1. DQ03DR090 High Pressure Coolant Pump Failure
VQ Crankshaft Machining

2. Concerns 6 failures/yr = $47,484.00 in pump replacement costs
72 hours production loss / 216 man hours of maintenance labor during the last year Sumitomo was used.
12 month average rate of failure was 1 pump every 2 months.
Excessive motor / pump noise.

3. Cause & Effect Diagram:
Man
Material
Coolant Type
Filter Changes
Coolant Temperature
Pump
Failure
Tight Tolerance Pump
Inadequate Filtration
FTL Type Operation
Filter Replacement Frequency
Machine
Method

4. Why #1 Why did we have pump failures?
The coolant system was filtered to 25 microns and used a non-repairable Sumitomo Gear Pump.
Due to the tight tolerance of the gear pump Sumitomo suggested 10 micron filtration to guarantee long-term reliability.

5. Why #2? Why didn’t we replace the 25 micron filters with 10 micron filters?
The flow rate needed for the high pressure system was too large to use 10 micron filters without excessive size and cost increase.
Therefore the only improvement alternative was to replace the pump.

6. Toyota currently uses Knoll pumps with zero failures in 5+ years.
Improvement # 1
Replace the Sumitomo gear pump with a Knoll screw pump.
Improved reliability
Toyota currently uses Knoll pumps with zero failures in 5+ years.

7. Improvement # 2
Replace the loud pump motor with a quiet, efficient motor.
Motor horsepower reduced from 50hp to 40hp.
Noise reduced by 10+ decibels.
Need for a sound reduction shroud eliminated, reducing the amount of time to access the motor.
Original
New Style

8. Pump Comparison
Knoll is capable of handling contamination up to 50 microns. No filter upgrades needed.
Knoll cost $6,924.00
Knoll is easily repairable.
Knoll lead time is 48 hours.
Sumitomo requires 10 micron filtration. Filter upgrade required.
Sumitomo cost $7,914.0
Sumitomo is non-repairable
Sumitomo lead time is 60 days

9. Complete drop in Assembly
Knoll designed and manufactured a complete drop in assembly for safe/easy installation.
The cost was $10,700 each for a total initial investment of $21,400.
At a failure rate of 6 pumps/year the Return On Investment was 2.7 months.

10. Additional benefits of this activity
$26,084 replacement savings the first year.
$47,484 each of the following years.
5 year projection
Replacement cost savings
$216,020
Labor cost savings
$50,350

11. Horizontal Deployment via GMR.
Knowledge Sharing
Facts and knowledge of this improvement will be shared with other Nissan Machining Facilities through
Horizontal Deployment via GMR.

12. Questions / Comments