924S Waterpump Bolts Sheared. Resources

8 Waterpump Bolts and 4 studs, length 45mm.
http://www.mcmaster.com/#93275a014/=2qgbbj
50 mm M6 Studs for waterpump

Extractor also necessary if you can't back the sheared studs or bolts out.
These I purchased from Harbor Freight.

Left Hand Twist Drills can also work with drills that can run in reverse to remove bolts.

If your radiator is in place, you will need to use a short drill or angle drill. I found one at Harbor Freight for $30 which was excellent. Link to Drill.

In one case, my extractor itself broke. This required a carbide "burr" (search on Amazon) to be used with the drill to remove the hardened steel insert. The process was time consuming and led to the problem of "enlarged bolt hole"

For bolt holes which are too enlarged, I use Stanley Helicoil, a tap kit to allow stainless inserts to thread into oversized holes. My Helicoil (only 1 needed) was for M8!
Clean and re-clean the gasket surface, and use a new gasket with your new waterpump. My replacement came from URO on Amazon.

Flight School Acronymns

Learning to fly has never been more full of more useless acronyms than today.

Five P's (SRM)
Plan
Plane
Pilot
Passengers (not that this one is second to the last!)
Programming

Three (More) P's (ADM)
https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/media/faa-h-8083-2.pdf

Perceive
Process
Perform

WARMPC? Who comes up with this stuff?
W – Warning Area
A – Alert Area
R – Restricted Area
M – Military Operations Area (MOA)
P – Prohibited Area
C – Controlled Firing Area

N – National Security TFR

ALERTS? [Ok this one is somewhat useful]
A - Airspeed - Maintain best glide speed. 68 Knots in the 172SP
L - Landing site - Locate.
E - Engine. Restart if time permits.
R - Radio - 121.5 Mayday Mayday Mayday Tail Number
T - Transponder - Set to 7700 = emergency
S - Seatbelts - Ensure they are secure

IMSAFE?
I- Illness
M- Medication

S- Stress
A- Alcohol. None within 8 hours of flight. [Airports are conveniently full of bars as are hotels that all Pilots stay...]
F- Fatigue [Crew scheduling makes sure that pilots are fully utilized. This is a controversial one.]
E- Emotional Issues and/or Eating enough!


A TOMATO FLAMES? [VFR Daytime Required Equipment]
Anti Collision Light System (part of preflight check)
 Tachometer
Oil Pressure
Manifold pressure
Airspeed Indicator
Temp Gauge
Oil Temp Gauge
 Fuel Level Indicator
Landing Gear Extend/Retract indicator (if applicable)
Altimeter
Magnetic Compass
ELT
Saftey Belt


NWKRAFT? [14 CFR 91.103]
Notams
Weather
Known ATC Delays (uncommon)
Runway Length
Alternates
Fuel
Takeoff and Landing Distances

Decide Model
Detect
Estimate
Checklist/Choose
i
Do
Evaluate

PAVE Checklist
Pilot
Airplane
Environment
External

924S Cooling System. Testing Why Radiator Fan Doesn't Come On

I lost the water pump at the end of a nice country-drive and had a long 100 mile tow to get home. (about $500!) With the water pump now replaced, I am not seeing the radiator fan come on unless I flip the air conditioning on.

Once the car is powered off, Coolant seems to be leaking from under the engine close to the water pump, but at a slow trickle.  There is no sign of white smoke from the tail pipe or of frothy oil.

Facts:
-> During period that water pump failed, I continued to drive the engine "hot" to get to a safe place. I refilled the coolant once and then stopped a second time. After the tow, I didn't restart the engine until I had replaced the water pump. However, the engine tends to overheat and it seems that the coolant is not circulating. Fan Resistance: Drivers Side: 400 Ohm, Passenger's: 1300 Ohms.

-> When I replaced the Water pump and removed the M6-1.0 studs, most broke in their holes. I therefore replaced the studs with 1/4" 20 tpi stainless bolts. The torque spec used was lower, and the waterpump gasket seal may not have been torqued down sufficiently as a result. That would explain the coolant loss from around the waterpump gasket.

-> Following this Clark's Garage procedure, the fans can power on in both low and high modes.
http://www.clarks-garage.com/shop-manual/cool-01.htm

-> The thermostat was reused and not tested before assembly.

Next Steps:
-> Remove the water pump a second time, test the thermostat and check the gasket for signs of leakage. Use some sealant and correct torque spec for bolts and reinstall.

-> Bleed and Retest the Cooling System