| Author | Message | ||
| Jim Schrecengost (Schrec)
Registered Member Username: Schrec Post Number: 85 Registered: 2-2007 Posted From: 24.2.127.94 Rating: N/A |
First I have a 1963 4106. The "front" rear air bag on the passenger side is leaking around the top where it connects to the beam. Does this call for a complete bag replacement?????? is there something I can do to tighten this. It will take about a day before she is squating on that side. The airbags where recently replaced by the PO. Any help would be appriciated! Jim | ||
| Len Silva (Lsilva)
Registered Member Username: Lsilva Post Number: 212 Registered: 12-2000 Posted From: 24.164.20.23  Rating: N/A |
Since you don't know the quality of workmanship by the PO, I would suggest removing the bag and thoroughly cleaning the mounting flange. They probably left some crud on there. | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 846 Registered: 11-2005 Posted From: 208.54.200.21 Rating: N/A |
Bag replacement depends on the bag condition. It may be rotted out but leaks usually happen because the plys separate. No way to know for sure until you remove the bolts nuts and bag end. You don't need to remove the whole bag. Before letting all the air out of the bags be sure to block between the rubber bumper and suspension to give you space to work. If the metal sealing surface is corrosion pitted you can probably seal it with any good sealer. I've seen it done with silicone seal. This area usually seals pretty well and, as posted above, there may be some trapped crud. There is always the possibility that the bolts were overtightened which could warp the rubber sealing surface. | ||
| Jack Conrad (Jackconrad)
Registered Member Username: Jackconrad Post Number: 993 Registered: 12-2000 Posted From: 71.54.29.215  Rating: N/A |
I don't think the 4106 used the air beams, they used rolling lobe air bags. I think they were a sealed rolling lobe bag. You will probably have to replace the complete rolling lobe air bag. Jack | ||
| Bill Gerrie (Bill_gerrie)
Registered Member Username: Bill_gerrie Post Number: 241 Registered: 3-2006 Posted From: 216.198.139.38 Rating: N/A |
Jim If you look in the parts or service manual you will see a round metal plate at the top of the air bag with 2 mounting bolts. One has a hole through it for the air line. It could be the PO replaced the air bag but not the metal plate that seals the top of the bag. You will have to remove the bag to see if this is the case. The nuts that hold the plate are a thin metal stamping so they should remove easily. The air bag is dated so you can see the date of mfg on it. Follow Gus's warning about blocking everything before letting the air out and you getting underneath. Bill | ||
| Jim Schrecengost (Schrec)
Registered Member Username: Schrec Post Number: 86 Registered: 2-2007 Posted From: 24.2.127.94 Rating: N/A |
Bill - I did see the book showing how to disassemble. was hoping i didn't need to. Anyhow where exactly should I be blocking. I have a huge amount of respect for this 12 ton thing and dont want to be flattened!!!! Jim | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 1371 Registered: 10-2003 Posted From: 71.58.110.9  Rating: N/A |
The rolling lobe units that the 4905 uses that were separate parts like, I think yours are, were replaced by a complete unit. I think the old type were Firestone type. The new ones replaced the old design and probably cost less than the old units. Mohawk sell them, along with other vendors. | ||
| Clint Hunter (Truthhunter)
Registered Member Username: Truthhunter Post Number: 82 Registered: 1-2009 Posted From: 24.129.235.190  Rating: N/A |
No experience on a GM coach air bag, but I have seen plates leaking past the ring through a cracked plate and sometimes galvanic corrosion when steel and aluminum touched. Left alone they would of only got worse and perhaps left the coach disabled. The only way I would have known was disassembly in these cases as the "soap to find the leak trick" indicated it was under the bead clamp. If your style was such and the bolts had not yet corroded beyond re-torque , then Perhaps try that after leak testing, but you might make it worse by disturbing the leak. I had once considered a short term patch that might work using tire sealant ; but again you take's your chances , but if the sealant gets into the level valve, you got more problems and it is time to do a complete job. Get in there with a spray bottle of soap, light & mirrors to find & asses all the leaks first, including the air line, connections and leveling valve. | ||
| don goldsmith (Bottomacher)
Registered Member Username: Bottomacher Post Number: 242 Registered: 12-2000 Posted From: 72.15.86.59 Rating: N/A |
Jack is right. I watched the mechanic replace the front bags, and I know that they are a sealed unit. They came from Luke's shelf a week before they were installed, so I don't doubt the quality.There may be a hole caused by a flake of rust or other chafe. The installation process was pretty quick and simple as I recall, unlike the rear bags. Have you checked for a leak in the air line or fitting? I would, before removing the bag. | ||
| Bill Gerrie (Bill_gerrie)
Registered Member Username: Bill_gerrie Post Number: 242 Registered: 3-2006 Posted From: 216.198.139.38 Rating: N/A |
