remove pump off engine inquiry

sgull

Member
I acquired an old 1960 era WS Darley portable fire pump. The pump is on the PTO end of the engine shaft (Briggs & Stratton model 23A). I'm wanting to remove/separate the pump from the engine, so I can feel free to test run the engine (without having to worry about running the pump while it's dry) during my attempts to get the engine into good operating condition before eventually reinstalling the pump and actually using it to pump water. I've removed the pump casing so far, but am unclear how I'd probably proceed to remove/separate the pump from the engine shaft. I've checked with the Darley company already and they say they don't have any assembly/disassembly drawings/diagrams or such for the old model pump. I'm hoping I might get some guidance/advice from forum members here in that regard.

Here's a picture of the pump, still with its casing, on the engine.

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I removed the four bolts (pointing to one of them in the picture below) that holds the pump coupling to the engine. With those removed, the coupling will turn easily but of course does not pull out/away from the engine:

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I removed the pump casing (as seen below) which exposes pump business inside:

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Below is a couple shots of it:

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I'm guessing to get the pump off I'll be needing to remove this nut (shown below) somehow first. But again, that's just my guess. If I do need to remove this nut, I don't know how I'd go about it. It's got those lock metal pieces all around through it. I don't know what those are or how to get to them to remove them. Any comments appreciated.

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That lools like a regular lock nut to me. Just soak it up good with PB Blaster or something and I'd use an impact wrench. Be careful to find out if its right or left handed threads. Should come right off.
 
That nut is called a Castle Nut. Unless there is a cotter pin thru the slots on the end, it should just unscrew like a normal nut. Use an impact wrench if you have one and lube the threads. The parts are probably rusted on the shaft. It looks like the housing next to the engine should just slide away. Might try tapping the casing away from the engine. I would expect to find a square keyway with key on the end of the engine shaft.
 
Okay, thanks for the replies. Yeah okay a castle nut. I've seen/heard of those in the past but really haven't had much in the way of experience using/dealing with them. I'm fairly certain I saw no cotter pin there on the nut. I'll try to find out for certain whether it's gonna be left handed or right handed thread, shoot some PB Blaster and let it soak a good while, then proceed to try to remove the nut then. I don't happen to have an impact wrench. I'll probably need to figure out a good way to hold the the shaft from spinning while I try to remove the nut. So, just remove that castle nut like a regular nut? I'll have to admit I don't really think I've seen a castle nut that appears like that before, with the metal wedge protrusions like that. The ones I've seen/used are the open slots all around through which you can insert a cotter pin. Maybe that's what this one is too, but I dunno just somehow looks different to me. Also, if there is no cotter pin, I wonder why the castle nut was used in the first place? Does it "lock" better than a regular nut would, even without cotter pin?
 
It's possible someone used a steel cotter pin and it's rusted away. Or that was the only stainless nut they had, so they used it. Check the thread, I don't think it would be left thread, but better safe than sorry!

Once you get the impeller off, and it should slip off, be on a keyed shaft, there will be a spring and a mechanical seal behind it. This would be a good time to replace it while you're in there. They are available at bearing supply's.
 
I suppose, as suggested, someone used a steel cotter pin and it rusted away or that was the only stainless steel nut they had so they used it. In regard to checking the thread to find out whether its left-handed or not, is there some way I can tell just by looking at it? And, once I do get that nut removed, that's what will loosen/release the impeller? And that should then allow the pump to be removed from the shaft? Or will allow slippage enough to where I can see/access the key on the keyed shaft?
 
hopefully I can attach a picture... but here goes.

You can determine if it's LH or RH threads by looking at the end of the shaft (where the arrow in the picture is pointing) and see which way the thread runs out to the end of the shaft... if is counterclockwise... it's a right hand thread... opposite ? its left hand.

I'd pour the PB blaster or Kroil to it for a day or two and try the nut. You're going to need a strap wrench or something to stick thru the impeller vanes to hold the impeller while you apply pressure to the nut... a trip to Harbor Freight or Craigs list and finding a cheap impact wrench would be worth it (if you have the air) If you attack it with a ratchet and socket start slowly and if you hit resistance... check between the 'spokes' in the nut and look for a rusted or sheared off cotter pin. You'll have to drive it out with a pin punch or drill it out... good luck with that.

Once you get the nut free... more PB Blaster around the shaft and let it seep down between impeller and shaft... Gentle persuasion with a hammer around the perimeter might help break loose the corrosion or rust that probably seized the shaft and impeller. A puller might be needed to get it to break loose.

Be gentle and take your time... it WILL come off with enough PB and persuasion...
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Put those four studs (that hold the pump to the engine) back in and tightened down. Now run the engine---There won't be any "running the pump dry".
 
