1973 AQ130c/270 water pump breach

wm_son

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Aug 12, 2009
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Looking at the front of the engine, the pump is mounted next to the crank on outside of the timing chain cover. Pump inlet and outlet run horizontal with the inlet coming from the right side of the motor. Getting no pumping when testing in barrel full of water that covers the cavitation plate. Old impeller was trashed, and I have replaced with new.

Now, in all my research on this subject, it appears you cannot have a breach (air leak) anywhere in the lines that are involved here. I've read about the inlet pipe located on the outdrive, but before I inspect that, I would like to ask about the inlet and outlet connections on the pump itself. These connections are copper tubes that merely slide into the pump and are sealed with what appear to be rubber grommets/seals inside the pump housing. It seams as though this is causing the breach. Do these tubes get soldered into the pump? Is there a sealant used to seal these connections? Thank you.
 

alldodge

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barrel full of water that covers the cavitation plate

I think your problem is the barrel of water, you need muffs and a garden hose. Depending on how long you ran the motor, might need to replace the impeller again
 

Scott Danforth

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either put your boat in water to get the water level as high as the crank centerline of the motor or use muffs

you will never get the pump to prime with that much head trying to suck out of a barrel. As AllDodge pointed out, you probably toasted your new to you impeller
 

wm_son

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I can appreciate both of your replies; however, my water level is 8" above the intake louvers near the bottom of the outdrive. Are there additional water intakes that I'm not covering here? I have basically simulated the same as it sitting in the water. So picture it dockside in idle; you telling me the water pump won't pump in this scenario? Do you put earmuffs on your outdrive when it's idling dockside? Just curious.

I have inspected the water pump post test, and it is not damaged primarily due to the glycerol lube applied at install. That and the fact I ran for less than 1 minute.

Back to the meat of the matter please which was not addressed in either reply, and that is, are these inlet tubes a possibility for a breach of air? Do they need to be soldered to the water pump? Is that the norm that they just slide into the water pump housing. Do the seals/o rings go bad here? Are there sealants to be used here? Thank you.
 

kenny nunez

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If the seals at the water pump connection are soft they are probably good. Check the flexible hose that goes from the drive to the transom connection for cracks. Sometimes the nipple that the hose attaches to on the drive is corroded and broken.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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I can appreciate both of your replies; however, my water level is 8" above the intake louvers near the bottom of the outdrive. Are there additional water intakes that I'm not covering here? I have basically simulated the same as it sitting in the water. So picture it dockside in idle; you telling me the water pump won't pump in this scenario? Do you put earmuffs on your outdrive when it's idling dockside? Just curious.

I have inspected the water pump post test, and it is not damaged primarily due to the glycerol lube applied at install. That and the fact I ran for less than 1 minute.

Back to the meat of the matter please which was not addressed in either reply, and that is, are these inlet tubes a possibility for a breach of air? Do they need to be soldered to the water pump? Is that the norm that they just slide into the water pump housing. Do the seals/o rings go bad here? Are there sealants to be used here? Thank you.

when you start the boat, water is much higher than 8" above the intake ports. its more like 18" above the intake. the whole drive is under water. you have not, nore can you simulate sitting in the water. the crank centerline is 3" below the top of the drive. you need to get water to that height. its just the way it is.

now if you had a drive with the water pump in the lower unit, the pump would be submerged enough to self prime.
 

wm_son

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Aug 12, 2009
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Thanks all; appreciate the info and tips; I'll report back upon further investigation.
 

wm_son

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Aug 12, 2009
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20
No Title

I gave her a big drink of lake water today, and she pumped water. I found a replacement pump as shown in pics and eliminated the tubes and rubber grommets from pump #1. Problem now though is the new pump has grease points on top and bottom of housing (I'm assuming they're grease points). You should be able to see in 2nd pic. Well, water is spraying out of the bottom hole. No water coming out of top hole. Do I need to seal these holes (epoxy) or is there a seal in the housing that needs replaced? Special tools to get to that seal?

If it's the seal in housing, then I may revert back to pump #1 and deal with the tubal situation. Problem here was that the ingress tube was falling out of the pump housing. The rubber grommet is intact, but evidently it's shrunk. Both grommets are pliable. I can probably find replacement grommets to seal the fittings. Seems odd for the system to have this type of fitting when the goal is to have air tight. Solder the copper tubes into the pump housing? Is that an option? One other drawback from using this pump is that it does not have a flange that includes bolt holes. It's mounted using oversized washers.

WWYD? Pump #1 and deal with the tubes or repl pump and deal with grease point issue. Thank you for reading.
 

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