1970 rear backing plates

[aeromech]

It seems unusal that the engines would leak like that. I think that the C130 had turboprops on it and unlike the earlier radial engines from WWII era, modern turboprops normally run pretty clean. They usually don't have large oil tanks either so a sizeable leak would make me worry. On the airplanes I worked on we had leak limits in the maintenance manual. A drive pad for something like a starter or hydraulic pump could leak about 10 drops a minute max before you'd have to fix it. Another thing about the C130 is that they were pretty long haul aircraft so a leak like that would be a problem on a flight from Panama to the US I would think. All that said, I guess you lived through it.
_________________
Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound

[rockerarm]

Boy oh boy, it only gets better. My "customer" returns back to Jacks in wilmington with this used drum from Goldmine. They proceed to tell him its the wrong drum, that he needs the "G" drum. They trial install onto the lt rr and it hits/rubs on the backing plate. I am not sure if this is a case of the spacer wear causing the drum to sit closer to the backing plate or there are diff drums out there for the drum brake bay. I may get that spacer for this bus, aeromech!
Bill

[Desertbusman]

Evidently new drums not configurated or designed to mate with stock backing plates are not that uncommon. It gets mentioned here once in a while.
_________________
71 Superbug
71 Westy

[rockerarm]

So, desertbusman, is there one backing plate and one drum for '68-'70 bay's? And is it just a quality control issue with the aftermarket drums? Do you feel that it may just be a matter of chucking these brake drums into a brake lathe and giving the outer lip a little trim?
I would appreciate your feedback, thx, Bill.

[SGKent]

rockerarm. The person to ask on this may be Colin as he indicates he has seen the spacer wear which allows the drum to be close to the backing plate. I have such a situation on my 1977 bay where the drum rubs but I am beginning to suspect that the spacer is worn or one of the surfaces that touch it.
_________________
Canned Water - the new California approved parts cleaner (except in a drought in which case rub it with sand).

George Carlin:
"Most people don't know what they're doing, and a lot of them are really good at it."

Skills@EuroCarsPlus:
"never time to do it right but always time to do it twice"

[aeromech]

Wow, I had no idea that this would blow up like it has. I'm hoping that tomorrow I'll have my shims completed. Once I do I'll post pics.

Bill, as far as I know there are no aftermarket drums for the 1970 bus. As far as I know. The drums I just installed came from a junk yard with VW stamped into them. I don't know why they seem to rub the backing plates but I'm pretty sure the shims will stop that. We'll see in the next week or so when I get the bus back.

Right rear

Left rear

New backing plate and drum l/r

_________________
Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound

[rockerarm]

SG, I agree. It amazes me this issue hasn't happened, to this extent, a decade ago. The contact area on the spacer is so small, in my opinion, that it was only time before this happened. Bill

[Desertbusman]

[SGKent]

[aeromech]

This is getting interesting.
_________________
Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound

[rockerarm]

[SGKent]

on my 1977 there is an actual spacer. 14 EU each so I ordered 2 from Germany about 5 minutes ago. I next need to find a new stub axle and flange for each wheel and we will settle this once and for all on my 1977. Will post back how it turns out.
_________________
Canned Water - the new California approved parts cleaner (except in a drought in which case rub it with sand).

George Carlin:
"Most people don't know what they're doing, and a lot of them are really good at it."

Skills@EuroCarsPlus:
"never time to do it right but always time to do it twice"

[Desertbusman]

Up to '70 there is a spacer ring and also the spacer sleeve. Also throw in the roller bearing. So the total stack up of length could be a problem. Such as a new bearing that is different. As far as that goes even a wierdo inner bearing would affect it. And there is a different setup starting with '71 with only the sleeve. So if someone ran into the problem after they serviced the rear bearings it might be more involved than the hub or the drum.
Something else. If the relationship between the drum and backing plate has a problem it would also affect where the shoes contact inside the drum. Wonder how that checks out.
Unless any new parts were put in that were different than original it seems like the only way the spacer or ring would get shortened by wear is if the drum (or hub) were put on loose or one of the bearings froze and spun.
Bill, the original drum didn't have a problem against the backing plate but the new one did? Was the original one worn down or are the two drums different? Sure seems like people have talked about drums being different at that inner ring portion.
Hope you guys figure out the cause,
_________________
71 Superbug
71 Westy

[Tom Powell]

[aeromech]

You crack me up Tom. In aviation they use so many abbreviations to descibe things that it's almost like speaking a different language. For instance one guy might say to the other "the APU EGT is on MEL" Most people wouldn't have a clue but I'll bet Tom knows what that means.
_________________
Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound

[Tom Powell]

[SGKent]

which is precisely why a 727 went into the ocean off Santa Monica back in 1969. The APU wasn't operable.

The 727 took off with a failed alternator because the APU wasn't operable. Both main alternators were so the flight was legal - except that about 9 minutes into the flight one of the engines went whacko so shutting it down also shut down one of the main alternators. The plane had to fly on one engine hence one alternator and no backup from the APU for teh cockpit. While everyone on the crew was scrambling to turn the plane around and take it back to LAX, the alternator bus blew as the single alternator could not carry the load - oops someone forgot to turn off the cabin lights? So now we have no power. no electronics and no horizon over the ocean in the middle of a storm out over Santa Monica Bay.... The plane did not make it back to LAX.

So maybe the APU should work before you leave - eh Tom?

now back to the backing plate story...........

Gary - did you have that spacer and the other part Mike referred to in his post?
_________________
Canned Water - the new California approved parts cleaner (except in a drought in which case rub it with sand).

George Carlin:
"Most people don't know what they're doing, and a lot of them are really good at it."

Skills@EuroCarsPlus:
"never time to do it right but always time to do it twice"

[aeromech]

Okay, My buddy used the water jet to cut me 10 shims out of 1/8 inch Hast X

http://www.haynesintl.com/pdf/h3009.pdf

Steve, I know you can't view the pic, sorry. I had him make a few extra because I thought my samba buddies might need some too.

I'm not aware of that 727 crash you speak of. Which carrier was it? Oh, bye the way. In my experience MOST commerical jets flying have at least one item on MEL. They put a big orange sticker on the log book cover and I've seen some log books where they looked like wallpaper.
_________________
Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound

[SGKent]

[Tom Powell]

[quoteFlight Rules="SGKent"] ...
So maybe the APU should work before you leave - eh Tom? ... [/quote]

Absolutely in some scenarios.
The MEL lists the conditions under which the MX can be deferred. i.e. No APU may be required if the flight is below 10.000, (the APU will not be required for emergency pressurization), less than twenty minutes to destination (30 minutes battery only operation is available at reduced electrical load), VFR (visual flight rules) from departure to destination from ETA to ETA+30 minutes.

I browsed the 727 accident near LAX
http://aviation-safety.net/database/record.php?id=19690118-0
PROBABLE CAUSE: "The loss of attitude orientation during a night, instrument departure in which all attitude instruments were disabled by loss of electrical power. The Board has been unable to determine (a) why all generator power was lost or (b) why the standby electrical power system either was not activated or failed to function."

An APU would probably not be required in most electrical scenarios for a 727, But that accident might not have happened if the APU was operable. Airplanes, VW's, and life are about risk management.

Aloha
tp