sheared hemi oil pump shaft

526 tfx aluminum hemi. started last nite for the first time and used the accusump to prime 60 psi before the start, fired right up and pegged my oil guage at 100 psi instantly. The needle bounced about 3 times at 100 and then dropped instantly to 0. after a thorough search found the mag drive shaft twisted like a pretzel and sheared off even at pump.
Broken piece fell out of pump no problem, and I opened system 1 pump up and found no problem.
No problem with pump shaft to oil pump clearance, royal purple nitro 50 with outside temp above 90 last nite. I guess I need a 200 psi guage, but what would cause the shaft to twist off instantly? what should oil pressure be at idle? could my bypass be set to high and made way to much pressure?any help appreciated while waiting on new shaft to come in. thanks howard

 

This is what happens when the oil pressure is way, way too high. You end up with a barber pole. Make sure the relief valve isn't stuck in the closed position. Take out the plug and spring and any shims, make sure the valve slides freely in the pump.

 

Tony thanks for the reply. it looks exactly like the barber pole. any idea on a good pressure to set bypass at. should I adjust on a drill first, the check again and fine tune if needed at idle? thanks again.

 

I have seen a TAD team a couple of years ago that kept blowing the hose from the pump to the filter. Happened three times in a row. They checked the relief valve and found it stuck closed. Three starting line oil downs- they weren't real popular for a while. Dave Germain

 

Are you running Titanium Springs? One other thing to check is the Teflon between the Springs, I've seen pieces of the teflon break off, get down in the pan and sucked into the pump, locking up the rotors in the pump and snapping off the shaft.
Also, It's going to be a little tuff with the cam in, but when you drop your mag drive in check and see if the shaft is spining in the bushing freely and also the hex drive end that goes into the pump because the tooling tips that make the mag shaft tend to wear down and the shaft tends to get a little chunkier and doesn't ride in the bushing and pump drive smoothly.

 

My old kb pump did the same think,took it out and spun it with a drill,no problems,spins easy.Put it back on and tested with a drill,tight as heck.Mounting bolts closed up clearance and tightend up pump. I went with a new kb pump and no problems since.
The bolts must of tightened up shaft end clearance,causing it to spin hard.
Also try heating oil to flow easier,hard to spin 50 wt oil cold.............John

 

thanks again guys on the help. I will test the pump on the motor tightened down with a drill to check oil pressure first. I do not want to be the guy oiling the track down as mentioned above. I am curios to see if the bypass is stuck or not. this is a system 1 pump.
I hear the starting pressure is in the 180s to 190s and warm about 130ish. does this sound right? thanks howard

 

That's about what our car does during start, a little less than 130 once warmed up and a little alkyhol mixed in. Like Lorenzo said, check to see if any of the teflon from the valve springs came off and may have lodged into the pump. Also if the block was just machined, it may have had a little piece of slag that might have found it's way into the system.