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Compression Fittings
I have been using brass compression fittings when I replace the push-in air fittings or other modifications. This has included using a 1/4″ brass sleeve and brass insert.
When I replace my exterior refrigerator water filter annually, it attaches with brass compression fittings; however, I use a plastic 1/4″ sleeve.
However, I’ve read some articles that state when using brass compression fittings on a plastic airline vs. a copper pipe fitting, you should use a plastic sleeve and use a brass sleeve only with copper pipe.
What do others use?
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12 Replies
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I have never seen or used a plastic sleeved fitting except when the entire fitting was plastic and it was part of a water system, and not pneumatic.
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I’ve been told that, too, and used both with brass fittings and plastic pipe. I’ve had one failure of the plastic ferrule.. I only use brass ferrules and sleeves now.
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If you have compression fittings they are likely not in need of replacement. But push in fittings are a whole different animal and since they don’t age well they should be replaced.
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I hope you read or have read the multiple threads about the discrepencies on the air bag numbers from Prevost. My bus has always struggled to get to ride height in the front. I am in the process of putting the taller Mae West style on there. Just waiting for the reducing bushings for the larger air tap.
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Jeff, we put the “Mae West” bags on the front in an effort to gain a couple more inches. To do so you’ll likely need to drill a larger hole in the top mount to accept the larger diameter air inlet. Also you’ll need a larger (and thinner) lock nut.
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Thanks John, I already have the holes drill out to 1 5/16″ and the new lock nuts fabricated. I remember reading something about those facts before but i could not find the post. Did the change raise you up any? Thanks
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I believe the air bag heights are not why the front won’t rise. The Mae Wests have a larger diameter, which means more square inches of lifting area.
At the time early 90’s buses were being built Marathon and Country Coach were both building coaches that exceeded the Prevost front axle weight rating. To make matters worse, some owners were adding weight to the front axle by adding a lot of heavy personal items in the bays towards the front, or replacing lighter weight carpeting with granite tile.
To get the front to rise owners learned to lift the tag axle. The situation was so bad Prevost had a design change to use the Mae West bags, but also to add a second set of shocks to the front axle for a total of four.
The first step to determining what is required is to get axle weights. If the front axle is within the limits the fix might be as simple as getting the correct air bag, something that does not require any modification. That is very important because some larger air bags have the potential to rub and making the change is only going to create the potential to have air bags with holes worn in them.
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My log books went with both my XL coaches so I am going by memory and hoping if my memory is wrong, someone will post the correct information.
Prevost had at one time a lot of air bag part numbers because they had different ones used on seated coaches, kneeling coaches, 40 foot conversions, 45 foot conversions, entertainer coaches, etc. So they determined they could reduce the number of different air bags and came up with two common part numbers. One was 630059, and another was 630060. The two numbers somehow through an error got transposed and the 630060 air bag was called for as a front axle air bag.
If my memory is correct that was not the right air bag and that one would not lift the front beyond the normal ride height. The 630059 was the correct air bag for the front axle and if that air bag was used the coach would easily come to ride height and above if required for leveling.
Do not order air bags based on my numbers above unless you verify they are accurate. My memory isn’t that good and I have no log books to refer to for the correct numbers.
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Below are the correct #s for our bus, even thou Prevost tried to sell us the wrong front bags. I knew better thanks to folks on this forum.
Air Bags
Steer x 2 – Prevost# 630259, GY# 1R11-244(MaeWest)
Drive x 4 – Prevost# 630104, GY# 1R11-088(DoubleFlare)
Tag x 2 – Prevost# 630259, GY# 1R11-244(MaeWest)
Jeff and Lindsay
91 Marathon XL -
Jon is correct. We installed the #630059 bags and they did raise the front slightly, but not a great deal likely due to the eight (8) house batteries directly over the axle. I don’t remember the bag specs but at the time we looked very closely at the widths and have made sure there is no rubbing.
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1R11-244 is what i am installing on the front. I will do the tag next. Thank you Don for all of your research and documentation on this issue. I recognize you as one of the best purveyors of the hands on procedures parts numbers here. Some of these types of issues become old news pretty quickly and are sometimes hard to find in the archives. Thanks to Jon for revisiting this and other matters as often as needed to keep everyone informed.
I have some questions i would like to ask. I know this issue is off topic from the original posters question so i will start a new thread.
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Thanks Don. I had a zero where there should have been a 2 in the air bag part number.
630259 is the correct front axle air bag number for XL coaches. And if you have them and the coach will not rise as it should it is almost a given your converter built a coach with a heavy front axle and with personal belongings added to the problem the air bags may just not be capable of performing like they should.
Going to larger diameter air bags is more than likely going to cause the air bag to rub at some point in the front axle travel or the steering wheel travel or both.
Reduce the weight.
Jeff and Lindsay
91 Marathon XL
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