Johnson Service Bulletin SB-934 - Chrome Plated Water Pumps

January 14, 1963. Johnson Motors explained why chrome plated water pump housing covers may have different surface finishes, and confirmed that both are acceptable.

Johnson Motors Service Bulletin letterhead
January 14, 1963
Bulletin No. SB-934
Accessories
SUBJECT: Chrome plated water pumps.

The chrome pump housing covers illustrated show the two different methods used in finishing the impeller cavity surface. Since chrome builds up to different depths during the plating process, the covers must be ground after plating. To insure the maximum amount of material on the wear points, grinding is stopped before the surface is completely flat, accounting for the difference in surface finish as shown in figure 1. On some covers an additional operation was used resulting in the satin finish shown in figure 2.

Figure 1 shows a chrome plated water pump cover with uneven polished surface; Figure 2 shows a cover with a satin finish
Figure 1Figure 2

The difference in appearance does not indicate a flaw of any kind and pump housing covers with either surface finish are acceptable.

Sincerely,

JOHNSON MOTORS

Robert Compton
Service Department
RC:eb

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