for the warning!

bob prohaska
Click to expand...
The bolt circle of the fan is larger than the one on the clutch. If you got the clutch from IHPA it might fit. haydenauto.com has all the details about their clutches.
 
FDChappie said:
The bolt circle of the fan is larger than the one on the clutch. If you got the clutch from IHPA it might fit. haydenauto.com has all the details about their clutches.
Click to expand...
No such luck. The existing fan has a 3" bolt circle and a 2 3/8" center hole.
The new clutch has a 3 1/4" bolt circle and a 2 5/8" center hole. Any suggestions
would be appreciated. I'll pay a visit to my favorite parts store on Monday.

More puzzling is the water pump. The manual calls for .015" end clearance between
the rotor and pump casing with the gasket in place. I'm seeing many times that,
.040-.080", with no gasket (which is ~.030"). That's far too much by the book.
Do I misunderstand something here?

Clearance between radiator core and fan clutch face is about an inch and a half.
So far that's the only good number to hand....

Thanks for reading!

bob prohaska
 
Last edited:
Scoutboy74 said:
Here's this one:

www.ihpartsamerica.com

Fan for IH Engine w/ Bolt -On Fan Clutch Mounting

Check out the deal on Fan for IH Engine w/ Bolt -On Fan Clutch Mounting at IH Parts America
www.ihpartsamerica.com

Can't help with your other question. I've always just installed the new WP with the gasket and called it good.
Click to expand...
Did the same here. Maybe the .015" clearance was needlessly difficult to set and people
just quit worrying about it.

The new pump is in, so I decided to do a dry leak test with air. After snugging the bolts
on the pump to 17 ft-lbs the system decays from about 5 psi to about 2 psi in ten minutes.
That's faster than I expected, but the paper gasket is dry and maybe slightly porous still.
If anybody considers this excessive please let me know.

Thanks for everybody's help!

bob prohaska
 
Bob Prohaska said:
The new pump is in, so I decided to do a dry leak test with air. After snugging the bolts
on the pump to 17 ft-lbs the system decays from about 5 psi to about 2 psi in ten minutes.
Click to expand...
After sitting overnight the leak improved only slightly, so I measured the
out-of-flat between pump and volute. About .012" with three bolts snug
and one loose. At one-third of the gasket thickness, maybe too much.

I had some 3/32" teflon cord sold as valve bonnet seal packing and
decided to try that. Getting the cord, which is very soft, to stay in
position during assembly took a film of aviation Permatex and some
luck in assembly. It worked on the second try, with a simple overlap of
the cord to finish the loop. The four bolts bottomed metal-to-metal,
no gasket material extruded. No pressure loss at 5 psi over two hours.

I'll raise the pressure to something near working, maybe 10 psi, and
let it sit overnight to see of anything changes.
 
FDChappie said:
Sounds like housing is not mating to the pump correctly. Perhaps it is warped.
Click to expand...
It appears that both pump and housing are warped. The flattest test surface
I have that fits is a lathe chuck backplate. It rocks when placed on the pump
sealing surface, but only about a quarter as much as the pump does

It looks as if the teflon cord gasket is holding reasonably well, certainly much
better than the stock paper gasket: Set near ten psi last night, it was still near
five psi this morning. Compared to the ten minute leakdown with the paper
gasket that seems pretty good.

Next I'll run the bolts down to 15 ft-lbs, raise the air pressure to 10 psi and
do a soap bubble test.

Thanks for reading!

bob prohaska
 
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