What Actually Happens When Cormier After The First Death Comes Up in My Shop
I run a small restoration crew and we deal with a lot of old machinery that has been sitting for years. About eighteen months ago, a client brought in a 1978 Press-Gast turbine that had been water-damaged in a flood. The maintenance log showed the last running date was 2009. When we tore into it, we found something that took me a while to figure out because the literature on it is sparse. The term Cormier After The First Death comes from a specific failure mode in older heavy-duty compression systems. It's not a widely discussed problem outside of certain industrial circles. Here is what happens, how I deal with it, and where people commonly go wrong.
Cormier After The First Death Explained
The core issue has to do with what happens inside a multi-stage compressor after the first major bearing failure. Most mechanics stop there, assume it is a single bearing job, and rebuild around what they see. That is where the real damage hides. When that first bearing goes, the rotor shifts microscopically. I am talking about movements measured in ten-thousandths of an inch, but over a cycle count of tens of thousands, those small shifts accumulate in ways that warp the housing bore alignment. The secondary and tertiary stages then see misalignment that was never in the original spec sheet. I learned this the hard way on a Deutz air compressor in my own garage shop. I replaced the primary bearing, reassembled it, fired it up, and it ran fine for exactly forty-three minutes before the whole thing seized again. Same symptoms. I tore it back down, looked at the second-stage thrust plates, and they were scored in a pattern that made no sense unless the shaft had been walking across the faceplate the entire time. The housing bore on that second stage was already oval from the initial misalignment. That is the After the First Death part. The first bearing failure sets off a chain reaction that damages things the next mechanic never thinks to check.
The Actual Inspection Process
When you suspect this has happened, do not start tearing out bearings blindly. The first thing you need to do is measure the housing bores with a celestial bore gauge, not a micrometer alone. You need to check for out-of-round and taper. I use a torque-angle method when reassembling anyway, so I already have access to the data I need. Here is the sequence I follow. I remove the casing covers and visually inspect all three stages of the bearing seats. Look for scoring patterns that run diagonal across the bearing face, not radial. Diagonal scoring is the tell. Then I take bore measurements at four points around each stage — top, bottom, left, right — and record them. If the difference between any two points exceeds .002 inches, you are dealing with a warped bore, not a bad bearing. From there, I check the rotor runout on a set of V-blocks with a dial indicator. The reading should not exceed .0015 inches total indicated runout. Anything higher means the shaft itself has taken a bend or the journals are worn beyond serviceable limits. This is where most people miss it. They assume the shaft is fine because it spins. A bent shaft will spin just fine until it starts pulling the bearings in at an angle, and then everything fails faster than it would have from the original bearing issue alone.
Rebuild Approach That Actually Works
If your bore measurements show distortion, replacing bearings alone will not solve anything. You need to address the housing. There are two routes here. The first is bore reaming to bring the housing back to a true round, then installing oversized bearings to match. The second is swapping the housing entirely if you can find a used one in decent shape. I prefer reaming when the housing material allows it. Most of these older compressors use cast iron housings that can handle a light ream. You want to leave at least .125 inches of wall thickness after the ream, or the housing will crack under thermal cycling. I have seen people ream too aggressively and then wonder why the housing split three weeks later under load. Once the bores are true, install new bearings with the correct preload. Do not skip the preload check. These compressors run at high RPM and the bearing preload affects the internal clearance, which affects the compression ratio. If the preload is wrong, you get overheating and premature failure again. I set preload to the manufacturer spec and then verify by checking the turning torque on the shaft with a spring scale. It should turn smoothly with minimal resistance. If it binds, the preload is too tight. If it spins free with zero resistance, you are running loose and will eat bearings in a few hours.
A Specific Edge Case That Saved Me a Job
Last spring I pulled a Compair screw compressor off a job site in Louisiana. Client said it was doing the same thing — ran for an hour or so, then seized. Standard procedure, right? Replace the bearings and be done with it. But I remembered the pattern from the Press-Gast turbine and did the full bore inspection first. The first-stage bore was within spec. The second-stage bore was .004 out of round. The third-stage bore was untouched. So the damage had not propagated as far as I expected, which meant I could do a cheaper fix. I reamed just the second stage and installed oversized bearings. I also swapped the second-stage seals because they were swollen from moisture exposure during the flood that took the compressor down in the first place. That moisture point is worth mentioning separately. Water intrusion and bearing failure interact in ways that are not obvious. The water gets in through the seals, sits in the bearing cavity, and the steel bearings corrode on the inside race. That corrosion is what causes the initial failure. Then the misalignment does the rest. If you replace the bearings without addressing the seal condition and any remaining moisture in the housing, you are just setting up the next failure. I dried out the housing with compressed air and a heat lamp, installed new seals, reassembled with proper torque sequence, and ran the unit. It has been running for six months now without issue. The client was skeptical at first because the quote was lower than the other shops gave him, but the lower quote was accurate to the actual problem, not an upsell.
What This Approach Does Not Fix
I need to be straight about the limits here. Cormier After the First Death does not apply to every compressor failure. If the original bearing failed because of lubrication starvation, contamination from dirty air, or a manufacturing defect in the bearing itself, and the housing bores are still true, then this is just a standard bearing replacement. Don't start reaming bores that don't need it. That will only create a new problem. Similarly, if the rotor is severely damaged — scoring on the journal surfaces deep enough to feel with a fingernail — then reaming the housing is not going to help. The rotor needs to be replaced or sent out for professional machining. I have seen people try to run with a scored rotor and wonder why the new bearings failed in two weeks. The rotor surface condition matters just as much as the housing alignment. Also worth noting: this issue is most common on compressors older than twenty-five years where the original manufacturer documentation is hard to find. Newer units tend to have better tolerances and more robust sealing that prevents the kind of misalignment progression I described. If you are working on a newer machine and seeing similar symptoms, the root cause is probably something else entirely, like a failed coupling or a misaligned motor mount.
Where to Get the Right Parts and References
There is no single manual that covers this failure mode comprehensively. The best references I have found are scattered across old Service Bulletins from Deutz, Press-Gast, and Compair. Some of these are available through the original manufacturers' websites if you have a account number. Others you find in used form on auction sites or in technical libraries. The Press-Gast service bulletin PB-78-03 is the one that first described the post-first-bearing-failure alignment issue. It is not easy to find but it exists. For parts, I order from specialized industrial bearing suppliers rather than general auto parts stores. The tolerances matter here. A $40 bearing from a big-box store will not hold the same spec as a $120 SKF or Timken unit designed for compressor service. The difference shows up in how long the repair lasts. I would rather spend more upfront than tear the whole thing apart again in four months. If you have the model number and serial number of your unit, the most reliable path is to contact the original manufacturer's support line directly. Some of them still honor warranty on replacements for legacy equipment. It never hurts to ask.
