Foretravel Owners' Forum

What started out as a simple job of replacing the air filter and the Vacuator (a.k.a. duckbill) valve on our Donaldson ECG Konepac G11-2001 air cleaner ended up becoming "one of those" projects.  The filter had not been replaced recently as near as we could determine. It was not listed as serviced in the records we received when we purchased the coach. You do not want to over service the air filter, but best to have a record/idea of when it was last changed.

The duckbill had visible wear, so that needed to be replaced. We ordered a new filter (P/N P148043) and duckbill (P/N P149099), the parts arrived within a week.  We ordered them from Shop Donaldson Filters for Diesel Trucks, Engines & Tractors (https://www.dieselequipmentinc.com/) ; the items were drop shipped from Donaldson.

New Service Parts

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With the new parts in hand, I removed the filter access cover (held on by three plastic nuts), then slid out the old filter, taking care not to dislodge the dust cake. Knocking dust loose while the filter is still inside the housing just creates a mess you'll have to clean up. You don't want to leave any debris inside the air cleaner housing; if any gets past the filter, it can lead to engine damage (look up "diesel engine dusting" for why this matters).

Once the filter was out, our first problem was obvious: the end of the filter was damaged. That was concerning. Was it installed improperly? Damaged during installation? Perhaps it arrived damaged and someone installed it anyway?

Looking inside the air cleaner I noticed rust/crud build-up towards the back of the housing. I vacuumed all the loose bits out, cleaned with a damp cloth. Then cleaned it with a Scotch-Brite pad, more vacuuming / damp cloth.  While doing the cleaning I could see/feel raised areas about 1/3 to 1/2 of the way back. Looking back at the access cover, it had been pushed down on one side. Light-bulb moment, the air cleaner had met the same immovable object that had caused the Hydraulic Tank problems. (https://www.foreforums.com/index.php?topic=49371)

Next Steps

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Knowing the housing was damaged, it was time to remove it for a better look. It's held in by two mounting bands (Donaldson P/N P004079). Unfortunately, the screws used to loosen the bands were badly bent and wouldn't turn. I considered cutting the bands/screws, but didn't want to risk further damaging the housing. Instead, I unbolted the bands from the chassis. The wrench swing is limited, so doing this it is slow going.

With the filter housing removed, you can see both mounting bands had dug into the canister. The access cover was, IMO, fixable, it just needed to be pressed back out (Note: that cover is not sold as a replacement part). The main body, however, was another story. It was visibly warped, banana shaped with one side nearly 3/4" shorter than the other. I considered ways to repair it, but I couldn't be confident it would make a proper seal. Risking engine dusting isn't worth it.

The G11-2001 (https://shop.donaldson.com/store/en-us/product/G112001/12168) air cleaner is a current Donaldson part and it costs an insane $1,150. We checked numerous salvage yards, but none had any in stock. We bit the bullet and ordered a new one. A week later, still without a shipping notice, I contacted the distributor, who then reached out to Donaldson. Their reply: minimum 12-week lead time. We tried calling many other distributors, hoping one might have it on the shelf, but struck out across the board.

Thumbing through the Donaldson catalog (living large!), I noticed the G11-2501 (https://shop.donaldson.com/store/en-us/product/G112501/12172) had almost identical dimensions to the G11-2001. It also had the same airflow setup. The difference was the 2501 uses a latched service cover and not a bolted one. I contacted the distributor to see if this one was available, and to my surprise it was immediately available and at a bargain price of just $900. A few days later and it was delivered.

New Installation

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I purchased new mounting bands for the install. Note, the bands are fabricated sprung open, you need to hold them closed, with the canister in place, in order to start the clamping bolt. The bands surprisingly "springy", I'm glad I decided NOT to cut the old ones off while under the coach, it would have been an unpleasant surprise, they would have popped open with quite a bit of force.

With the canister held in place and oriented to the inlet/outlet piping, I noticed my next "opportunity". One of the cover latches fell directly in line with the hydraulic tank fitting, leaving no room to release the service cover. The chassis mounts are slots for the mounting bolts, so there is side to side adjustment, but not enough in this case.

