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Water pump packing


Matt Harwood

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I have a water pump that's very leaky. I think this image asks the question better than words can:

 

WaterPump1.thumb.jpg.13edde774b31bf28ba00bbd62c9f82c8.jpg

 

I've never done packing on a water pump before, but I ordered some 1/8" graphite packing material from Restoration Supply. Right now, the pump is leaking significantly enough that I expect the cooling system to be empty by morning. Thoughts?

 

Thanks!

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 You are correct about adding packing material.  Using calipers, measure diameter.  Multiple by 3.14.  You will need to back the nut out.

Cut the length at a 45 degree angle and install by lapping the cut to assure full thickness packing. 

It's not hard to do but can be tricky if you have never done it before simply because it's tight.  Not trying to give an idiot lesson.

 

I personally prefer Teflon packing.

 

 

 

 

 

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If the shaft has irregularities in it from the packings over the years you can pack it every day and it won't help.

Over the years we overhauled many irrigation pumps.

Plain old gray, graphited, braided packing has been the gold standard for packings for a very long time.

 

 

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If what's left seems soft(ish) it's probably OK to leave it.

On the other hand some water pumps use a lantern ring between two stacks of packings for lubrication in which case it would be best to start over.

By removing the existing packings you'll get an idea of the condition of the shaft.

lantern ring.jpg

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34 minutes ago, Matt Harwood said:

Should I remove any leftover packing that's in there?

Yes. And it is normal to put in three pieces, each equal to one circumference. That makes it hard to get the nut on. It can be easier to put one in, compress it with the nut, then the second, compress it with the nut, then the third and do up the nut just enough to stop the drip. As above, the shaft must be smooth.

 

Make sure you keep that graphite cord lubricated so it doesn't promote rust in the shaft when its lubricant dries out.

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FWIW, I agree with Spinney, especially about compressing one ring before adding the next, but suggest using a little water pump grease on the shaft before adding the first circle of packing.  EVERY Old Car Person needs this experience!  And carry some extra packing and a little w/p grease in the car.  I use a film canister (remember those?) inside a small ziplock bag for the grease.  Film canisters are also handy for hiding parking meter change from prospective thieves, but I'm expecting to find them in antique shops any day now. Turn down the gland nut only barely enough to stop dripping, then again a few miles later when it starts to drip.  After three of these minimalist moves, you're set for a few thousand miles.

 

PLEASE remove the grease fitting and install a (turn-down) grease CUP.  The fitting is ONLY for use with the T-handle short grease gun that came with the car and which applies very low pressure compared to a lever-handle grease gun--the latter will blow your seals.

 

It's worth trying the original materials and techniques.  If your pump remains a leaker, it will probably need a rebuild including a new shaft, at which time it's best to use modern seals and sealed bearings instead of bushings--zero maintenance.

 

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I think you should let it leak a tiny bit. Big irrigation pumps are ALWAYS left to drip a little, any tighter and it will burn up the packing and the shaft. I have always done the same with cars, and somehow I rarely seem to have much trouble.

 

A tiny drip is all it takes. It is kind of hard to see on my Pontiac, but I think I get a drop every 10 or 15 minutes. It always feels wet if I put my finger down there, but no antifreeze ever hits the ground.

Edited by Bloo (see edit history)
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You have to get the shaft right first.   That is the essential starting point.        Dismantle the water pump, and accurately measure what it should be.     Take Photographs so I can see where keyways and woodruff keys go.

Also I need to know  size and placement of any thread,   You need to give me enough information so I can make you a new shaft out of something like 4140 steel.    Then what I do is reduce the diameter slightly, build up the section which runs inside the pump with a Metco stainless steel coating.  I use an air-hardening phenolic sealer, because the coating is a coalescence of millions of molten droplets on the shaft.  Then I grind it between centres to the correct size.  The ground finish is very smooth, yet has miniscule pits in the ground surface which I generally wipe over with a suitable Teflon grease.    I rebuilt the water pump shaft of a 1920s Rolls Royce Silver Ghost.   I gave my friend instructions where to buy new packing, and how to cut and fit it.     A couple of years later I saw Des at a swap meet: he told me that the pump leaked  just an occasionally on the ground when it was standing,   It turned out that Des had forgotten to buy packing form the farm store, and had forgotten to instruct anyone to fit the packing.    The new shaft I shall make and post to you will be better and last far longer than a new original shaft, and it will cost you nothing.  It is for goodwill.     Some people make this type of water pump shaft out of stainless steel, and that  gets hot.    Regards......

