Air bag replacement tips

Topic: Air bag replacement tips (Read 1487 times) previous topic - next topic

Air bag replacement tips

November 05, 2020, 10:58:29 pm

Ok. Bought 8 new bags, 3 new ride height complete valve kits and a rebuilt air pressure regulator. Going to have my repair shop do it. These guys have never done a FT. I purchased 8 Harbor freight 12 inch receivers to make it safe when I work under it. When they let it down on my blocks, can they still get the bags out once they dump the air with the 12 inch blocks in place? Should I just let them figure out a way or suggest they use these? Any order of replacement? When they go to adjust the valves to 8.5 inches on the bags at ride height, the blocks can't be in so what is a safe way to get under it? I read where the rear valves need adjusted first then the front one. Also use DOT teflon paste on all the air connections?
Any suggestions would be appreciated to help them get it right
Thanks

Re: Air bag replacement tips

Reply #1 – November 05, 2020, 11:04:27 pm

The rears can be done from the outside. Drive up on blocks to do the front.

Re: Air bag replacement tips

Reply #2 – November 06, 2020, 12:55:03 am

Dan it's a lot easier to pull wheels to change bags. More room. Also a great time to do brake caliper slide pin cleaning and inspection. Possibly add helper springs to calipers at that same time if they haven't been done. IMO
Scott

Re: Air bag replacement tips

Reply #3 – November 06, 2020, 11:12:18 am

As Dan said, it is way easier to pull the wheels and the job will go faster including pulling and replacing the wheels.

Re: Air bag replacement tips

Reply #4 – November 06, 2020, 11:42:24 am

If you do end up having them pull the wheels, I certainly agree about pulling and checking slide pins. Had a front wheel pulled to replace the seal, and they decided to pull the slide pin just in case after having visually inspected all of them. Significant pitting of that pin. Ended up having to replace all slide pins because of pitting and added helper springs just because. Pins are expensive, but you are saving some labor if wheels already off.

Re: Air bag replacement tips

Reply #5 – November 06, 2020, 12:32:53 pm

I've changed the bags on 2 coaches & it can be a much different experience on each individual coach. It's hard to generalize that one method or process is always better than another because the factory installation is different from one year to another, or from one coach to another. Many of the recommendations that I've seen would not have applied to my coach, and what worked best for my coach might not work for yours. I'm just saying, consider all of the advice but be aware that yours might be different and be prepared to adjust as needed.

Re: Air bag replacement tips

Reply #6 – November 06, 2020, 12:37:54 pm

Yes, good point bdale. Thanks

Re: Air bag replacement tips

Reply #7 – November 06, 2020, 01:05:47 pm

Quote from: dsd – November 06, 2020, 12:55:03 am

Dan it's a lot easier to pull wheels to change bags. More room. Also a great time to do brake caliper slide pin cleaning and inspection. Possibly add helper springs to calipers at that same time if they haven't been done. IMO
Scott

Ive got helper springs that need to be installed. Anything you or anyone else suggest to do at the same time as the helper spring install? Red tractor and Beau Reece both said my airbags and shocks are ok. My goal is to head to Alaska in summer of 2021 for a couple months.

Re: Air bag replacement tips

Reply #8 – November 06, 2020, 05:41:11 pm

OK, here are some photos of the air bag R&R on our coach. If you use an air/hydraulic jack to lift, there is no reason to remove the wheels as there is plenty of room to get the air bag in place and if the old bag is out and the plate clean, the new bag can be in place in 10 seconds without compressing it or anything. If the coach is not high enough, it becomes difficult and for no reason so get the up high. You will need to remove the fenders or make a special tool like I did for the four nuts with little working space. One of the other members one upped me with a tool like mine only with a ratchet box so it's much faster than mine. I did make a different safety stands as you can see. I would recommend starting the air fitting removal process before taking the bag off or you will have to find a vise or something to hold it. Use a tool that fits well on the brass fitting as you don't want to damage it. Vise Grips are a no-no. Loosen the fitting just a bit so you can easily take it off once the bag is out. I bought stainless nuts and washers as the new bags don't come with either. If you do decide to remove the rear wheels, make sure they are torqued correctly when you put them back on. So, with a 3/8" or 1/2' air impact and a couple of extensions, the 16 bottom nuts are no more than 5 seconds each to remove. The air stud nut is easy to remove leaving about 4 nuts (3/4" tool needed) that are difficult.

Pierce

Re: Air bag replacement tips

Reply #9 – November 06, 2020, 05:44:30 pm

Looks like two photos didn't load right.

Re: Air bag replacement tips

Reply #10 – November 06, 2020, 05:52:27 pm

Quote from: Pierce & Gaylie Stewart – November 06, 2020, 05:44:30 pm

Looks like two photos didn't load right.

The third photo in the first group is golden! I had thought about freeing the bag from the mounts, but not about getting it out of the cavity!

First photo in the second group. What is this used for?

