Generator oil fill tube leaks

Dyno Bill · 04-17-2010, 10:44 PM

Upon filling my Onan HDKBA 5.5 after changing the oil, most of the oil began running out the bottom cover. After doing some searching I found that there have been problems with a rubber joint that goes between the filler tube and the engine. So far I haven't found any help with the fix other than take it to a shop.

Has anyone else had this problem? How did you fix it, can a repair be made without pulling the generator from the coach?

**RV Wizard** · 04-18-2010, 02:53 AM

The repair is a pain even with the generator out. To do it while in the coach would depend on how much room you have. Is the genset in warranty? That would be good.

Dyno Bill · 04-18-2010, 08:29 AM

No, it's not under warranty. Would a regular RV repair shop be capable of fixing this?

**RV Wizard** · 04-19-2010, 03:07 AM

If the shop has a Onan generator technician; it will be no problem. Otherwise a technician that has not done this before, will be learning on your dollar, if the job is not flat rated. There are many variables as to how long it will take to remove it from the coach. Once out the job should only take an hour by a knowledgeable technician.

Dyno Bill · 04-19-2010, 02:16 PM

I've got the generator out of the coach, I can see the filler tube bolt at the engine case, is there a write up procedure to get to it or should I take it to a service center?

Thanks, Bill

Dyno Bill · 04-19-2010, 07:29 PM

Nevermind, we got it apart, only had to pull the air box

jamorton · 06-18-2010, 12:14 PM

I have diagnosed the problem with my HDKBA generator. The rubber oil-fill tube is torn where it enters the metallic fitting bolted to the crankcase. Mine was torn about 90% of the way around. Thus, whenever I put oil in nearly all of the oil spilled out into the bottom pan of the generator and eventually onto the floor.

In order to get to this area of the generator to replace the hose ( about $80 for the part btw ) I removed the (from the front) right side cover, front cover and air-box. My generator is bolted to the frame of my coach - not on sliders. It is a pain to remove these covers, an air-powered ratchet wrench is a real blessing here. Nearly all of the bolts are identical and have a 10mm head. The air-box is held in with 3 nuts threaded onto threaded studs which come up out of the bottom plate of the engine. If you look on the bottom plate along the rear edge of where the airbox sits, you will see a round bump - that is the stud base - that is the clue to locate the other (i think 2) studs and be able to remove the nuts. I also removed the plastic air-filter holder and there is a hose clamp bolted onto the airbox next to the upper air-filter box mounting bolt - those hoses prevent the airbox from being removed till you take that clamp off (again 10mm).

Removing the front cover required me to disconnect the generator outputs from the terminal block where the coach wiring attaches ( easier to leave the coach conduit and wiring in place on the cover) as well as disconnecting the power wires from the two circuit breakers. The hobbs meter has 2 connections, on mine, the rearmost (closest to the generator engine) had heat shrink on it. The start / stop switch is connectorized - just disconnect the connector from the back of the switch.
The radiator overfill bottle will have to be jimmied out of the front cover notch, and the radiator fill slid out of the cover plate. (what a HORRIBLE design!!!) This thing is like a Chinese puzzle!

Note -- disconnect battery power and AC power from your rig before working on this stuff. Wear seatbelts. Use hearing protection. Give your spouse hearing protection so they won't hear you cuss. Caveat Emptor, I am not a mechanic, but I saw one in a movie once.

Jim

I am picking up my oil tube in an hour or so, I will post more next week on the adventures of replacing it.