Monday, October 26, 2015

Start the Engine and Look for Leaks

Final test:

With all the parts back in their respective locations, all fluids filled and a temporary wooden plug shoved into the oil fill hole, I was ready to start the engine and see what I screwed up. I was seriously expecting some obnoxious clanking sound indicating some bit or another was left lying about inside the case. I was wrong. The engine started normally, sounded as it always had and best of all the oil pressure was back! I was now getting about 70 psi at half to three-quarters throttle and about 45 at idle. Problem solved. I only wish I knew what I did.

All done. Looks no different.
Okay, I think I really do know and it is rather embarrassing to admit that I probably did not need to replace the oil pump or any of the rubber or gaskets inside the case. When I had the case off I pulled a couple of bolts off because it was not obvious what they did or what lay behind them. One of the bolts looked suspiciously like the bolts that sealed the two pressure release valves on the oil filter assembly. These pressure relief valves are very simple -- just a spring with a ball bearing in a channel. The spring holds the ball against a seal and when the pressure is too high the spring compresses, the ball moves and the oil pressure is released back into the crankcase. Looking at the exploded parts diagram it appeared that this was another of those relief valves but did not have the spring or ball inside. This valve was not mentioned in the service manual so I only knew of it from the parts diagram. I wasn't sure if this was one of the modifications to the engine that Universal had made or whether the spring and ball should really be there and just were missing. I ordered the parts anyway and this, their absence, was, I suspect, the reason for the low oil pressure. Of course, that means that I had been running the engine for four years with low oil pressure. I have no idea why those bits were missing. Sigh. So now I have a new oil pump, new rubber and gaskets inside the timing case and oil pressure. Hopefully I will not have to repeat this for another decade or two.

1 comment:

Neil Lambert said...

I have some questions for you about removing the timing cover.