Water pump fitment

Jim Van

Jim Van

Joined
Sep 10, 2011
Messages
2,199
Location
West Michigan
Bike
'98 ST1100
Does anyone know if there is a physical difference between a water pump for a '93 and '98 ST1100 water pump ? Will a pump off a '93 fit a '98 ?

I know the part numbers are different, but what is the diff ? They look the same on the finche.
 
Can't answer that impromptu without actually seeing the parts...
They do have different P/N, so its to be assumed that they actually are different in some way:

'93: 19200-MY3-010
'98: 19200-MAJ-G20

It does not seem to be the case vent (like on the very early models), since the P/N for the breather hose is identical, also both O-rings (mains and breather) and all bolts are identical...

So I assume(!) that the difference is only "internal", changed design/maker of the shaft seal, other alloys being used, as simple as a different vendor, or all of above...

Wait for others to chime in, but IMHO the chances of interchangeability are good...
 
ST1100Y ; That's my feeling too, but I needed some feedback from others. Thanks !!

Waiting to hear from John O. and Uncle Phil .
 
Short answer: the 93 water pump has a port for the hose to the oil cooler. The 98 doesn't have the cooler so it's pump doesn't have the port/hose nipple. I wouldn't try to plug a 93's and install on a 98.

John
 
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Thanks John. I knew you would know the difference, if any.

Darn, I heard something about that before, but it's not apparent on the parts diagram.

So, it looks like I'm looking for a '95 or later pump that someone has laying around that may want to donate to me so I can have the Dutchman rebuild it.

Then I'll report back to the Forum what I think of the work.
 
Jim Van said:
Thanks John. I knew you would know the difference, if any.

Darn, I heard something about that before, but it's not apparent on the parts diagram.

So, it looks like I'm looking for a '95 or later pump that someone has laying around that may want to donate to me so I can have the Dutchman rebuild it.

Then I'll report back to the Forum what I think of the work.
Click to expand...

yeah, the fiche appears to have a generic water pump diagram, that can't be taken literally. I have a '97 pump, but it has rusted impeller blades, so you wouldn't be able to re-use the impeller. If you can swap a good impeller into it then it might work for you. Determining if the older/newer units have the same impeller would be your next step.
 
FWIW FYI - The oil cooler can be removed from 92-95 ST1100s and the later models' water pump installed. The Water Pipe and the threaded pipe/plug that the oil filter screws onto are replaced.

John
via iPhone 6
 
John OoSTerhuis said:
The oil cooler can be removed from 92-95 ST1100s and the later models' water pump installed.
Click to expand...
I recommend that only when also having the air-cooled 40A alternator installed!
The necessity for the pre '95 heat exchanger filter base was due the oil-cooled 26A unit... which I believe all you 'Merricans have removed by now... ;-)
 
Hey Jim,

I got your PM and called the Dutchman. He said he could check with his source to see if a replacement impeller was available, but he didn't think it was very likely they'd have one. He also said a typical rebuild job for that pump would cost $165 plus shipping if the impeller was good to begin with. A new impeller would add another $15 or so, which puts the rebuild job around $200 with shipping. Doesn't seem like enough savings to be worth it, don't you think? Probably a moot point anyway, since he didn't sound very confident about being able to replace the impeller in the first place.
 
ST1100Y said:
For $290,- you'll get a brand new one to slap in and forget for another >100K...
Click to expand...

even less than that, Western Honda has them for $259. Haven't looked around to see who is the absolute lowest.
 
dwalby said:
Hey Jim,

I got your PM and called the Dutchman. He said he could check with his source to see if a replacement impeller was available, but he didn't think it was very likely they'd have one. He also said a typical rebuild job for that pump would cost $165 plus shipping if the impeller was good to begin with. A new impeller would add another $15 or so, which puts the rebuild job around $200 with shipping. Doesn't seem like enough savings to be worth it, don't you think? Probably a moot point anyway, since he didn't sound very confident about being able to replace the impeller in the first place.
Click to expand...

Dwalby: Thanks for making the call to the Dutchman. A few months back, he gave me a quote of around $115. But even $180 sounds good compared to $259 - that's a $79 savings. The Dutchman's pump is just as good or better than new. Nothing magic about a new pump. I believe the pump is made by Keihin and I'm pretty sure they make pumps for Honda cars too. So the impeller may be available.

EDIT : Just read a few blurbs on the internet and watched a guy on YouTube rebuild a water pump. It's a fairly easy task to do. Plan B would be for me to rebuild the pump myself. The bearings and seals should be easy to source and I bet the impeller won't be that tough to find, either. EDIT : In fact, there is a new improved seal design that is used now that is probably better than the OEM seal.

