1994 BB AARE engine air filter

[telekellen]

Hi there,
Longtime lurker, first time poster. Purchased a 1994 BB AARE in summer of 2020. Just 'finished' the conversion (are they really ever finished?) and went on our first ski trip over the holidays. Alright, to the point here: Had some power issues - about 200 miles into the trip the throttle was variably responsive and sig. power loss would occur. I'm hoping its the fuel filters (replacing the primary and secondary this week). The primary is black, almost sooty. Fuel was pretty old (~2 years). Because of the weather (snowing and blowing) I had a hard time telling if there was any smoke blowing out of the exhaust during the power loss. It certainly wasn't billowing out...but it could have been puffing a bit of white and I wouldn't have been able to tell. Anyway, I want to replace the air filter as well and can't find much on how this is done. In the photo attached, I assume the filter is the large silvery can. Do I replace the whole can? Is there a replaceable element inside? Any help would be appreciated!

 

[magnakansas]

this is a guess

Yes the air filter is inside the big silver can....

I think the there should be a nut or knob at the bottom of the can.

unscrew the nut/knob and take the end plate off the can.

I think you will find another nut/knob holding the air filter element in place.

unscrew that and the filter will drop out the bottom.

I have never done an air filter on this kind of bus, I have never seen an air filter replacement on this kind of bus.

it is a guess.
william

 

[telekellen]

Thanks magnakansas.

Yeah, there isn't a thumb-knob on the bottom, it doesn't seem like the can is really meant to be cracked open - appears to maybe be glued together? Typically I would just start ripping things apart and figure this out...but with the cold-ass temperatures we have right now I'm less inclined to spend too much time trying to figure this out!

 

[magnakansas]

Telekellen

So try this, look up, or telephone a bluebird dealer, or truck supplies store and find out if an air filter is a big metal can. I have never seen a filter like that but I could also learn something new today.

So, yes it appears that you could have a big metal can for an air filter. Now you get to look for a part number.

William

 

[Iceni John]

If there's no obvious way to replace only the filter element inside the housing, then you probably have a one-piece disposable air filter such as a Racor Eco-BC or Racor EcoLite. Racor makes them in different sizes according to your engine's maximum air intake flow rate, so don't buy anything smaller than what the engine needs. If you have space to fit a larger air filter, it will give less restriction at higher flow rates, and maybe will last longer before your Filter Minder restriction gauge (you do have one?) tells you it's time to replace the filter.

If your bus needs an unusual size or type of air filter, it's worth always keeping one or two spare filters with you on trips, just in case... My Eco-BC is approaching the gauge's red line, so I bought two EcoLites and keep them for the day my gauge goes red. My engine, being an air-hungry two-stroke, needs huge 2000CFM air filters which won't ever be in stock anywhere, so I buy them ahead of time from Harbor Diesel in Long Beach CA.

John

 

[s2mikon]

I had a problem with mine losing power. It ran good about a 100 miles and went lame early up shifts low boost and low pyrometer temp. So I made sure it had full air pressure turned off the engine removed the key and put it in my pocket and had my son press the throttle all the way to the floor. The air servo was not opening the pump to WOT. It also had an air leak hissing noise. Traced it down to the hose where the tee that went to the modulator was. Replaced the hose and was full power again. The air filter is one piece.

 

[telekellen]

Iceni John,
You nailed it. Looks like I've got one of these:
https://ph.parker.com/us/en/disposable-engine-air-filters/71338002

I do have a filter minder, and it's not red-lined, but is close.
Thanks for the help!

 

[telekellen]

s2mikon,
Wow, your observation is nearly identical to mine. Drove about 175 miles just great, then low boost, low power, etc. All of that with no discernable smoke from the exhaust. I will perform a test similar to yours tomorrow! Thanks for the input!

 

[telekellen]

Just to follow up, replaced both the primary and secondary fuel filters and just got back from a ~450 mile trip - and my engine power problem is no longer! Cheap fix!