C
Hey All
New 800 / 827 build with re-man BRP crank. Leak down test shows bubbles coming out of the mag side stator bolt holes. I loose 1/2 psi in 3 minutes.
On the 01 800 Crank you have a case to crankshaft seal which completely isolates the Isoflex greased PTO bearing from the internal pressures. When pressure testing the PTO side one should not see any air escaping from the external greasing elbow. Agreed?
But, on the MAG side such a seal does not exist. It appears that the inner MAG side bearing has an internal seal, but nothing to isolate internal pressures from the mag side isoflex bearing like the PTO side.
So when pressure testing the crankcase we have nothing specific to seal the outer circumference of the mag side bearings and the crankcase other than bearing fit to crankcase?
One then would have to ask: What keeps the MAG side isoflex grease from slowly washing out or getting contaminated by the internal engine pressures? Does it boil down to the bearing fit to case tolerances? I've read about many instances where case were opened and little to no isoflex remains in the MAG bearings. One has to ask where did the grease go?
Crank Gurus, please comment on this.
Should I expect my leak test to push slight amounts of air around the unsealed side of the MAG bearings and the crankcase and out the upper stator bolt hole?
Yellow Jacket
New 800 / 827 build with re-man BRP crank. Leak down test shows bubbles coming out of the mag side stator bolt holes. I loose 1/2 psi in 3 minutes.
On the 01 800 Crank you have a case to crankshaft seal which completely isolates the Isoflex greased PTO bearing from the internal pressures. When pressure testing the PTO side one should not see any air escaping from the external greasing elbow. Agreed?
But, on the MAG side such a seal does not exist. It appears that the inner MAG side bearing has an internal seal, but nothing to isolate internal pressures from the mag side isoflex bearing like the PTO side.
So when pressure testing the crankcase we have nothing specific to seal the outer circumference of the mag side bearings and the crankcase other than bearing fit to crankcase?
One then would have to ask: What keeps the MAG side isoflex grease from slowly washing out or getting contaminated by the internal engine pressures? Does it boil down to the bearing fit to case tolerances? I've read about many instances where case were opened and little to no isoflex remains in the MAG bearings. One has to ask where did the grease go?
Crank Gurus, please comment on this.
Should I expect my leak test to push slight amounts of air around the unsealed side of the MAG bearings and the crankcase and out the upper stator bolt hole?
Yellow Jacket
