I have three water pumps that I would like your assistance to identify. Hoping to find out the specific year and if they would have a bushing or bearing if that is possible. The backing plate of all three looks the same with a single hole so should physically fit on a 1937 216.
1st is marked GM 9 598309 - Year? - Bushing or Bearing? - What is the significance of GM 9 in comparison to a GM 10?
2nd (Green) Looks to be marked GM 838764 Spinsteel - Year? - Bushing or Bearing?
3rd with a different pulley than the other two. Doesn't appear to have been used. Pulley marked with "A" inside an inverted "V". Number mostly concealed under pully but could be something like N0808869 - Manufacturer? - Year? - Bushing or Bearing?
They are all bearing type pumps. To make a long story short the 1937-1940 has ONE hole in the back plate and the 1941-1952 has two large hole. The 1953 and up has an additional small by=pass hole added on the back.
In regards to all three being bearing type pumps, would that be because 1937- 40 pumps would be bearing only or that you know these specific pumps are not bushing types?
Anyone know what specific years the three water pumps are and who might have manufactured the non-GM pump?
As Gene noted, those are all bearing pumps. The original 1937 pump was a bushing type pump but it was replaced by the 598309 sealed bearing pump. You do not have one of those.
The third pump in your list appears to be an aftermarket pump that will work for the 1937 through 1940 applications.
Water Pump story... The original 1937 water pump was the bushing type and had visable oilers, Etc The early 1938 water pump was a slightly improved version of the 1937 pump. In mid 1938 a ball bearing was introduced mid year and used in new vehical production. The casting number on the pump body was 598309 and was sold for replacement on 1937 and 1938 models. The pulley for that pump was stamped 838764. A different off-set fan blade was necessary when that pump was used on 1937 vehicles.
The new ball bearing was used on 1939 and 1940 models, The 1939 and 1940 pulley was stamped 838905 and the 598309 casting number was on the pump body. That pump was a different overall length than thhe late 1938 pump.
Note the number was STAMPED on the pullet so it was sheet metal and not cast iron.
There were probably a dozen different after market water pumps sold that had diferent features
I really appreciate all the information! I've learned a lot about water pumps.
As always, one more question. . . . . Does the fact that the green pump has an oiler pipe mean it has a bushing or did bearing types sometimes have oilers?
Is there a casting part number on the pump body for the green pump? I agree that is a GM pulley on it. Just not sure about the pump itself. It could be an aftermarket part. My '37 had an aftermarket greaseable bearing type pump installed when I got it.
My experience with castings and forgings is that the single numbers are typically used to identify the pattern/cavity in the mold or forging die that produced that raw part. That was done to help back track if there were issues when machining or installing the finished part.
I've searched the green pump thoroughly and there could be a casting number well hidden under the pulley. Feels rough in an area like what you'd expect if there were raised markings but too far under to be sure.
Is this the time to ask what the procedure is for separating the pulley from the pump as you'd do if installing a rebuild kit? Can the average person really rebuild pumps without specialist tools?
You can rebuild the pump following the instructions in the shop manual. Gene is right as always that you need a special puller to remove the pulley. You will break it using a jaw type puller on the flanges.
I made one from a couple of pieces of angle iron. The key is to pull through the 4 threaded holes while pushing on the pump shaft. Others have made pullers from a thicker plate of steel with holes for the bolts and a large hole with a 5/8” nut.
When you push the bearing assembly out you essentially ruin it because you push on the shaft from the back side to remove that whole assembly. That load is transmitted through the bearing races.
Properly support the inside of pump housing when installing the new bearing while pushing on the outside diameter of the bearing assembly. Then you have to support the front end of the shaft when you install the impeller.
I'm starting to think water pump rebuilding is for the advanced mechanic even with a shop manual. If I was to foolishly try because I have three and the green one could be expendable, is the special puller a vintage Chevrolet specific tool or can any modern pump puller from Napa or Harbour Freight do?
I expect that there was a Kent-Moore tool that fit the pulley holes and applied pressure to the shaft.
The people I know who rebuild these pumps have a puller they made.
I doubt if you will find anything at those stores. The bolt holes are very close to the center of the shaft. Plus they are only 1/4” bolts so you need to use all of them when you remove the pulley. Most commercial pullers with legs that accept bolts threaded into holes will not fit that small pattern. And they are not set up for 4 legs.
As I stated earlier you cannot put any pressure on the pulley flange.
You will need a press to separate the water pump parts as Gene has advised.Done this a few times following manual instructions. First you press off the pulley and then you press out the bearing or bushes. An additional job which may improve cooling water flow is to remove the outlet casting from the block and clean the inside of the casting outlet with a 1 inch hole saw. Gets rid of the carbuncles stuck inside.
The 1953-1954 pump pulley is for the narrow fan belt, If wide pulley is installed will fit 1941 and up. Has the aditional by-pas hole but OK to use as it just get covered up if not needed.