There was room available to move the hydraulic tank towards the passenger side, and some quick measurements showed it would be enough. You could use the existing hydraulic tank "Z" brackets (the ones I had bent back into shape) and just drill new mounting holes in the rear wall. Instead I chose to draw up new brackets that had a larger offset and have them fabricated. These gave me plenty of adjustment allowing me shift the tank mounting clamps over as far as possible and still avoid the frame rails.

With new brackets the hydraulic tank was mounted towards the passenger side and the air canister towards the driver side and just like that, the latch now clears! The new canister accepts the same filter as the original. It also accepts ones with the access cover pre-installed on the filter. Basically you have more options when shopping.

The filter minder tap is not located on the lid,  instead its on the rear of the canister. You can reuse the same fitting from the original access lid and just re-route the hose (its the shiny split loom in the picture)

Wow! What a crazy project Steve. When you think you are just replacing an air filter and what should be a thirty minute project turns into weeks and lots of creative problem solving. You are a resourceful man. Makes you wonder what happened that brought destruction to both the canister and the filter housing.

Thank you for sharing the whole project. It helps me to think out of the box thoughts when I face the unexpected.

And why the coach doesn't have the original rear engine door.  It's got a T-handle, not a paddle latch.  I happened to notice coaches older than this had the paddle and went searching for photos.  Near as I can tell, this has a 1996 donor door.

Somebody in the past backed into something.  WildEBeest Rescue has made it right.

Steve, a good time to install a Donaldson particle separator. Air filters last 3x as long and helps with water. Jim.  Donaldson H000886 - SÉPARATEUR VERTICAL, EN LIGNE (https://shop.donaldson.com/store/en-us/product/H000886/12418)   

I replaced the air filter housing in my 1981 Foretravel (which I bought in Wisconsin) because of rust shortly after I bought it. I was able to find a replacement at a salvage yard in Yuma. It's a good thing to look at when purchasing a used coach, particularly if it was exposed to road salt.

Steve im so glad you found this issue and have it resolved. Although you had mentioned that air filters should not be over serviced being in sound condition must be assured before the restriction gauge should be trusted. I was quite surprised at the amount of best described as tire rubber dustI removed after one of our all freeway cross country and return trips. Starting with a new filter I had at least 16 ounces of this stuff in the filter. No restriction indicated. I installed the same precleaner that Jim listed and after the same trip was still as clean as the newly installed filter. Crazy the difference. I now when ever posssible incorporate a Donaldson precleaners. Extended filter life is incredible. I clearly remember looking below the vacuator valve on the precleaner at the pile of dry lake silt piled up below its exit like a pyramid. They also remove water and snow equally effectively. I had installed a Donaldson cyclone filter system on a offroad car with a precleaner. Ive since sold the car about six years ago but the current owner has never changed the filter with hundreds of hours of use. Till clean.  I can't empathize enough to change your vacuator valve every couple of years they get old and stop working as effectively, with the engine running at idle they are in constant motion fluttering open and closed discharging dust. Yes the precleaner has another vacuator valve  that also must be replaced. It's three times bigger. Yes I admit to using my coach on dusty roads with the benefits even being greater for me. The air inlet grate at the top of the coach was sized for a 5.9L or a 8.3L and is not large enough  for the 10.8L IMO for continued freeway use.
Engine inlet grate (https://www.foreforums.com/index.php?topic=42238.0)
Donaldson Precleaner (https://www.foreforums.com/index.php?topic=41252.0)

That Donaldson Precleaner looks like a great item to add thanks for the pointers.  We did add an inlet grate brim/deflector based on
what John Haygarth had done, so that is a good start.

For now I'm going to leave the Precleaner for a future project, the thought of removing that air cleaner again is not sitting well with me LOL,  plus I have to find a place to weld on the extension in a reasonable timeframe, the welders in the area are backlogged this time of year.