Jacking up gmpd4106

[Fred Mc]

What is the best way to jack up? A 4106 in order to remove the wheels to replace a rear airbag?

[dtcerrato]

On our 4104 I use the rear bulkhead just forward of the rear axle and if along side the hwy changing rear airbag is much easier with that set of duals off. BTDT multiple times in 44 years.

[Fred Mc]

If you put the jack under that bulkhead, can you raise the bus enough to get the wheels off given that the axle and wheels will want to  droop or do you need to use a second jack to jack up the axle?

[Nova Eona]

Second jack for the axle - at no time should the axle/wheels be hanging in the air without support from below.  This isn't a car where you can schlep the whole thing into the air on a single jack, every component involved here is monstrously heavy and airbags are made for compression loads, not tension.

Oh, and cribbing.  Anything you can do to reduce the chances of the bus slipping off a jack (or a jack failing) and finding nothing harder than you to stop it from reaching the ground.

[dtcerrato]

If you put the jack under that bulkhead, can you raise the bus enough to get the wheels off given that the axle and wheels will want to  droop or do you need to use a second jack to jack up the axle?

What Nova Eona said but I'd like to elaborate.
If you're on solid stable ground or better yet asphalt or concrete with the bus ride height fully up place good solid dependable blocking under the rear bulkhead on both sides. I use small steel plate between the bulkhead and the blocking so as not to point load the blocking. Purge all the air from the suspension until the bags go soft - the front will drop the back will sit solid on the blocking now you can put a jack under the back axle of the side you want to work, the jack.can be a small one ton because it's just lifting the axle end to remove the tires. Block the axle so as not to depend on the jack. Air bellows are now ready to remove. If the bellows bolts are rusty it would help if you soak them in penetrating rust buster for easier removal. This is a personal short cut way, two jacks could also be used and following the criteria Nova Eona explains, HTH.

[Jim Blackwood]

Be somewhat wary of blacktop. To this day I remember my brother coming in and dropping his trailer on the driveway, laying an oak 4x4 across under the landing gear. Next morning the trailer was on the ground, two holes punched through the blacktop with pieces of 4x4 sticking out.

Jim

[Fred Mc]

Is it necessary to get under the bus to change a leveling valve or can this be done with the wheels off?

[freds]

Is it necessary to get under the bus to change a leveling valve or can this be done with the wheels off?

Not sure of your bus, but wheels seems to give access from most pictures of buses that I have seen.

[epretot]

Does anyone have a video training of this?

[dtcerrato]

It is possible to get to the rear leveling valves on early GM models without the tires on and blocks between the axle & bumpstop and axle & ground but workable space is tight. I love our pit.