ST1100 Water Pump.jpg
ST1100 pump

85 Civic Water pump.jpg
Honda Civic Pump

Notice the similarity of the impellers ??
 
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Jim Van said:
Dwalby: Thanks for making the call to the Dutchman. A few months back, he gave me a quote of around $115. But even $180 sounds good compared to $259 - that's a $79 savings. The Dutchman's pump is just as good or better than new. Nothing magic about a new pump. I believe the pump is made by Keihin and I'm pretty sure they make pumps for Honda cars too. So the impeller may be available.

EDIT : Just read a few blurbs on the internet about rebuilding water pumps. It's a fairly easy task to do. Plan B would be for me to rebuild the pump myself. The bearings and seals should be easy to source and I bet the impeller won't be that tough to find, either.
Click to expand...

Hmmm, maybe he saw my Calif area code on his caller ID and jacked up the price:D I think he also mentioned the main bearing was about a $40 part. Maybe he's learned something over the last few months and it requires more work than he first thought, or the parts cost is higher than he first thought. Ron Ayers has the pump for $238.83, that's the only other one I checked, it seems like a pretty good price. Not sure if they offer free shipping, but if so then you have to add two-way shipping to Oregon into the rebuild cost comparison. I don't see how its worth it to have him rebuild it for you, the savings just don't add up to all that much, and its a mission critical part if it fails. With a new factory pump you at least have an idea of its expected longevity, with a rebuild who knows? If you have the ability to rebuild it yourself, then your savings are more substantial, and you'll know how well the rebuild job went and can gauge the confidence level of your own work.
 
UPDATE :

Did some research / digging and dwalby sent me his old water pump for me to play with. I also took a chance and ordered a new Gates water pump for a '85 1.3 liter Honda Civic from Rock Auto ( $24 w/shipping). The pump that is pictured in my previous post is an Airtex pump. It has a stamped steel impeller. From what I have gleaned from the internet recently, the cast iron impeller in the Gates is superior.

I'm happy to report that the shaft / bearings are a match between the ST1100 and Gates pumps. I have the part number off the ST1100 shaft.

The cast iron impeller from the Civic almost fits .... it's about 0.13 " too large in diameter. But it can be quickly and easily turned down in a lathe.

When disassembling the Gates donor pump, the seal may be damaged because it's pressed onto the shaft. This is a superior design. The original ST1100 seal ceramic "ring" is pressed into the recess in the back of the impeller. But I wouldn't want to take a chance and reuse the seal out of the donor pump.

So, at this point, I am getting prices for the bearings / shaft, seal, cast iron impeller, and seal installation tool from a water pump rebuilder that I found on the internet that also sells parts. BTW, When they talk about "water pump bearings" , that means the bearing and shaft assembly. Then I will be able to determine the cheapest way to get the parts needed; getting all the parts from the supplier, or getting a donor pump and only the seal from the supplier. I'll report back when I get that info.

The actual rebuilding I think is a fairly easy job ( with a press and the right pullers and tools ).
 
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Do you want the pump off my 1997 ST?
For shipping cost you can have it to play with. If it is worth anything, you can pay me 1/2 what it is worth (and not more than $50) if it works for you. If it's worth nothing, it cost you nothing more.
The bike and pump were working fine when I shut it down 8 years ago but it had 137,000 miles on it and I haven't had it apart. It will probably fit in a $12.60 USPS express package.

Later,
Kent Larson in Minnesota
 
mudduc said:
Do you want the pump off my 1997 ST?
For shipping cost you can have it to play with. If it is worth anything, you can pay me 1/2 what it is worth (and not more than $50) if it works for you. If it's worth nothing, it cost you nothing more.
The bike and pump were working fine when I shut it down 8 years ago but it had 137,000 miles on it and I haven't had it apart. It will probably fit in a $12.60 USPS express package.

Later,
Kent Larson in Minnesota
Click to expand...

Thanks for the offer Kent, but I don't know what I would do with another pump since dwalby already sent me his old pump.

My goal is to save a few $$ for myself and Forum members too by rebuilding their pumps instead of needing to purchase a new pump.

UPDATE : I haven't heard back from the supplier by email yet, but I found a limited source for the seals on EBay. I have three seals on the way. So after I receive them and after I get the cast impeller turned down 0.13 " , I'll be ready to rebuild the pump dwalby sent me.

It will be about 2 years / 20 K miles until I'm ready to replace mine ( or sooner if it goes south before then ).
 
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