Water pump identification

[Cadman-iac]

  I'm trying to figure out what years these water pumps are supposed to be. I have 7 of them, all are the design for the 331, 365, and the 390. There are small differences between some, but I'm not familiar with the peculiarities of each year.
Can anyone help me out with this?
Thanks for whatever assistance you can provide.

Rick

[Cadman-iac]

Pump number 1, preliminary IDENTIFICATION, '58-'62




Pump number 2, preliminary IDENTIFICATION, '58-'62




Pump number 3, preliminary IDENTIFICATION, '58-62




All 3 of these seem to be the same. And they all have a really thick hub for the fan to bolt to. They're about 1/2" thick. The first two have the same casting number, the third one is a different number.  They all have two threaded holes for a heater hose on the back.

[Cadman-iac]

Pump number 4, "IDENTIFIED" as '54-'56




Pump number 5, IDENTIFIED as a 1956






Pump number 6, IDENTIFIED as '54-'56, possibly for a series 75 or 86.






These 3 pumps appear to be the same except that pump 6 also has 2 extra threaded holes in the upper water passage. They all have a thinner hub thickness as well, more like what you would have on a small block Chevy.
These each have one outlet just above where the lower hose connects, and one just below the thermostat on the back that comes out at an angle towards the right side.

[Cadman-iac]

Pump number 7, preliminary IDENTIFICATION, possibly '49-'53?




This pump has only one threaded hole for a heater hose just above the lower radiator hose. The hub is also the thinner one.

[Lexi]

Hi Rick. It is difficult to say as for the most part, the figures shown don't appear to be part #s but casting numbers. I believe the blue one bearing number "1484403" is for a 1956 Cadillac. While I had some trouble making out the numbers due to casting clarity and the effect of shadows which can distort the image, if that is the number then it matches what is on my car. Hope this helps, somewhat. Clay/Lexi

[Cadman-iac]

  I kind of suspected that. Pump number 5 has another cast number on the upper water passage of "C56", which I took to be for a 56 Cadillac. But I figured I'd just double check that. I didn't want to assume that's what it was and find out later I was wrong.
 Thanks for the verification.

 I was hoping that the heater hose nipple outlet locations and direction they pointed would help pin down what year they are.
 I've seen other threads where someone was asking about that specifically, so I figured that was the key.
 The one with the extra two holes pointing upwards in the upper water passage I would think would be easier to figure out. Of the 7, it's the only one with those.
 Anyone else have any ideas about this?

  Rick

[Cadman-iac]

Those first 3 pumps have two heater outlets/nipples on the back. The one on the right side points straight back towards the intake manifold, and the one on the left side points to the left side of the engine and looks to run parallel with the upper water passage.
You can see it best on pump number 3.
 These are also the only ones that have the extra thick fan hub. I don't know why they made those so thick, except maybe for air conditioning with a bigger fan blade?

[Cadman-iac]

 So pumps 4 and 5 are identified as being for a 1956 365.
 Pump 6 could possibly be as well, but I'm thinking maybe it's for a 57 because of the extra outlets in the upper water passage. Maybe those are for sending units or something?

[Lexi]

As far as I know the '56 pumps have that very large dual brass and steel fitting on the pump's LH side, (driver's side). Think it is for heater core flow, but not 100% on that. Fairly certain they are not on earlier pumps which have a single smaller, diameter fitting there, (unless AC dictated otherwise perhaps?). Believe I have a rebuilt 1955 pump here with the small fitting style that I believe is OEM. Based on visuals it appears to be a unit that would carry less coolant flow than the dual brass/steel fitting I described on the '56, as a smaller inner diameter and only one outlet. The 1956 pumps that I have seen also have "C56" cast into the upper galley arm, LH side. My '55 (going from memory) has "C55" cast there instead. Perhaps that denotes Cadillac as well as the respective year? If you have identical pumps except they lack those C55 and C56 casting numbers, perhaps they were earmarked for other GM products? Does anyone know if there is a manual that identifies casting numbers for such parts? I think once I saw a post that listed either engine block or cylinder head casting information, but not sure where that was sourced. Clay/Lexi

[Caddyholic]

I think 57 Pumps have the lower radiator hose on the oppsite side of the engine. One year only.
The pumps with the extra pipe fittings are for series 75 and cc. and maybe after market (universal fits?)