An electric impact wrench would take that nut off. I have a B&D Industrial electric impact that is real good for that.
 
What is the chance of seeing a close up of the other side of the engine. I have a B & S I think is some version of a model 23 but no blower housing so no positive identification. Thanks in advance. J.
 
Hi you can tell rotation by looking at discharge of pump
or turn motor over. The nut willwant to tighten so you know th
he rotation. Ed will
 
I've been wondering for sure about whether I need to worry about running the engine/pump with no water. I have instructions for a later model similar design portable pump where there are two specific statements that lead me to believe (apparently erroneously?) that I shouldn't.
1. "Never run the pump at any speed without water longer than the short interval required for priming".
2. "Never run the pump at high speed at any time unless it is discharging water".
Further comment in regard to above appreciated!
 
(quoted from post at 15:55:06 01/05/15) What is the chance of seeing a close up of the other side of the engine. I have a B & S I think is some version of a model 23 but no blower housing so no positive identification. Thanks in advance. J.

Yeah if you are John I am wondering did you ever get that picture of the flywheel you asked for and I emailed you? Because you said you were trying to identify a model 23 not . Got no reply.
 
Clearly from the photos the impeller turns counter clockwise when viewed from the pump end. It should be a right-hand threaded nut. I disassembled a similar pump and the impeller was also threaded onto the shaft.
 
Don't run it until You remove that impeller!
That seal behind it is what needs the water for
lubrication.
That castle nut should be right hand thread judging
by the direction of the pump.
Good Luck with Your project.

Steve A W


.
 
I wonder if those metal wedges you speak of between the castellations are some sort of keeper to lock nut on shaft. I would check to see if you can catch the end and pry, drive them down flat before you try to loosen nut. Have seen that before, but usually on a shaft with one flat side.

Dick ND
 

Okay then probably right hand threaded nut, thanks. Not too excited to hear the impeller might also be threaded onto the shaft though.
 

Yeah I wonder about those apparent "metal wedge" looking things on the castellations too. Not sure what you mean by "catch the end" and pry though, to try to drive them down flat. Hopefully these aren't those kind (the kind you mentioned you saw before on a shaft with one flat side), and something like trying to do all that won't be necessary.
 
(quoted from post at 19:09:44 01/05/15) Don't run it until You remove that impeller! That seal behind it is what needs the water for
lubrication. That castle nut should be right hand thread judging
by the direction of the pump.Good Luck with Your project.

Yeah that's what I thought. Can't be running the pump without water. So, at least gotta remove that impeller, but not necessarily the whole pump? Or I suppose that pretty much is the whole pump? Okay castle nut right hand thread, got it. Thanks. And thanks for the good luck wish cause I'll need plenty of it with this business.
 
Unless there is some SENSIBLE reason to disassemble the pump, put what you have taken apart back together, plug the intake, and pour the pump full of water, then play with the engine to your heart's content.

At this point, you are following the philosophy of "if it ain't broke I'm gonna "FIX" it 'til it is"!
 
(quoted from post at 22:36:29 01/05/15) Unless there is some SENSIBLE reason to disassemble the pump, put what you have taken apart back together, plug the intake, and pour the pump full of water, then play with the engine to your heart's content. At this point, you are following the philosophy of "if it ain't broke I'm gonna "FIX" it 'til it is"!

No, believe me, I don't want to be be disassembling the pump unnecessarily.
I appreciate any valid advice/suggestion that will allow me to play with the engine until my heart's content with the pump still attached, but not pumping water. I didn't realize, and wouldn't have thought, that all I'd need to do is plug the intake and pour the pump full of water. Wouldn't it also be necessary to plug the outlet as well, or not? Pardon my ignorance.
 

I'm with Bob. Don't worry about it. Our fire dept. had two of those for many years. They both were started up dry and then an exhaust Venturi primer was used to prime the water up to them. The process was sometimes lengthy due to a leak between suck line lengths. They were always dry to start out and in maybe 25 years we never replaced a seal. if you just have water over the center line of the pump you can run it for hours. Don't worry about it.
 
(quoted from post at 05:47:27 01/06/15)
I'm with Bob. Don't worry about it. Our fire dept. had two of those for many years. They both were started up dry and then an exhaust Venturi primer was used to prime the water up to them. The process was sometimes lengthy due to a leak between suck line lengths. They were always dry to start out and in maybe 25 years we never replaced a seal. if you just have water over the center line of the pump you can run it for hours. Don't worry about it.

Very good to hear.^ I'll just keep some water over the center line of the pump as per the advice, and then[b:3b87010c92] won't worry about it [/b:3b87010c92](much). Mine too happens to have the exhaust Venturi primer as mentioned. I understand those [i:3b87010c92]can[/i:3b87010c92] be rather "tricky" to get the hang of. For some.
 

