FC Air Compressor filter servicing

[iamflagman]

On my 1982 FC35RB one of the things that I am always failing to service is the air filter on the main engine air compressor, mainly because it is out of sight so it is out of my mind. I very seldom have to open up the swing radiator to access the front of the engine and the filter, or to open up the full engine cover that would bring the filter into view to remind me, but I'm constantly checking the oil level and the transmission fluid levels, so I decided to remotely mount the air compressor filter next to the dipsticks.

I used items that I had here in my shop but like I describe in the attached picture, these items can be found at your local parts and hardware stores. Check out the attached picture, or go to the link in my web site, found below.

This is the old style air filter that I had been using;


http://www.pbase.com/image/55075012

This is the NEW AIR COMPRESSOR REMOTE AIR FILTER;


http://www.pbase.com/iamflagman/image/114246964

[warbucks13477]

John with the setup you have I would be very surprised if you are not experiencing slower air pressure buildup as well as increased heat from the compressor because of working harder getting enough air for the size of the compressor. In addition every change in direction of the air flow such as the 90 degree elbow you have also decreases the air flow.

My 1985 PT40 air compressor filter is supplied by the engine air cleaner and is a nice setup so when we change the engine air filter we ar also servicing the compressor air filter. Have you though of ducting the air compressor directly into the front of the air cleaner on your coach with a larger shorter hose? That would give you the same setup that the PT has. Just another idea and something that I believe we will bring up during our rally starting tomorrow. Thanks for the idea something I had not thought about for the FC models. Thanks and if we come up with an adaption of ducting it into the engine air cleaner will take pictures and post them.

[iamflagman]

Originally Posted by warbucks13477

John with the setup you have I would be very surprised if you are not experiencing slower air pressure buildup as well as increased heat from the compressor because of working harder getting enough air for the size of the compressor. In addition every change in direction of the air flow such as the 90 degree elbow you have also decreases the air flow.

All of the fittings, hoses and the filter that I used were larger in diameter than the filter nipple coming out of the compressor, so hopefully that will compensate and be of help in getting enough air into the compressor, but I will make a note of how long it takes to air up in comparison to what it had been doing.

As far as heat build up, the other filter that I had been using was mounted on the compressor air filter nipple that was directly in the airflow of the radiator heat directed at it by the engine fan, but it may be a little higher temperature where I have the filer located now. The filer is in an area where there is still a lot of air flow coming around it from the fan directed airflow under the hollow area beneath the air filter, but I will use my Infrared thermometer to check and see how much difference there is between the two areas the next time I drive it, in a week or so.

My 1985 PT40 air compressor filter is supplied by the engine air cleaner and is a nice setup so when we change the engine air filter we ar also servicing the compressor air filter. Have you though of ducting the air compressor directly into the front of the air cleaner on your coach with a larger shorter hose? That would give you the same setup that the PT has.

In order for the air to be filtered the fitting that would have to be added to the FC's round air cleaner housing on the CAT3208 NA engine that I have, would have to be routed through either the bottom, or the top which I believe both the intake manifold and the doghouse cover would prevent, mounting the nipple to the outside of the round air filter housing would only give fresh unfiltered air and the hose would only be approximately six to eight inches shorter, due to the way it would have to be routed, it currently only has the one oversized elbow and then goes in an almost straight line back to its current location.

Just another idea and something that I believe we will bring up during our rally starting tomorrow. Thanks for the idea something I had not thought about for the FC models. Thanks and if we come up with an adaption of ducting it into the engine air cleaner will take pictures and post them.

Thanks, I appreciate that and if anybody else has any comments or ideas please post them here.

[Randy Dupree]

one thing is for sure,clean air is way better than dirty air.
There is always a trade off when you need to modify something on an FC's engine,due to lack of space!

Tom,the way the compressor filter hose is plumbed on a PT is good,but its pulling against a vacuum or negative pressure area,if it was plumbed into the intake system between the turbo and the head it would be even better,that way the comprssor gets a little "ram" air.
Thats the wy the S60 is done.

On every FC i have ever worked on that compressor filter has been full of dirt or missing all together.so I do think Johns idea is better than that.

[f.wernlein]

Getting ready for our big summer trip I recently checked mine. I had replaced the filter 4 years ago and clean it every other year. This check I decided to replace the filter with new foam.

I use standard air cleaner foam that I buy for my lawn tractor...cut to the size of 2 1/4 long; 1 3/8 high; 1 1/4 wide. Lightly oiled.

My unit has a metal rectangular air box on the left side of the compressor. Two screws hold the small metal lid down. Inside there is a metal air screen, beneath this is the foam filter element.

I have heard/read that some FC's use a paper cartridge type filter...so this specific solution may not fit all years.

[tulipvendor50]

Frank:
Did mine last year, and I have the same as yours, sure needed cleaning.

[iamflagman]

Originally Posted by iamflagman

All of the fittings, hoses and the filter that I used were larger in diameter than the filter nipple coming out of the compressor, so hopefully that will compensate and be of help in getting enough air into the compressor, but I will make a note of how long it takes to air up in comparison to what it had been doing.

I checked to see if the new style relocated filter would affect the Rate of Air Pressure Buildup and found out that at 44 seconds it then meets the 85-100 psi requirement found in the CDL manual quote found in the file below;

Wanderlodge Owners Group > Links, Files, Old Yahoo Forum Database and Downloads > Downloads & Files > Air Bakes System > DAILY TESTING OF YOUR AIR BRAKES SYSTEM.pdf

This is the same as it had done with the old style filter. I haven't driven the 'Bird yet to get it hot enough in the doghouse to see what the temperature differences will be if any.

[iamflagman]

Originally Posted by iamflagman

I checked to see if the new style relocated filter would affect the Rate of Air Pressure Buildup and found out that at 44 seconds it then meets the 85-100 psi requirement found in the CDL manual quote found in the file below;

Wanderlodge Owners Group > Links, Files, Old Yahoo Forum Database and Downloads > Downloads & Files > Air Bakes System > DAILY TESTING OF YOUR AIR BRAKES SYSTEM.pdf



This is the same as it had done with the old style filter. I haven't driven the 'Bird yet to get it hot enough in the doghouse to see what the temperature differences will be if any.

I drove the 'Bird into town today and stopped to check the temperature difference between the old location directly off of the air compressor where it was 185 degrees and the new location behind the air cleaner housing where it was 145 degrees without the fan engaged and 174 at the air compressor and 165 degrees at the new location with the fan engaged. I'm sure that the temperature will change in both locations depending on ambient temperature and engine load.

[howie2017]

Randy, on the series 60 where is the compressor air filter located?

[fxdwg]

The compressor draws from the intake system, so the engine air cleaner is also the compressor air cleaner.