[David King (kz78hy)]

I have a 1464408 on my '55.  The  plugged tapped hole (on the back of the blue pump) is for the transmission cooler/heater line on cars equipped with the transmission cooler/heater.  Cadillac part numbers starting with 146 were created around 1953 for use on '54 cars.  Most of '58 Brougham has 146 part numbers, but the majority on that car are carry over '57 Brougham parts.

Note:  the plugged tapped hole is for the heater flow inlet on the ranco valve.

[Lexi]

Here are a couple of shots of what I believe is my 1955 Cadillac water pump. It bears casting number #1482531". Note the small port (possible return line) bottom LH portion of image #1. The upper casting identifier (image 2) shows "C55". Again, is this an identifier for Cadillac 1955? My 1956 pump says "C56". I know that this will fit my '56 as it was rebuilt for installation on my car until it was noticed that it had the small return port. As '56s were known for running hot, I thought it better to keep the larger inner diameter return ported pump unit on my car. As for those models in 1956 being only outfitted with the larger port being on S75 and Commercial cars, I am not sure. In a recent, related post, a knowlegeable CLC member with a '56 Caddy commented on this fitting and implied his vehicle had the same, (although I am certain that his car is a Series 62). Long story short, I don't know if only the S75s & Commercials had water pumps with the larger "return" fitting. The OP in the aforementioned thread also has a '56 but did not mention what Series his car is. Law of averages would suggest it was probably also a S62. That said, after nearly 70 years with repairs and parts being swapped out, who knows if their water pump is what really came with their car originally? My last image (#3) is a shot of the larger spare port discussed, from my collection. Clay/Lexi

[Lexi]

Interesting points by David on those parts numbers. Further to my above post, the 1956 Cadillac Master Parts List notes that "Water Pump Complete" for 1949 - 1955 Cadillac cars, are the same unit.  "When exhausted use" ...the 1956 pump. That said, there was a notation that for 1954 cars with AC to also order a nipple and tee (2 different part numbers). 1955 not mentioned in this upgrade. For 1956, model years 1949 - 1956 again quoted with only the mention of "Less pulley" and on AC cars to "...remove fan hub from shaft". This is probably because AC equipped cars came with a triple pulley unit for the extra fan belt (to run the AC compressor). Also, longer connecting bolts used. Both OEM 4 bladed as well as the secret warranty 6 bladed hub fans will fit, speaking from experience. There is no mention of the need to order a different "nipple and tee" for 1956 AC equipped cars, so I would assume all pumps came with the same attachments (except the AC vs non-AC fan hub).  This is the new part number said to replace the 1949 - 1955 water pump part number when exhausted.  So aside from a botcher getting at your car and putting God only knows what on your engine, it sounds reasonable that some pre-1956 Cadillac cars may have been fitted with the 1956 pump either in (late?) 1955 or even earlier models when serviced for a cooling issue and the water pump was changed.  I did not note any special considertation for S75 or Commericial cars. That said, with all of the extra length of heater hose that run to the rear seat heaters (if so equipped), may have called for some change? Perhaps in their somewhere, but did not see it at the time of writing. There are some notations in the Accessories section (AC) that may challenge some of this, though I am a little embarrassed to say that I am not sure what exact parts they were refering to. Hope some of this makes sense.    Clay/Lexi

[David King (kz78hy)]

Lexi,

Your 3rd photo is the fitting for the trans cooler that goes to the heater core and trans cooler.  A special part/fitting.

[Lexi]

That makes sense David. Just not sure if output or return, any idea? What do you think? The MPL seems to say all '56 water pumps came with it. Does your water pump have this fitting? Clay/Lexi

[Cadman-iac]

Okay!!! Clay, David, Caddyholic, thank you all for the information on these. I'm definitely kornfused now!!

First off, Clay, I believe that double fitting you show would almost have to go on the inlet side of the water pump just because of it's size. Right above the lower hose, but I'm just guessing here. The reason I think this is because of the limited space behind the pump/thermostat area.

David, the extra outlet holes in the upper water passage you think are for a series 75 limo and/or a commercial chassis. What would they allow for, extra heaters for the rear compartment?
That makes sense. I guess these would be nice too for someone wanting to add a mechanical gauge or an electrical temp sensor for a backup gauge.

Caddyholic, I looked at my service manual for a 57, and you are right, the 57 lower hose connects on the right side. So I can rule out that year for any of these.

  About those thicker hubs, why would some have that? Does it move the pulley out farther if you don't have A/C?

 Rick

[Cadman-iac]

Some differences between pumps 1-3 and pumps 4-6.

Pumps 1-3 have no heater return inlet just above the lower radiator hose connection.


