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Topic: Air Bag Replacement 92 U300 (Read 682 times) previous topic - next topic

Air Bag Replacement 92 U300

Hello,

I'm looking for any suggestions on where to get air bags/air springs for a 1992 U300. I just picked it up and I've been digging through the forums looking for information but I just wanted to make sure I have the right part number for the bags.

There is one on the rear that is leaking, you can hear and feel the air coming out of it. They look like they are in rough shape and I was probably going to do all 8 of them just to be safe. It hasn't been driven much in the last few years. Oil filters have 2019 on them for a date for example. But it rode nice and the compressor kept up with the air bag leak without any problem for the 6 hour drive.
1991 U300 Side Aisle 6V92 Silver #3897
2004 U320 40' #6246

Re: Air Bag Replacement 92 U300

Reply #1 –
Check our "media" up on the line starting with "community" and ending with "media."  It has all the part numbers, etc. Conti from Continental Tire usually have the best price. AS9448 is the Conti part #, W01-358=9448 is the Firestone #. Just xref for other brands. This is the correct # for your U300.

I bought stainless nuts and washers as the bags don't come with same.

Most of the leaks face the tire so I carry a tubeless tire repair kit so just hit the bag with a drill bit at the leak and install the plug.

When you change the oil, use a low ash oil. Delo 100 #40 is recommended by Detroit with Shell's Rotella right at the cutoff line. Don't use Delo 400!  Order the oil at a parts store or distributor. Harbor shops always have it in stock. The oil and filter usually cost just over $100. Warm the engine and stab the filter on the bottom with a punch. Drain into a container as you remove the punch. Recommend installing a flush quick drain. Use a vacuum cleaner on the oil fill, remove the drain plug and install the quick drain. You will not lose a drop. Otherwise, it's a big mess. The pan is steel so not much chance of damaging threads and once installed, you never have to worry again about messy oil changes.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Air Bag Replacement 92 U300

Reply #2 –
Good advice from Pierce.

I suggest one small additional step.  Before poking a hole in the oil filter be sure to loosen it just a bit.  Would hate to have someone unable to get the filter off AND have a hole in it.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Air Bag Replacement 92 U300

Reply #3 –
Quote from: wolfe10 –
Good advice from Pierce.

I suggest one small additional step.  Before poking a hole in the oil filter be sure to loosen it just a bit.  Would hate to have someone unable to get the filter off AND have a hole in it.
Yes, our spin-on air dryer was stuck and I had to drill a hole in it, drive a two foot screwdriver sideways through it to loosen it. I had to do this twice as a quarter turn didn't do it. My HD strap wrench broke the strap before that.

If you follow the instructions on the side of the new filter for tightening it, you should not have any problem. But, the last owner may have given it his max effort.  The strap wrenches with the rubber strap don't do the trick as they slip or stretch.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Air Bag Replacement 92 U300

Reply #4 –
I serviced the generator last night, fresh oil and filters. This is the air filter that came out of it. Generator has 6716 hrs and the filters had dates from 2019 on them. Engine is next and coolant for both is on the list.

Air bags should be here friday. Tires are planned for Saturday.

1991 U300 Side Aisle 6V92 Silver #3897
2004 U320 40' #6246

Re: Air Bag Replacement 92 U300

Reply #5 –
While the filter appears dirty, filters become more efficient as they get dirty. Naturally, if they get really dirty, the fuel/air ratio can change becoming richer and decreasing the engine power. In a diesel engine, the EGTs can rise as the restriction increases over the manufacturer's recommendation. That's why checking the restriction gauge is important. Both our main diesel and generator have the gauges. It's also important to know the restriction limit for each engine manufacturer. It's been posed several times here.

So, changing your filters early may not be doing your engine or pocketbook a favor. I'm not a filter expert but Donaldson is so read their information on filter efficiency here: Servicing Your Air Filter – to Change or Not to Change? │Donaldson Engine &...

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Air Bag Replacement 92 U300

Reply #6 –


I don't think my generator has a restriction indicator on the air filter. I've found the engine one, but I can't find one on the generator.
1991 U300 Side Aisle 6V92 Silver #3897
2004 U320 40' #6246

Re: Air Bag Replacement 92 U300

Reply #7 –
I just went out and took a foto of ours. If you don't have one, they are cheap and easy to install.

The big diesel air filters/cleaners may partially collapse if they get very damp as in the U300/U280 where the air intake is right behind the rear tires on all but the last year. When we purchased ours, the dirt was about an inch thick on the element and driving in the rain on the way home from NC, partially crushed it. Wish I had a photo of how dirty it was. Coach was a lot faster with the new one.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Air Bag Replacement 92 U300

Reply #8 –
Yup, relying ONLY on the air filter minder for when to change the filter can get you in real $$$$$ trouble.

Yes, a high restriction reading is ONE of the reasons to change the filter.

But, as Pierce pointed out in the post immediately above, if the filter element is compromised (water, broken pleat, incorrect filter element, etc) the air filter minder reading will never go high, as the air (and dirt) go through the hole, not filter media.

A very good idea (i.e. filter cheap, engine expensive) to change the air filter every 3 years or so and make absolutely sure that the new filter has wire mesh support on the suction side of the filter.  And, the suction side can be on the inside OR outside of the filter depending on whether air comes in the outside and goes to the turbo from the inside OR outside air comes in the center and goes to the turbo from the outside.  Either works just fine, but you have to verify that the filter element is supported properly.

Yes, some filters have the wire mesh on the inside and outside so they can be used in both filter flow configurations.

AND, YES, WE ARE STRAYING FAR AFIELD FROM THE ORIGINAL TOPIC= AIR BAG REPLACEMENT.

PERHAPS WE SHOULD GET BACK TO THAT AND IF MORE AIR FILTER DISCUSSIONS OR BASIC "CARE AND FEEDING OF THE 1992 U300" ARE OF INTEREST (AS THEY SHOULD BE), PERHAPS START A NEW TOPIC. THAT WAY, OTHERS IN THE FUTURE WILL BE ABLE TO USE THE SEARCH ENGINE MORE EFFECTIVELY.

THANKS.
BRETT/MODERATOR

Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Air Bag Replacement 92 U300

Reply #9 –


I got one side, front and rear done, Waiting for the other side to be in the shade. Pulling the fender off was pretty easy.

Big Rig Components is where I ordered the bags from. They look good so far.
1991 U300 Side Aisle 6V92 Silver #3897
2004 U320 40' #6246

Re: Air Bag Replacement 92 U300

Reply #10 –


Old air bags that I removed. Left pair are the fronts, right pair are the rears. The rears really take a beating back there. The fronts didn't need to be changed yet, but it's one less thing I need to worry about for a while now. The rears were leaking, I could hear and feel the air coming out of them. Not fast enough that the engine compressor couldn't keep up, but it's not like the leak was going to get slower. If anyone is wondering how much abuse these bags can take, these were still functioning on the coach and handled a 6 hour drive home without issue.
1991 U300 Side Aisle 6V92 Silver #3897
2004 U320 40' #6246