Oil pump shim

[Hammerhead]

(05-21-2017 )slowpoke Wrote:  pulled the spring out of dog bone and placed 8 dimes in cup of dog bone inserted spring into dog bone pushed all in.is that okay to do? wasn't easy to force cup in, I didn't buy new o ring though, wonder if i scrapped o ring a bit. i did pull all apart checked all eight dime's there . cant buy new o ring holiday up here in canada till tue. going to put manual gauge on as suggested by jordan486 see what happens. so theres nothing else that can relive pressure ?

Placing the dimes in the dogbone cup is how I do and recommend it. Placing them in the end of the pump has some (small) risk of them not ending up seated properly, unless it's done with the pump fully removed and the bore being vertical as in Rawze's overhaul video series.

An O-ring should be fairly easy to source, Home Depot, Rona, Canadian Tire et al should carry these and they are open this Victoria Day weekend.

I recommend to chamfer the bore opening, as I found mine to be quite sharp, and reinstalling the assembly requires significant effort once shimmed, making centering the end piece with the o-ring less than a simple task. If you decide to chamfer, place a rag or paper towel in the bore BEFORE chamfering to avoid possibly contaminating the pump with metal debris. Of course common sense also says to make sure the oil pan is NOT under the pump while chamfering.

The two possible pressure relief points are;
1)The 150psi relief valve in the oil pump itself. When this relief opens, it dumps the excess pressure directly back into the pan. Unlikely.
2)The oil filter bypass located on the oil cooler directly above the oil filter header. This is the larger of the two Allen head plugs clearly visible. It's purpose is to allow engine lubrication when the oil is too cold to flow through the filter media sufficiently, or if the filter becomes compromised. If you have not updated this relief valve, it is possible that this bypass is allowing some of the oil flow to bypass the filter. Possible.

3)The most likely is that your oil pressure sending unit is getting weak. A manual gauge will verify. If anybody ever asks me about oil pressure, this is the very first thing I tell them to change. It is the most likely component to fail, and even if it hasn't failed, now you have a spare. And every owner/operator should have a spare oil pressure sending unit. Total sensor failure results in engine shut down. Being towed for a $50 sensor that is easily replaced, from my standpoint is unacceptable.