Jim You want to support the body weight between the axle and the subframe. You can also put wooden suports under the body jacking pads. Just make sure it is solid and don't use concrete blocks. They can crumble too easy. There isn't enough room under the body for you if it suddenly comes down. Be safe. Bill | ||
| Jim Schrecengost (Schrec)
Registered Member Username: Schrec Post Number: 87 Registered: 2-2007 Posted From: 24.2.127.94 Rating: N/A |
I did the soap trick and it is the bag itself. Let me restate that this is on the rear axle, passenger side but the front of the two bags. I guess I will just go out and take it apart and see what happens??? Jim | ||
| don goldsmith (Bottomacher)
Registered Member Username: Bottomacher Post Number: 243 Registered: 12-2000 Posted From: 72.15.86.59 Rating: N/A |
I misread your first post. The rear bags have not been replaced. | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 847 Registered: 11-2005 Posted From: 208.54.200.187 Rating: N/A |
Jack is right, I forgot the 4106 has a different airbag, sorry about that. | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 1375 Registered: 10-2003 Posted From: 71.58.110.9 Rating: N/A |
Once it is blocked up properly, inspect the condition of all four bags. If they are original and or in suspect condition with even any small cracks and rolling lobe type bags, now would be the time to replace all four with complete units; they aren't that hard to do compared to the ones on the 4104 or the multipiece old style rolling lobe units. BTW, after coach is PROPERLY BLOCKED UP and before you start working near those bags, you should exhaust most of the air from all four bags. You can do this by disconnecting link from leveling units and move lever to exhaust the air from the bags. If one of those would blow while working on them, the noise would deafen you, possibly permanently besides injury from the force of the rupture. You should have a copy of da book before beginning. | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 850 Registered: 11-2005 Posted From: 208.54.200.131 Rating: N/A |
I don't know if it applies to the 4106 but the 4104 replacement bags are not the same as the original ones. They also use different bolts, the heads are different. If you're anywhere near OKC call Jefferson Bus and ask for Ed for great service and reasonable prices. Ed knows his buses. | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 1379 Registered: 10-2003 Posted From: 71.58.110.9 Rating: N/A |
4104s use bags with several bolts and rings at both ends. Somewhat a pita to replace. Rolling lobe one piece units are pretty easy to replace; just one or two large bolts at each end. | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 851 Registered: 11-2005 Posted From: 208.54.200.68 Rating: N/A |
John, You're surely right that the 4104 bags are a pita! I wish you hadn't told me how easy the others are because I still have the four rear to go!! I thought they were all about the same amount of work. I think the 4104 has something like 9-11 bolts in each ring and they are a real pain to get lined up with the ring holes. | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 1380 Registered: 10-2003 Posted From: 71.58.110.9 Rating: N/A |
I replaced a rear one a couple of years ago without removing the wheels; really made it difficult to reach some of the bolts. Don't screw around trying to reuse them, get all new ones. If you install the beam plates, which you probably should do while you are at it, since the beams will start leaking sooner or later, you will need the longer version of the special bolts. Use anti-seize on the threads | ||
| Frank Allen (Frank66)
Registered Member Username: Frank66 Post Number: 107 Registered: 10-2005 Posted From: 205.188.116.203 Rating: N/A |
there are no air beams on a 06, usually the metal plate on top of the bag rusts out, they are not hard to replace on front and you dont need to take wheels off, last one i bought was just over 100.00 from luke, thats what i would do, replace the leaking bag. no big deal Frank allen 4106 | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 891 Registered: 11-2005 Posted From: 208.54.200.93  Rating: N/A |
Jim, I just realized how this thread is. Did you replace the bags? If you haven't; there is a rubber "bottoming bumper" that keeps the suspension metal parts from contacting. Use a good hardwood block, this is usually about 3-5", (you need to measure it with the bags inflated) between that rubber bumper and the opposite member. This allows the sir bag to deflate without the bus lowering. This makes it much easier to insert the new bag. Let us know what you did or are going to do. | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 687 Registered: 7-2006 Posted From: 70.212.130.64 Rating: N/A |
Gus ....is that exclusive to the GM's or is that..."in general"? Thanx, RCB | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 1451 Registered: 10-2003 Posted From: 71.58.110.9 Rating: N/A |
I was replying to Gus; the 4106 owners are fortunate in that they have the new style bags, and are simple to replace.In the 4905 manual they recommend to find a section of pipe that has an inside diameter that will fit over the round bumper stops. for differential removal, they call for 10 inch long pieces, although 6 or 8 inch would do for everything else. Disconnect the leveling valve arm and raise the coach to allow insertion of pipe or heavy wall tubing, then lower suspension to rest on spacers. |