Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
RV Trip Planning Discussions

Go Back   iRV2 Forums > POWER TRAIN GARAGE FORUMS > Cummins Engines
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
Thread Tools Search this Thread Display Modes
Old 01-24-2023, 03:43 PM   #1
Join Date: Jul 2014
Posts: 85
Fuel Filter replacement on C-Series 6C8.3

The manual says to prefill the new filter (FS1251 filter). It also says to clean the filter gasket surface on the engine. This all makes sense but from reading other posts it seems you better move fast to replace the filter so air doesn't get in the system. How do you clean the gasket surface fast enough that wouldn't let lots of air in? Or is this for a different Cummins engine?

I'd appreciate any advice.


'98 Monaco Dynasty 40' - C-Series: 6 C 8.3 Engine Turbo
- Thanks, Jeff
'98 Monaco Dynasty 40' - C-Series: 6 C 8.3 Engine Turbo - Allison MD3060 - Onan HDKAJ11451DP
411jeff is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free! RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 01-24-2023, 04:01 PM   #2
Senior Member
Warhorse6's Avatar
Join Date: Jul 2020
Posts: 582
Had a similar challenge. My mechanic said to turn the ignition switch on 5 or 6 times without starting. Make sure you leave it on for 4 or 5 seconds each time. This will pump fuel into your filter to eliminate air in your lines. Once you go to start you’ll be good to go. Did exactly what he said and thousands of miles later still no issues. I have a Cummins 450.
2018 Phaeton 44OH
2017 Chevy Traverse Toad
Warhorse6 is offline   Reply With Quote
Old 01-24-2023, 06:45 PM   #3
Senior Member
mackwrench's Avatar
American Coach Owners Club
Join Date: Apr 2016
Location: North Florida
Posts: 2,353
Jeff, I'm guessing since you didn't post how to change filter on a ISC 8.3 yours is a mechanical I can tell you is:

Have your new filter filled with fuel and close by.

If you pour fuel in through the smaller holes, it's filtered.

Once you get the old one off, make sure you replace the o-ring.that maybe on the threads of the filter base. Some have them, some don't.

A quick swipe with a rag on the base will get it clean enough, thread on the new filter and tighten as much as possible by hand.

Most important, where a ragged old t-shirt as the fuel will probably be running down your arm during most of this!

If not, then it'll be pulling some air back though line to tank. So yep, work steady

Your older mechanical engine can be hard to prime, so once you start it, hold the throttle about 1/2 way for several minutes to get any air out.

If it loses prime, remove filter and start over, you may have to looosed a few injector lines to get it stumbling enough to start.
1999 American Eagle
ASE med/heavy certified technician
ASE advanced diesel certified
mackwrench is offline   Reply With Quote
Old 01-25-2023, 02:45 PM   #4
Join Date: Jul 2014
Posts: 85
Yes, it's a manual C Series engine. Thanks for the advice.
- Thanks, Jeff
'98 Monaco Dynasty 40' - C-Series: 6 C 8.3 Engine Turbo - Allison MD3060 - Onan HDKAJ11451DP
411jeff is offline   Reply With Quote

ace, fuel, replace, replacement

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Cummins 6C8.3 engine maintanence manual Ray,IN Cummins Engines 2 10-09-2022 12:06 AM
DP Question, oil & filter change ,fuel filter & air filter chnage schedule ky bob Class A Motorhome Discussions 3 02-01-2020 07:12 PM
6c8.3l high idle Adamsta General Discussion 23 12-16-2017 10:25 PM
Primary Fuel Filter Replace 6C8.3, To bowl or not to bowl??? aRVowl Monaco Owner's Forum 2 05-13-2012 06:22 PM
Engine Fuel filter vs Remote Fuel filter cajunjohn Alpine Coach Owner's Forum 12 12-09-2008 08:26 AM

» Featured Campgrounds

Reviews provided by

All times are GMT -6. The time now is 03:24 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2023, vBulletin Solutions, Inc.