Pumps 4-6 have a heater return port above the lower radiator hose.


On pumps 1-3 the heater return port is below the thermostat but not in that passage. It has a separate passage that you can see from the front of the pump. My cane is pointing to it.


On pumps 4-6, that front passage is not there, as my cane indicates the spot.


On pumps 1-3 the heater inlet port is indicated here, below the thermostat on the right side of the pump.


On pumps 1-3 the heater supply port is below the thermostat on the left side and is connected to the upper water passage as indicated.


For pumps 4-6, the heater supply port is still below the thermostat but on the right side and points off to the rear at an angle, as indicated by my cane. On this particular pump, the fitting has been removed, but you can still see the port.


Here's a shot of both types hub-to-hub for comparison. 1-3 all have the thick hub, and 4-6 all have the thinner hub.


On the hubs, the only thing that I can see is that it was reshaped for the 4-6 pumps, because the leading edge of each is the same distance from the pump. The thinner one just has a taper to the back side.

Rick

[Caddyholic]

I am 99% sure the thicker flange is a AC car pump. It is on a 61-62 

[Lexi]

Interesting Cadman-iac. Seems that no special consideration was given to S75 or Commercial cars as far as I can see, at least for 1956. No mention of rear seat heaters impacting this either, but would have to dig more to be sure.

The MPL notes that Cadillac water pumps were the same from 1948 - 1955, with the 1956 unit being used when older parts were "exhausted", for servicing older Cads as required. There are some replacement parts noted in the Automatic Heating Section of the MPL, but sadly no comprehensive diagram. Section 6 implied that the 1956 pump was installed/replaced as a "complete" unit. Can't say for sure that I found a listing for that large fitting though for 1956. But there is a notation in the Automatic Heating Section that COULD be it. Perhaps it was required for cars ordered with heaters as the 1956 Cadillac Data Book lists the "Cadillac Heating System" under optional equipment. Lots of cars were ordered with heaters, so perhaps your "C56" was one of those sold in an arid state where a heater was not ordered so no extra fitting on the pump? The abundance of heaters in our cars may explain why so many '56 water pumps have that large fitting? Reasoned speculation as the Data Books goes to some length to explain that the system was re-designed for better circulation (enlarged water passages and other items noted).

So if we accept the 1484403 casting number as being from 1956, (I think OEM on my car) with "C56" perhaps being another identifier for that year, you appear to have 2 1956 Cadillac water pumps, one equipped with the large fitting and one without, as possibly explained by my Heater accessory notation above. Two down and how many to go? Have to ponder your other questions, but Caddyholic's comment on those hubs seems reasonable as the triple grooved AC pulley is heavy cast iron while the double belt style for non-AC cars is lighter weight stamped metal. Perhaps the added weight of the triple groove pulley required a more substantial mounting flange? Clay/Lexi

[Cadman-iac]

Now to throw a wrench into the works, I went out and checked each of my cars to see what was on them, as they are all different, thus my kornfusion with all this.

This is what is on my 55 parts car. It's the same as pumps 4-6, but it also has the extra ports on the top passage like pump 6. I wasn't able to get a good shot from the front because I have parts sitting in front of the car, but you can see the ports in these shots.
This is the heater supply port. And one of the extra ports is visible.
 Preliminary IDENTIFICATION, '54-'56 , series 75, 86?


The heater inlet port, or return port I guess would be the correct term.


It doesn't have any casting numbers, but it does have a number stamped on the front, 30221. It also has the thinner hub.


The pump on the engine I got with the 56 CDV that turned out to be a 62 390 is the same as pumps 1-3. Except that it has the heater return port above the lower radiator hose, and the one just below the thermostat,with the passage visible from the front, but the heater supply port is still below the thermostat on the left side. It's like a universal pump that works for both of the other types of pumps. The return port just above the lower radiator hose connection is more squared off and even with the two bolts that mount it there. The other pumps sit at a slight upward angle. Very strange!
 Preliminary IDENTIFICATION, '62?


On my 56 SDV parts car with the original engine still in it, it has this pump. It's the same design as pump 7 in my first post, but it also has the extra ports on the top passage.
 Preliminary IDENTIFICATION, '49-'53 series 75, 86?


As you can see the heater return port above the lower hose is at an upward angle.
This and the two ports on top are all it has. There are no ports below the thermostat.


The top ports are used, but is this correct?


So with 10 water pumps in my collection, and probably 6 distinct differences between them, I have absolutely no idea which fits what.

Rick