Updated:
05/21/2021

Low Pressure – Fuel Leak From Clamps

Completed
BACKGROUND
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•
•
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Engines reported leaking from low pressure fuel lines in fuel filter assembly.
Leaks reported on L9 engines.
OEMs reporting leaks from hose: Gillig, Spartan Motors, and Tiffin.
Onsite mechanics reported leaks coming from clamp around quick connect fitting.
Sort failure rate table in bottom right corner.

• Current Step 3 actions completed at RMEP include:
• Lineset hold initiated to sort product at RMEP.
• Onsite mechanics requested to tighten clamps using Oetiker tool.
• Inspection hold and screening initiated to test parts prior to assembly.
• Pressurized (90psi) testing for leak detection. ESNF 74783822
• Step 6 actions/investigations:
• Reviewing supplier process controls.
• Evaluating modification of clamp from the supplier assembly.

FAULT CODE/FAIL MODE
• Class 5 Fuel leak reported from low pressure hoses.

ROOT CAUSE
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Class 5 leak detected at the customer locations.
OEM found steady leak coming from the area of the clamps on low pressure hoses.
Intermittent failure across shipped engines.
Part numbers impacted: 5563641, 5563642, and 5563643 supplied by Imperial.
Adding torque to the clamps resolved the leak.

NEXT STEPS
• Step 6 implementation discussions with supplier.
• Review overall design of the hose for opportunities for improvement.

Part No.

Tested

Rejects

Reject
Rate%

5563641

2244

213

9.49

5563642

584

39

6.67

5563643

339

3

0.88

Totals

3167

255

8.05

1

From:
To:
Date:
Attachments:

Monday, June 07, 2021 8:49:08 AM
image003.png

Thank you,
Product Safety Specialist
EBU Product Safety
Cummins Inc.
500 Jackson Street, Mail
Columbus, IN 47201 USA

From:
Sent: Friday, June 04, 2021 3:57 PM
To:
Cc:
Subject: FW: Leaking fuel lines
FYI example of communication between

and CMI on fuel line leaks

Customer Quality Assurance Manager
Cummins Inc.
Rocky Mount Engine Plant
9377 N US Highway 301

From:
Sent: Friday, June 4, 2021 2:10 PM
To:
Subject: FW: Leaking fuel lines
Hi

,

This is one email that I have with Gillig Bus. The QA guy is

.

From:
Sent: Thursday, May 20, 2021 9:03 AM
To:
Subject: RE: Leaking fuel lines
Thanks

,

I will get these into RMEP’s MNC system!
From:
Sent: Thursday, May 20, 2021 9:01 AM
To:
Subject: FW: Leaking fuel lines
Importance: High
FYI, another complaint came through this morning from Gillig.
Found out from
these leaks were on the following ESNs:
74780638
74780686
74781910
74781835
Thanks

for helping with the clean point date, let me know so we can check if current preventative action is robust or not.

Best,
Sr. OEM Customer Quality Engineer
Customer Integration – Bus
Cummins Inc.

From:
Sent: Thursday, May 20, 2021 8:33 AM
To:
Subject: RE: Leaking fuel lines
Importance: High
EXTERNAL SENDER: This email originated outside of Cummins. Do not click links or open attachments unless you verify the sender and know the content is safe.

Good morning

,

We are continuing to see fuel lines leaking at start up, yesterday we had 3 buses in a row that leaked. Currently Cummins rep is doing a fix as fail online but we need to get ahead of this, can you please push to
have all fuel lines either replaced or the crimps checked on all of our Cummins engines in stock before getting installed.
Do you have serial numbers for the clean point of the engines coming out of your plant that have been tested before shipping?
What is the status of your hose suppliers investigation/analysis of the leaking hoses that have been returned?

| Supplier Quality

CONFIDENTIALITY WARNING: This email may contain proprietary or confidential information and is for the sole use of the
intended recipient(s). Any unauthorized use or disclosure of this communication is prohibited. If you believe that you have
received this email in error, please notify the sender immediately and delete it from your system.

From:
Sent: Friday, May 07, 2021 8:19 AM
To:
Subject: RE: Leaking fuel lines
Hello
The returned parts were received at supplier’s end this week. They are going to do testing to calculate exact mass flow leak rate. This testing and analysis will help with identifying the root cause.
The crimping tool is advised as a tightening measure to fix the leak at Gillig, this is a temporary action for now.
I can also comment that while the investigation is ongoing at our supplier, we are working to set up a leak test system at our warehouse as well as supplier’s manufacturing facility.
I am working to get more answers, will continue to keep you updated.
Best,
Sr. OEM Customer Quality Engineer
Customer Integration – Bus
Cummins Inc.