That makes sense and I could do that too. That'd probably be a little more trouble than just plugging the intake and just pouring the pump full of water (per Bob) and then making sure to keep water over the center line of the pump (per showcrop).
Any comments on which method might be better/best to use?
 
(quoted from post at 09:35:02 01/06/15)
That makes sense and I could do that too. That'd probably be a little more trouble than just plugging the intake and just pouring the pump full of water (per Bob) and then making sure to keep water over the center line of the pump (per showcrop).
Any comments on which method might be better/best to use?

Pumping water with it involves sealing the discharge which would as you say be a little more or maybe a lot more trouble than just maintaining some water in it. The exhaust Venturi actually works pretty nice provided it seals fairly well. Yours doesn't appear to be weathered so the seal point is probably good. By the way your impellor looks very good too.
 
Pumping water with it involves sealing the discharge which would as you say be a little more or maybe a lot more trouble than just maintaining some water in it. The exhaust Venturi actually works pretty nice provided it seals fairly well. Yours doesn't appear to be weathered so the seal point is probably good. By the way your impellor looks very good too.

Very good to hear that about the exhaust Venturi and the impeller. So if I just cap/plug that pump intake and then just fill up the casing with water then I should be good to go? Doesn't that water just immediately exit the discharge though? Also, another thought I have is wouldn't testing the engine this way without an actual "load" of the pump pumping water be inconclusive in that regard? Yep I'll admit it I'm rather clueless. :oops:
 
(quoted from post at 15:58:46 01/06/15)
Pumping water with it involves sealing the discharge which would as you say be a little more or maybe a lot more trouble than just maintaining some water in it. The exhaust Venturi actually works pretty nice provided it seals fairly well. Yours doesn't appear to be weathered so the seal point is probably good. By the way your impellor looks very good too.

Very good to hear that about the exhaust Venturi and the impeller. So if I just cap/plug that pump intake and then just fill up the casing with water then I should be good to go? Doesn't that water just immediately exit the discharge though? Also, another thought I have is wouldn't testing the engine this way without an actual "load" of the pump pumping water be inconclusive in that regard? Yep I'll admit it I'm rather clueless. :oops:

The water wanting to exit is why I suggested just enough to keep it to the center of the shaft. You will be able to check out, tune, and adjust it by running with just enough water in there to keep the seal wet. When you are satisfied with it then you put on the two a half inch suction and discharge hoses and really load it by moving all that it will handle with the discharge valve all the way open. Then you can fine tune the carburetor load adjustment.
 
The water wanting to exit is why I suggested just enough to keep it to the center of the shaft.

In order to fill water up to at least the center of the shaft within the pump casing, it seems I'd need to have the intake plugged/capped off (as previously advised), and then fill the casing with water via the one of the discharge outlets. I surmise then that any water below the level of the center of the shaft will not exit (discharge) with pump operation, and that any water above the center of the shaft will want to exit, correct? Without being able to see the actual level of the water within the pump casing, how do I know for sure or be able to monitor whether I'm definitely maintaining the level at least up to the center of the shaft?

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(quoted from post at 20:42:29 01/06/15)
The water wanting to exit is why I suggested just enough to keep it to the center of the shaft.

In order to fill water up to at least the center of the shaft within the pump casing, it seems I'd need to have the intake plugged/capped off (as previously advised), and then fill the casing with water via the one of the discharge outlets. I surmise then that any water below the level of the center of the shaft will not exit (discharge) with pump operation, and that any water above the center of the shaft will want to exit, correct? Without being able to see the actual level of the water within the pump casing, how do I know for sure or be able to monitor whether I'm definitely maintaining the level at least up to the center of the shaft?









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You are still overthinking this. I didn't recommend closing the intake. I recommended maintains water to the mid point of the impellor. It will want to draw in and push out while running and it will constantly throw water up towards the discharge and it will fall back down due to lack of more water to push it. If I were doing it myself I would use whatever pipe fittings I had, like a nipple and an el to hold a little water there. If I didn't have those I would take duct tape and close the intake off to about 2/3 of the way up and monitor it there. If it has too much water it will be able to push it out. If it has just a little it will just splash around in there, and keep the seal happy.
 
I didn't recommend closing the intake.

Well Bob did say plug the intake and you said you were with Bob on this. I think that threw me off, but with your further elaboration/explanation [b:95191fbc52]I get it now[/b:95191fbc52]. Thanks showcrop for spelling it out for me.

I'm certainly relieved to know I don't even need to remove that pump. Big time thanks to you (and the others here) who've made that point and gotten me off that track.
 

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