1. Addition of MCRS low pressure fuel pump pressure relief valve for QSK38/50/60
Kelle Ravn
May 20th 2015
(Changed “check valve” in May 18th version to “pressure relief valve” to be more accurate)

2. Description of design change
The fuel drain block has been redesigned, increasing the depth by 55 mm (2.17 in) and shifting the Centinel drain port outward by 10 mm (0.39 in).
A new hose and a ‘T’ fitting will be used to add a pressure relief valve to the low pressure fuel pump, routing overflow to the drain block.
The hose from the low pressure fuel pump to the stage 2 filter head has been redesigned to accommodate the ‘t’ fitting mentioned above.
The elbow on the stage 2 filter head has been replaced to accommodate the ‘T’ fitting mentioned above (QSK38/50 only).
See slides 3-8 for further details
Reason for design change
It has been confirmed that the MCRS low pressure fuel pump and rear bearing could potentially fail as a result of stage 2 fuel filter plugging. To address this, an external 11 bar pressure relief valve will be added to route flow to the drain block.
Potential impact to OEM
The OEM will have to shorten their ‘fuel tank to drain block’ hose by approximately 55 mm (2.17 in) OR accommodate approximately 55 mm (2.17 in) slack in the hose.
The OEM is required to select a flex hose size of at least No. 8, but it is recommended that No. 10 or higher be used to connect the drain block to the fuel tank. This is due to increased restriction caused by the increased return fuel to the drain block.
For OEMs that use off-engine mounted stage 2 fuel filters, the OEM may need to redesign their hose connecting the low pressure fuel pump to the stage 2 filter head.
12/29/2018
Cummins Confidential

3. QSK 38 overview (more details next slide)
Current
Change (to be implemented)
12/29/2018
Cummins Confidential

4. QSK 38 Current Change (to be implemented) 1 1 2 2 3 3 4 4 5 5
Redesigned drain manifold by:
moving the Centinel port outward by 10 mm
adding a new port, which increased the depth by 55 mm
55 mm
110 mm 1 2
New hose 2 3
‘T’ fitting with pressure relief valve 3 4
Redesigned hose to
accommodate ‘T’ fitting 4 5 5
New elbow on
Stage 2 fuel filter head
12/29/2018
Cummins Confidential

5. QSK 50 Current Change (to be implemented) 12/29/2018
Cummins Confidential

6. QSK 50 Current Change (to be implemented) 1 1 2 2 3 3 4 4 5 5
Redesigned drain manifold by:
moving the Centinel port outward by 10 mm
adding a new port, which increased the depth by 55 mm 1
55 mm
110 mm 1 2
New hose 2 3 3
‘T’ fitting with pressure relief valve 4 4
Redesigned hose to
accommodate ‘T’ fitting
New elbow on
Stage 2 fuel filter head 5 5
12/29/2018
Cummins Confidential

7. QSK 60 overview (more details next slide)
Current
Change (to be implemented)
12/29/2018
Cummins Confidential

8. QSK 60 Current Change (to be implemented) 1 1 2 2 3 3 4 4
55 mm
Redesigned drain manifold by:
moving the Centinel port outward by 10 mm
adding a new port, which increased the depth by 55 mm 1
110 mm 1 2 2
New hose 3
‘T’ fitting with pressure relief valve 3 4
Redesigned hose to
accommodate ‘t’ fitting 4
12/29/2018
Cummins Confidential

9. QSK 38 fuel filter options QSK 38 associated dependent options
QSK 38 options affected
QSK 38 fuel filter options
Old option
New option
FF 6125
FF 6235
FF 6126
FF 6236
FF 6135
FF 6239
FF 6140
FF 6237
FF 6141
FF 6238
FF 6169
FF 6240
FF 6182
FF 6241
FF 6192
FF 6242
FF 6193
FF 6243
FF 6224
FF 6244
QSK 38 associated dependent options
Old option
New option
FD 6706
FD 6738
FD 6711
FD 6736
FD 6715
FD 6737
FD 6735
FD 6739
FP 6907
FP 6963
FP 6961
FP 6965
Once the new options are released at P phase, the old options will be restricted in COLS.
12/29/2018
Cummins Confidential

10. QSK 50 fuel filter options QSK 50 associated dependent options
QSK 50 options affected
QSK 50 fuel filter options
Old option
New option
FF 6127
FF 6245
FF 6128
FF 6246
FF 6136
FF 6247
FF 6140
FF 6237
FF 6141
FF 6238
FF 6147
FF 6248
FF 6170
FF 6249
FF 6183
FF 6250
FF 6194
FF 6251
FF 6195
FF 6252
QSK 50 associated dependent options
Old option
New option
FD 6707
FD 6740
FD 6708
FD 6741
FD 6712
FD 6742
FD 6716
FD 6743
FP 6908
FP 6966
FP 6910
FP 6967
Once the new options are released at P phase, the old options will be restricted in COLS.
12/29/2018
Cummins Confidential

11. QSK 60 associated dependent options
QSK 60 options affected
QSK 60 fuel filter options
Old option
New option
FF 6103
FF 66254
FF 6117
FF 66255
FF 6132
FF 66256
FF 6148
FF 66257
FF 6167
FF 66258
FF 6180
FF 66259
QSK 60 associated dependent options
Old option
New option
FD 6709
FD 6744
FD 6710
FD 6745
FD 6714
FD 6746
FP 6909
FP 6969
FP 6911
FP 6970
Once the new options are released at P phase, the old options will be restricted in COLS.
12/29/2018
Cummins Confidential