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Onan Diesel Generator Repair -- Houston Area

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The small coolant leak I had from my Onan 7500 watt Quiet Diesel generator has grown worse meaning time for repair.   The generator is not on a slide out tray thus it needs to be dropped out of the frame an onto the ground to remove the cover and access the engine.   For the moment I have an appointment for next Thursday, 8/9/18, at Cummins Coach Care (Cummins Service Center) on I-610 on the northeast side of Houston.     In addition to finding and repairing the coolant leak, what other "routine maintenance" should be performed while the generator "is on the ground"?   I'm thinking replace any belts, replace coolant hoses, thermostat (presume it has one?), etc.   Should the glow plug be replaced?  The generator is a 2007 model and next week will be the first time the engine has ever been exposed.

Any routine maintenance items for the generator itself?  Replace brushes perhaps?   The generator has 600 hours of use.

Also, for folks from the Houston area, does the Cummins Service Center provide good service?   Because the generator has to be dropped to the ground to access the engine, the other RV repair businesses I've called are very reluctant to do the work.

Thanks for your thoughts / guidance!

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Mike they took my 10KW out and replaced the brushes in 2015.  Have nothing but praise for their ability!  Don't forget to join Cummings Club, when you get there...10% off ! :wub: 

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Mike, There is a standard parts replacement when doing the repair on the 7.5 / 8 KW units at the 1000 hr. mark.

Replace the air filter, fuel filter, fuel pump, the water pump drive belt,(Water pump?) check the glow plugs(They often just replace them because of the labor involved in dropping them) check injectors and check the system control board. The oil filter and oil is replaced. The unit should be then tested before being reinstalled !!!

So ask questions - as a general practice take a picture of the connection in the 4 in. square "J" box where the generator output interfaces with the Coach wiring going to the ATS.  There are a number of items that need to be removed to allow the unit to clear the opening. Go over the process with the shop shop job writer.

In your case add coolant and radiator. What coolant do you run in the coach engine? will it work for the generator. Same coolants means one less item to carry. 

Rich.

Cumming Onan Texas.

39. Cummins Rocky Mountain 14333 Gateway West El Paso, TX 79928 Toll free: 800-800-4240

40. Cummins Southern Plains 7045 N. Loop East Houston, TX 77028 Toll free: 800-474-7421

Oklahoma

34. Cummins Southern Plains 16525 E. Skelly Dr. Tulsa, OK 74116 Toll Free: 800-722-2743

 

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Several years ago I had to get towed to Cummins Houston. It would have taken six weeks for Winnebago to start a manufacture of the engine wiring harness - don't keep them in stock and they re-manufacture them on the go. Houston Cummins was able to repair the harness and I was on the road in about 4 days.

Great service.

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Replace the coolant temp sensor, it's a bear to access on a slide-out genset. Sometimes it has been there so long it's corroded into the metal housing, which breaks  when a rough hand is on the wrench.

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An update for the forum.   I ended up taking my motorhome to Cummins Coach Care in Houston and I'm glad I did !!   They don't have the 3-4 week back log of work that RV Masters, Camping World and other repair shops in the Houston area have.   Justin McDonald (Shop Supervisor) has been fantastic to work with.   The coolant leak was due to a crack on the bottom the coolant reservoir due to the plastic being eleven years old and brittle.   The generator had to be dropped out of the frame to do the work (motorhome placed on hydraulic lift, hydraulic work table placed under the generator to remove it, etc.).

While "on the ground", I had most of the "1,000 hours Service" work performed in addition to replacing the coolant tank:

  • All hoses replaced (including new clamps, gaskets, etc.)
  • Belt replaced
  • Thermostat and temperature sending unit replaced

Justin said my generator with 600 hours of use is in "great shape" and advised that "valve lash adjustments" in the generator's engine and replacing brushes in the generator would be money wasted so that work was not done.

While waiting for the new coolant tank to arrive, I also had Cummins Coach Care perform the annual "main engine" and chassis service.  The cost to replace engine oil and oil filter, replace the in-line fuel filter and fuel filter/water separator, lube the chassis, inspect and top off other fluids, check tire pressure, etc. is price competitive with the Houston area Mobile RV Lube business I've used before.  Again, Justin was open and honest when he advised that the engine air filter did not need to be replaced.  I also had the charge air cooler inspected and it was found to be in good shape with no cleaning needed.

I also asked for the air system drier/filter cartridge to be inspected since it was over two years old.  Justin's advice was to replace the cartridge given all of my motorhome use has been in the humid Gulf Coast area.  

I will retrieve my motorhome from Cummins Coach Care this coming Wednesday (8/30/18) after a ten day stay which is quite short compared to 3-4 weeks at other shops.   I don't yet know what the final cost is for all of the work as Cummins Coach Care has not finalized if my XtraRide extended service plan will pay for the generator coolant reservoir replacement.   If XtraRide pays nothing, my total bill will be ~$2,500 = $1,800 labor + $500 parts/oil/filters/air dryer cartridge/etc. + $200 taxes.   Cummins Coach Care uses Valvoline Premium Blue 15W-40 oil which per the Valvoline website is "endorsed" by Cummins.   I've never used Valvoline brand engine oil but with the Cummins endorsement I presume it has to be "OK".

I also learned that Cummins Coach Care has capability to perform chassis, coach and generator maintenance for motorhomes.  Their capabilities are not limited to just Cummins engines and Onan generators maintenance.   Based on this very positive experience, they have moved ahead of RV Masters in the Houston area as my first stop for shop maintenance work. 

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As expected, and thanks for the update.
Another fine place is Houston Freightliner just down the road from Cummins but reservations would be necessary with their backlog. I believe they are now an Oasis Shop.

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