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Thanks for all the advice. I'm going to try the packing before I tear it apart to replace the shaft. It was holding and working until the generator was removed to be rebuilt so I'm hoping that the packing was just shot. I ordered the 1/8" graphite packing from Restoration Supply, and on the advice above, I'm going to also order a proper grease cup and some water pump grease from the same place this week. I'd like to do it right. I'm optimistic that I can get it sealed up and working right.

 

I'm betting that when I get to the shop tomorrow morning, the cooling system will have pretty much drained itself into the pan I put under it (although the engine holds 8 gallons and my pan was only 5). Instead of instantly refilling it I'm going to fix the packing, get the system sealed up, then fill it with some dilute Evapo-rust and let that circulate in there for a few days. I'll add the sock filter Grimy recommended as well to catch all the trash. Hopefully those steps will help it run a little cooler. I might back-flush it after the Evapo-Rust, too. Can't hurt.

 

I note that the radiator shutters seem to be working, but the hood vents are also thermostatically controlled and it appears that someone tried to permanently fix them in the open position, so I'll look into that, but obviously open is good. 

 

Anyway, it's just waiting for parts now. Hopefully before Wednesday so I can work all day Wednesday, but if not, it'll have to wait until next weekend. I have a few other tasks I want to get done before I take it to a CCCA Grand Classic on the 14th.

 

Thanks again!

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13 hours ago, autoluke said:

Matt

 

Your mention of thermostatically controlled hood vents has caught my attention.

 

Exactly what are you working on ?

 

Phil

 

1935 Lincoln K. The radiator has the usual shutters controlled by a thermostat, but it also has a thermostat on each hood side that controls the vents there as well. I have not driven my car enough to know whether they work, but they seem to have springs attached to them designed to hold them open and when they're removed, the shutters are a little floppy. My guess is that the thermostats controlling the hood shutters are inop since they seem to be mostly open all of the time. Here's a page from the manual describing it (with a helpful diagram!).

 

ManualPage1.thumb.jpg.bac1e587f01f8d1c55526f06c139159d.jpg

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The water pump graphite cord showed up today and I'm getting ready to try to seal it up. Just to confirm, the best way is to cut small lengths that match the circumference of the water pump shaft? I've seen others do it by simply winding the graphite string around the shaft a few times then reinstalling the packing. Would that be incorrect? 

 

What is the best way to maximize my chances of success?


Thanks!

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In a perfect world you would do it EXACTLY like Friartuck's illustration. I always had the angle cut and overlap 90 degrees from the way he did it, but I doubt it makes much difference and thinking about it now, his way might be slightly better.

 

That assumes that you have the right size packing, and since you didn't take it apart ahead of time, I doubt it. If you can't do it Friartuck's way, then dig anything out that is hard and rocklike (or dig it all out),, and cram some packing in there any way you can. You don't want one layer with a square cut if you can help it. Multiple layers, even if you have to cut up the packing to do it, or you just might have to wind it around there if the packing is way too small. Take Spineyhills advice and don't try to get it all in at once.

 

Be nice to the shaft. Put some water pump grease on it. Final adjustment should still have a slow drip.

 

 

Edited by Bloo (see edit history)
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Thanks, Bloo. I have 1/8" square graphite packing, which looks like what came out of there (although there was virtually none left. Shaft looks clean and not pitted. We're going to try to use Friartuck's technique and see how it goes. My fingers tend to fumble when it's that small, but using some water pump grease (which I also purchased) should act as a bit of an adhesive to keep it in place. If I fail two or three times, then I might resort to the spiral technique, but that will only be out of frustration. I want to get this right.

 

Thanks for the quick feedback--I'm off the workshop!

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Yep. That is it. Sharpen your fingers. LoL! One circle at a time, then push in with the nut. This is an exercise in frustration breeding (im)patience. Your back will not be thanking you for spending an hour leaning in there either.

 

Enjoy your day!

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So what's the math, because obviously I'm failing. I went from ready to work to "screw this" in about 15 minutes.