From:
Sent: Thursday, May 6, 2021 12:23 PM
To:
Cc:
Subject: RE: Leaking fuel lines
EXTERNAL SENDER: This email originated outside of Cummins. Do not click links or open attachments unless you verify the sender and know the content is safe.

Good morning

,

Do you have an updates to report on this issue? Talking with
today he commented that the last few leaks he was able to fix using the crimping tool that was provided to him to re-crimp the
hose bands. Does the issue trace back to a crimping problem that the hose supplier was having? Has the root cause been found on their end?
Thank you
| Supplier Quality

CONFIDENTIALITY WARNING: This email may contain proprietary or confidential information and is for the sole use of the
intended recipient(s). Any unauthorized use or disclosure of this communication is prohibited. If you believe that you have
received this email in error, please notify the sender immediately and delete it from your system.

From:
Sent: Friday, April 23, 2021 6:02 AM
To:
Subject: RE: Leaking fuel lines
Good morning

,

At Cummins we use a 7 step product problem solving process to resolve identify, define and resolve issues.
Step 3 is what we consider a temporary fix to an issue until a permanent solution is identified and implemented.
The step 3 in this case is ensuring Gillig does not receive further hoses with a leak defect.
Hope that helps on clarity, let me know if you have any questions.
Thanks,
Sr. OEM Customer Quality Engineer
Customer Integration – Bus
Cummins Inc.

From:
Sent: Friday, April 23, 2021 4:17 AM
To:
Subject: RE: Leaking fuel lines

EXTERNAL SENDER: This email originated outside of Cummins. Do not click links or open attachments unless you verify the sender and know the content is safe.

Good morning
What is “STEP 3”?

CONFIDENTIALITY WARNING: This email may contain proprietary or confidential information and is for the sole use of the
intended recipient(s). Any unauthorized use or disclosure of this communication is prohibited. If you believe that you have
received this email in error, please notify the sender immediately and delete it from your system.

From:
Sent: Thursday, April 22, 2021 3:36 PM
To:
Cc:
Subject: RE: Leaking fuel lines
Hello
We currently have a STEP 3 at the plant leak testing the fuel hoses to the maximum shop air pressure.
There is also a dock closure in place at RMEP for this part to ensure defective ones are screened.
Our Supplier Quality is working with the supplier to get a Step 3 implemented from their end.
Will keep you posted on findings.
Thanks,
Sr. OEM Customer Quality Engineer
Customer Integration – Bus
Cummins Inc.

From:
Sent: Wednesday, April 21, 2021 1:01 PM
To:
Subject: RE: Leaking fuel lines
EXTERNAL SENDER: This email originated outside of Cummins. Do not click links or open attachments unless you verify the sender and know the content is safe.

Good afternoon
Do you have any updates from your supplier on the leaking fuel lines?

CONFIDENTIALITY WARNING: This email may contain proprietary or confidential information and is for the sole use of the
intended recipient(s). Any unauthorized use or disclosure of this communication is prohibited. If you believe that you have
received this email in error, please notify the sender immediately and delete it from your system.

From:
Sent: Friday, April 16, 2021 7:09 AM
To:
Subject: RE: Leaking fuel lines
Hello
about this issue. The hoses that the leak was observed on have been sent back to RMEP for analysis.
I have been in touch with
We are currently in the process of reviewing these for root cause investigation with the supplier.
I will keep you posted as soon as we have our findings and corresponding next steps.
Thanks,
Sr. OEM Customer Quality Engineer
Customer Integration – Bus
Cummins Inc.

From:
Sent: Friday, April 16, 2021 10:01 AM

.

To:
Subject: Leaking fuel lines
EXTERNAL SENDER: This email originated outside of Cummins. Do not click links or open attachments unless you verify the sender and know the content is safe.

Good morning
part of Gillig quality team, I got your contact info from
. We are currently having issues with fuel lines leaking fuel at the clamps,
I am
Have you started a failure analysis or found a root cause of this issue yet? Please let me know what has been found.

CONFIDENTIALITY WARNING: This email may contain proprietary or confidential information and is for the sole use of the
intended recipient(s). Any unauthorized use or disclosure of this communication is prohibited. If you believe that you have
received this email in error, please notify the sender immediately and delete it from your system.

is replacing another 2 hoses today.