Troubleshooting big air brake leak

[dtcerrato]

Just one of many many big corps that created that concept...

[Nova Eona]

Well gang, I have decided to hang onto my old chambers - I'll set them  aside for a rebuild sometime when I have fewer critical things to work on, and they can reunite with the bus when and if I have any issues with the Chinese chambers.

That said, I'm very glad I'm doing this - correct me if I'm mistaken, but the below angle looks quite wrong for these, my understanding is the angle with brakes applied should never be greater than 90:


Above is the driver side (which started leaking while I was working on them today), while below is the new can on the passenger side which I had cut down to match the take-off, then cut down a bit more today:


Right now my plan is to take another inch off the rod on the passenger side, then cut the new driver side chamber to match it, with the goal of getting down to that 90 degree angle point.  Let me know if I'm missing something here.

[DoubleEagle]

Well, yes, the horrible cracks in your tire(s). They look like they might blow any minute. I would not take them on the road. Replace! 

[Nova Eona]

Oh I'm well aware of those - I'm fixing the brakes now so I can creep slowly down to the local tire shop, those tires are 21 years old.

[DoubleEagle]

That would put them in the three digit DOT code area. Some shops would be very scared to work with them with pressure still in. Don't linger near them, the shrapnel would hurt. 

[chessie4905]

Are those tubeless tires?

[Nova Eona]

Nah, they're radials, just ones old enough to drink.  Date code 118, which means they actually had a birthday this month and are now 22.  Once I get the brakes squared I'm going to slowly head over to a tire place nearby to get some fresh rubber on; it's a bit tempting to just pull the front wheels and take them in to get replaced first, but I don't have a concrete or paved surface to block up on and I don't trust the ground this time of year.

[Jim Eh.]

Sometime you have to know how it is supposed to be done and not to just depend on how it was done. Looks good.

[chessie4905]

Yes radials but is the tire diameter 20" or 22.5? In other words one piece rims or split rims with lock rings?

[Nova Eona]

One piece budds, 24.5" - they're old but not ancient.

[chessie4905]

Thats good. There are still 4104's around with the old split rims. Glad you dont have to find new wheels.

[windtrader]

I've seen that happen before, where one factory produced goods for multiple companies in the US.

When searching for parts online, I'll often see 3 or 4 brands with identical parts with nothing different except the label. But when looking further see that there are different specs, different item weight, etc.

Without breaking down the cans to examine the components inside, there is no way to determine if they are identical through and through or if there are variations inside.

Likely they are the same, and it's often difficult to determine which one is better (if any).

Back in the 60s and 70s my grandmother was the accountant for a top-tier handbag company in New York. I remember her telling me that they sold only first-quality goods - no seconds or other lessor goods. But, she said, the first-quality goods they sold to Neiman Marcus were substantially better than the first-quality goods sold to Macy's. On the outside they may look identical, but she said there were many differences that could not be seen. Since she was their bean counter, I'm pretty sure she knew all the details of the differences.

Ever since that talk/lecture from her, I've always inspected the quality of goods beyond the surface & labels.

Even if the product is exactly the same, from the same production batch, what happens is the first quality units go to the contracts with brand name companies. Those not passing QA go to lower tier contracts and the rest, the stuff we typically call chinese crap, gets a whatever label and sold off cheap.

[Nova Eona]

Thats good. There are still 4104's around with the old split rims. Glad you dont have to find new wheels.

Me too!  Got the new chambers' rods cut down today, mounted, and adjusted for a 90 degree angle.  Adjusted the slacks and greased all the zerks while I was down there, time for new tires finally!