 

My calipers say the shaft is 15mm in diameter (I'm using millimeters to make the math and measuring easy--1.65 inches isn't so easy to find on a ruler). The formula for circumference is diameter x pi, or 15mm times 3.1415, which is about 48mm. So I cut a 50mm chunk and figure I'll trim it and sneak up on a perfect fit. Unfortunately, the 50mm piece is about 10mm too short. What am I doing wrong? I'm good at math, but something's not adding up and I'm pretty close to just wrapping it around the shaft a few times and cranking the hell out of the nut and living with the leak. 

 

15mm x 3.1415 = 47.8mm. A 50mm long piece of packing doesn't even come close to wrapping all the way around the shaft. Where am I going wrong?

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Not quite 3/4 inch. Look at the picture up there. Almost the same diameter as my pinky finger. Math still doesn't add up. I can't wrap the piece around my finger any more than I can wrap it around the shaft. A 60mm piece fits, which is what I'll use when I have more patience, but that would suggest a 20mm shaft, which this is not. I'm not happy about the math being screwed up and having to guess at the right size and somehow shove it in there with a pair of needles. AND get the gaps offset? AND make sure the packing doesn't twist as it goes past the threads? AND make sure that I can fit three loops in there? 

 

How could anyone afford to service these in the past? Two guys need four days to install three pieces of string.

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I agree with Wheelmang. 15 mm is .591" diameter. That is both strange and small (if it is a USA car).

Friartucks method is the correct way to pack a pump. Take the time, do it right and you wont be back working on it again.

One of the faults with just wrapping the packing is that at the beginning and end, you end up with a step of the packings size. Makes it harder to seal and compress.

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I believe you should be measuring and calculating using the  diameter of the outside of the space, not the inside or shaft diameter.  Also if you are cutting on a diagonal you must allow for that extra length.

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So here's my caliper at 0 (yes, it's a crappy caliper--someone broke my nice one).

Caliper1.thumb.jpg.61877566099d4127a3354855a93da684.jpg

 

Here's the caliper on the shaft measuring diameter. That shows 15mm (or a little under 5/8 inches) no?

Caliper2.thumb.jpg.e054b005e176a35c38506d8763c1b8fb.jpg

 

Here's my pinky finger near the shaft for perspective.

Finger1.thumb.jpg.4ead01967a47fec9ba875ea480cefeef.jpg

 

All this is academic. I can figure out how long to make the thing. But I'm still struggling with how to get it to stay in a circle while I wrap it around the shaft and somehow shove it into the pump housing. Needles of some kind? Tweezers? There's no way my fingers are fitting in there, and I don't even have particularly big fingers. I even had my wife and her little fingers try it and no dice. What's the trick? I'm frustrated so I'm quitting for the day, but I have to try again tomorrow and I'd like to have a plan of attack.


Thank you for the feedback, it's appreciated. Sorry I'm grumpy. At least nothing got thrown or broken today...

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Um, if you are using 1/8" packing rope, perhaps the diameter you want is shaft diameter + half rope thickness + half rope thickness = 15.5+3.2 = 18.7 mm or a spot under 3/4". That is, the inside of the rope will be against the shaft and the outside will be too short because it hasn't stretched. So use the diameter to the centre fibre of the rope.

 

18.7 x pi = 59 mm. Might that work?

 

I just twigged - referring to structural engineering in my past. In bending (e.g. a beam), it is assumed plane sections remain plane.

Edited by Spinneyhill (see edit history)
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Remember that the calc on the SHAFT circumference is the ID of the packing.  You'll need to factor the packing thickness. and if you cut it on a 45, add another roughly 5mm (sqrt 2 times packing thickness).  As Mr FriarTuck said, cut it on a angle and attempt to get three sections in.  It'll be tough.  It will take some time and you most likely will have several failed attempts.  With the first ring on, push it in, then add the second ring - tighten.  add the third ring.

Upon success, you will have a good feeling.

 

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What do you guys think of these instead?

 

A-8524-L-730.jpg

 

https://www.snydersantiqueauto.com/water-pump-packing

 

Those are lead-based rings specifically for water pump packing and the Model A guys over at Ford Barn say that's the very best choice. They're for a Model A, and since the Model A and the Lincoln are both Ford Motor Co., perhaps they would be compatible? Model A water pump shafts are .625 inches, and that's about what the Lincoln's shaft is, if I'm measuring correctly (and I think I am). Snyder's is local-ish to me and I bet I could go out there and get a bunch of those rings and have them in the car by lunch. 


Thoughts?

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