Air Leak

[AJ]

On a MC8, I hear hissing sound, air leak, from right side tag axil behind the tire.
The air bag shows no crack or weather sign, the tire is in good shape. Where would it be leaking from? Is there a way to service it with out removing the tire/wheel? 

AJ

[larryh]

Block it up firmly chock wheels buy some kids bubble blowing stuff get under there and use brush and coat all fittings bags etc you will find it.

BE SAFE Remember Body comes down on suspension as we get older we get thicker  and a bus coming down toward you will get your attention FAST BLOCK IT UP

LarryH

[Busted Knuckle]

On a MC8, I hear hissing sound, air leak, from right side tag axil behind the tire.
The air bag shows no crack or weather sign, the tire is in good shape. Where would it be leaking from? Is there a way to service it with out removing the tire/wheel? 

AJ

Well ya sprinkle the magic dust around the bus and ya say 3 times loud and fast "Bus wizard, oh great bus wizard please fix my bus, oh great bus wizard! bus wizard, oh great bus wizard please fix my bus, oh great bus wizard! Bus wizard, oh great bus wizard please fix my bus, oh great bus wizard!" And wallah! Nothing will happen!
OK AJ on a serious note, there are literally a hunderd possibilities where it could be coming from! Air beams, air lines, air line fittings, air bags, air bag mounts, relay valves, regulators, brake chambers, and on and on and on! OK first thing to do is to get it blocked up, or up on ramps, or whatever ya gotta do to were it's raised up enough to get under it. Or take the wheel off, or both! Then once you can get too and see things better, get some kind of soap water solution (I personally like the bubble stuff that they sell for kids to blow bubbles with and put it in a spray bottle it really bubbles up when it finds a leak) and with shop air hooked to it or air built up. Start spraying everything that has an airline or more hooked to it and watch for bubbles ! Some are easy to find and some are not! FWIW  BK  

[jjrbus]

Gee BK, what kind of advice are you giving? A spray bottle? Get a squirt gun and have some real fun

[JackConrad]

I had to replace a tag axle air bag on our MC-8 a couple years ago. The metal plate that is the top of the air bag (and bolted to the air bag mounting plate on the bus frame) had several pinholes rusted through it. Only way I finally found the exact cause was after I removed the bag. I did get bubbles from between the bus frame mounting plate and the top plate of the air bag. Jack
PS: this was all much easier with tag tire removed.

[Ncbob]

AJ, one of the best investments I ever made was an Ultrasonic leak detector from the E-place.  Now, it wasn't necessarily for Freon, but it will detect an air leak as soft as you could blow.  It has a headset and a 9V powered wand with a volume control..  The neat thing about it is that you can tape it to a stick and sit back safe and not have to get under the bus while searching.  It's led me to a few I wouldn't have otherwise found with soapy water.

Mine was made by OTC Tools and is a big hit at rallies too.

NCbob

[Tony LEE]

Also, there are a lot of potential leaks in the engine area including valves mounted on the bulkhead above the gearbox and these can sound as if they are coming from the wheel area.

[Busted Knuckle]

Also, there are a lot of potential leaks in the engine area including valves mounted on the bulkhead above the gearbox and these can sound as if they are coming from the wheel area.

Also there are valves & relays (air of course) around and above the axles too! FWIW   BK 

[Busted Knuckle]

AJ, one of the best investments I ever made was an Ultrasonic leak detector from the E-place.  Now, it wasn't necessarily for Freon, but it will detect an air leak as soft as you could blow.  It has a headset and a 9V powered wand with a volume control..  The neat thing about it is that you can tape it to a stick and sit back safe and not have to get under the bus while searching.  It's led me to a few I wouldn't have otherwise found with soapy water.

Mine was made by OTC Tools and is a big hit at rallies too.

NCbob

That's a great idea Bob ! Just tell SWWNBD (Yer sweetheart Jackie that is) that we don't have one, and don't have time to buy one and get it hear in time to here leaks at the RALLY! So's youse and hers needs to follow Uncle Fred opps NED and Wilma to the RALLY so we'll all be able to see how they work and if we gots air leaks! We'll leave the lights on for ya!   BK