Matt B

Re: Air bag replacement tips

Reply #11 – November 06, 2020, 06:08:24 pm

Thanks Matt! This photo didn't load correctly and I added (second photo) it to the second post. It shows the 20 ton air/hydraulic jack extended far enough to remove the bag. I adjust the safety stands a couple of times on the way up just to be safe. Both safety sands are used on each bag R&R.

I did one air bag after we bought the coach and had to put a knee on it to compress it, put the black vinyl cover back on the air stud so the bag could not expand, and lots of other things that made my blond hair turn grey (I wish). Air jack also makes changing tires a breeze for one person.

Putting the spare tire on: If you jack the coach until the tire is just slightly touching the ground, it's easy to work it back and forth until it's off. I try to raise the driver's side of the coach with the HWH so I can slide the spare out of the compartment and when it rotates at the edge of the compartment, the angle is easier to lift the high side and roll it into position.

Pierce

Re: Air bag replacement tips

Reply #12 – November 06, 2020, 07:11:18 pm

So if I understand...

The gray plate, thread and nut things are the safety stands. They would go between the frame and the axle carrier, parallel with the coach, to support the coach if the air jack were to fail.

Matt B

Re: Air bag replacement tips

Reply #13 – November 06, 2020, 07:21:21 pm

Quote from: dans96u295ft – November 05, 2020, 10:58:29 pm

Any suggestions would be appreciated to help them get it right
Thanks

Your 1996 U295 can't be much different than my 96 U270 only special tool was a willing and able partner. All eight bags without removing tires or fenders, rear bags were easy less than 30 mins. each.

Re: Air bag replacement tips

Reply #14 – November 06, 2020, 08:10:57 pm

Was wondering, If after you take off the Bag air line, you connect another line with shutoff valve and pull a vacuum on it and shut off the valve. will the bag stay collapsed for easier removal.? Just a question 'cause I have never done that job....yet.

Re: Air bag replacement tips

Reply #15 – November 06, 2020, 08:20:21 pm

A valve in the line won't work as it won't go through the mounting plate. BUT I use a brake bleeding hand vacuum pump with the tapered nozzle just stuck in the end of the air bag inlet. When bag is compressed then the 1/4" hose will feed through the mounting plate and keep the bag compressed.

So in short Yes

Mike

Re: Air bag replacement tips

Reply #16 – November 06, 2020, 08:24:56 pm

Quote from: master2301 – November 06, 2020, 08:10:57 pm

Was wondering, If after you take off the Bag air line, you connect another line with shutoff valve and pull a vacuum on it and shut off the valve. will the bag stay collapsed for easier removal.? Just a question 'cause I have never done that job....yet.

As you can see in my photos, there is no advantage to compressing the air bag. Once the fasteners are off at each end and the plate cleaned off of all the dirt, the old bag is out and the new one in place in seconds. It's not even hard. The only way to make the switch hard is to make the mistake of not raising the coach high enough. The point I'm making is that you can see with fully expanded bag in place, there are several inches above it so the clearance is huge.

Pierce

Re: Air bag replacement tips

Reply #17 – November 06, 2020, 08:32:51 pm

Tools

Re: Air bag replacement tips

Reply #18 – November 06, 2020, 11:13:54 pm

Quote from: dsd – November 06, 2020, 08:32:51 pm

Tools

Looks like you ground down the 3/4" to clear the 2"x3". Nice.

Pierce

Re: Air bag replacement tips

Reply #19 – November 07, 2020, 11:50:01 am

Actually the 3/4 clears. The 1 1/8 had to be thinned up on the end to clear tube. Also made a hat socket to go over air line fitting and use with 3/4 wrench. Makes it real easy
Scott

Re: Air bag replacement tips

Reply #20 – November 07, 2020, 12:43:00 pm

Quote from: dsd – November 07, 2020, 11:50:01 am

Actually the 3/4 clears. The 1 1/8 had to be thinned up on the end to clear tube. Also made a hat socket to go over air line fitting and use with 3/4 wrench. Makes it real easy
Scott

How about a photo of the "hat" socket? Picture is worth a thousand words. Are we talking about the small fitting the air line goes through or a socket to remove the brass fitting that goes into the hollow air supply stud in the air bag?

Thanks,

Pierce

Re: Air bag replacement tips

Reply #21 – November 07, 2020, 01:08:41 pm

Hopefully this is a more complete picture. Tape and die are 3/4-16. Not needed but there in no need for a friction lock on the big nut.. I put a drop of thread lock on it. Big size is 1 1/8 with end clearanced. Breaker bar make it work better than a ratchet.
Scott

Re: Air bag replacement tips

Reply #22 – November 07, 2020, 01:37:50 pm

I like the white tool for the air fitting. Good shot of all of them.

Pierce

Re: Air bag replacement tips

Reply #23 – November 07, 2020, 01:41:55 pm

Thanks, I'm just lazy
Scott

Re: Air bag replacement tips

Reply #24 – November 07, 2020, 05:26:38 pm

FYI

Not all bags are created equal. Some don't allow the coach raise to max. Not sure which ones. I would do the research if replacing with another brand.

The CONTITECH are fine

Chris

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