By Chris Ritter
So here we are, it's March 2015. The garage is getting slightly warmer, pressing work commitments have been satisfied, family flu and sickness has been defeated and some winter woodworking is now complete. There are no more excuses, it's time to get dirty. One small task remains before I can rebuild my engine and that task is overhauling my oil pump. It is a task that I've delayed for nearly two years and it is a task I need to tackle now.
The oil pump in my engine is pretty typical for late 1930's automobiles. A gear on my camshaft drives my distributor and oil pump shaft. The oil pump shaft in turn spins two gears that create the pressure used to deliver oil throughout the engine. In addition to the shaft and gears, my oil pump has a pressure relief mechanism and a floating oil pickup tube.
In many earlier engines the oil pickup tube was fixed in position and often surrounded by screening to keep large debris from entering the oil pump. In 1937, Buick had a nifty floating pickup that stayed floating on the top of the oil reservoir's surface. This floating assembly pulled only the best oil from the top but should any sludge or debris find its way to the surface it was kept out of the pump by a small screen on the assembly. My oil pump assembly was pretty sludgy so I completely disassembled it and soaked everything in a degreasing solution of...well...it's a homemade blend and pretty nasty so I won't give all the details. I will say that it cleaned my pump up quite nicely.
An excerpt from '37 Buick literature showing the floating oil pickup.
A look inside my oil pump after I opened it for the first time. It is pretty sludgy in here!
Degreasing the oil pump float.
After a thorough de-sludging, I inspected the pressure relief mechanism for free travel and then installed a new shaft and gear set. Before I could close the assembly I had to resurface the pump body face with its mating face plate. The faceplate was made of cheap pot metal and had a tendency to warp and become uneven. When this happens the pump leaks and you lose oil pressure. Needless to say, this is very, very bad.
To resurface the plate and assembly I placed a fine grit sheet of sandpaper on top of glass and then worked the pieces in a figure-8 pattern. High spots were quickly discovered using this method but I continued until everything was clean and flat.