In preparation to doing a R&R on my wheels this weekend I have been going over the Meritor brake info. I looked at Barry's extraordinary web site for answers. I viewed a photo album of Phil Bostrum removing his rear wheels for brake work. It appears that he is lifting his coach by placing the jack under the lower frame ahead of the wheel.
If I had not seen these pictures I would have thought that the coach would be lifted by a jack under the axle housing.
I can see that the frame position would be a easier jack placement point, but is this the best jack position? Front and rear?
Am I correct in thinking that I should place the frame supports(safety blocks) between the upper and lower frame, then dump the air bags before jacking? Chocking the rear wheel on the other side first.
I have 6 ton jack stands, is this too marginal for frame support in the rear or front? Would wood blocks under the frame or axle housing be a better stand than the jack stands?
Thanks for you advice!
Lon,
I assume you are referring to these pictures ? Brake Replacement (http://beamalarm.com/Documents/brake_replacement/brake_replacement.html)
I don't see anything wrong with how it's shown there. The jack point is off-centered but placing the jack under the air bag frames closest to the bulkhead should put the bulkhead joint in compression (good), verses placing the jack under the air bag frame that is farthest from the bulkhead would place the joint in tension (bad). You could lift the axle at the housing with a jack but then there's no space left for placing blocks under the axle housing. As you know you should not work under a jack alone. As an alternative I suppose you could put two stands under each of the air spring frames but they might get in the way of working. I didn't see it in the pictures but there should be chocks on the rear wheel on the other side of the coach as your first step. I would then release the parking brake and let the coach roll onto one the of chocks and then wedge the lose one up against the tire with a mallet. You don't wan the coach moving at all while torqueing on the lugs.
Yes, safety blocks (supports) are still needed but I would advise to keep the front axle air bags inflated so the front end of the coach can tilt as the rear is jacked up on one side. I have a manual air leveling system so I don't know if the HWH system will allow you to dump the rear and still leave the front inflated.
6 ton jacks: Fine for front axle on one side. Yes, right at margin for rear (assuming 20k on rear axle and stand inboard of wheels means it will have more than 50% of load). I would use wood blocks and 4x6's if you can - the ones in the pictures look a little unstable for being stacked so high. My advice is to always go the extra mile to make sure it is stable and secure.
Lon,
Unless it is nice flat concrete, I like using big blocks and 2x6s like John mentions. If the rig moves for any reason, it can't fall off the blocks. The longer the blocks, the better. They also soften the contact point.
A six ton jack may test your strength.
Pierce
Thanks for the help!
I have a 20ton air/hydro jack to lift the beast. I was referring to jack stands that are 6 ton rated. After reading your advice I will use the 4X6 suggestion and leave the jack stands in the garage.
We use a 20T hydraulic jack (not very big and easy to move around) with a dunnage pad on whatever surface (i prefer being in the shade wherever work is being done). Lifting hi enough to clear removing the tires (with a tire dolly BTW) and if you don't have a dolly "be cautious with big ass wheels". This is an excellent time and place for back problems that will haunt you until the end of your days. Brake jobs are a piece of cake, just be friends with a gorilla to help move the wheels around. pc
Here's a creative solution one of our members came up with
Redneck tire handler (http://www.foreforums.com/index.php?topic=16300.0)
Red Necks Indeed, this neck uses one similar to the pix. As one ages, it is much nicer to use the long handle to position the jack exactly where you want it with out crawling under it.