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T56-A-15 ENGINE OILS


airman57
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HELLO,EVERYBODY.

I WANT TO LEARN ABOUT C-130\'S ENGINES OIL (TECHNICAL INFORMATION) FROM YOU.

WE USE MIL-L-7808 ENGINE OIL FOR OUR T56-A-15 ENGINES.

T.O.1C-130B-1 SAYS MIL-L-23699 (AT NORMAL CONDITION)

BUT MAINTANACE T.O.SAYS MIL-L-23699 OR MIL-L-7808(BOTH)

WHICH TYPE OIL DO YOU USE? WHY?

WHAT DIFFERENCE?BETWEEN MIL-L-7808 ENGINE OILS AND MIL-L-23699 ENGINE OILS?

WHICH OF THEM IS GOOD FOR C-130\'S ENGINES?

WHICH TYPE OIL DO YOU USE IN USAF OR IN THE OTHER FOREIGN MILITARIES?WHY DO YOU USE MIL-L-23699 OR MIL-L-7808?

CAN YOU HELP ME? I NEED YOUR ADVISE.I WILL BE HAPPY.THANK YOU EVERYTHING.:)

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MIL-L-7808 is a mineral oil, while 23699 is synthetic, and therefore, never mixed under normal operating conditions. Unfortunately these

things do happen, and a simple hot drain and flush procedure within

10(?) flying hours can correct this. While the mil-spec numbers differ,

the performance of both types is consistant in terms of operating

conditions and results

Most operators turbo-jet and turbo-prop engines use Mobil Jet II, Castrol 5000 or O-156. In 20+ years of working RR-Allisons, Mobil

Jet II has been the oil of choice. It can take a real hammering of heat

and cold, and extended periods of operation without oil changes. Also, 2 years (or so) ago, the locals changed from O-156 to Jet II, and it

appears the number of filter changes for filter buttons popping has

dropped. Also after several hundred hours of operation, the Jet II

seems to be more slippery than the O-156 was.

For more detailed info on the oils, go to the Mobil, Shell websites

and call up the MIL-spec info

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I show Mil L 7808 as a syntehtic based oil.

LUBRICATING OIL, AIRCRAFT TURBINE ENGINE, SYNTHETIC BASE

4.4.3 Compatibility. The compatibility test shall be performed in accordance with FED-STD-791, Method 3403.

The lubricating oil shall be mixable with selected referee lubricating oils qualified under this specification, MIL-C-8188, and MIL-PRF-23699, without turbidity.

The USAF Job Guide only shows both oils for the APU. The GTC, ATM and motor only show Mil-L-23699 as supplies required.

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OK.THANK YOU VERY MUCH FOR INFORMATION.BUT................

WHAT DO YOU ADVISE FOR T56-A-15 ENGINES?

T.O.1C-130B-1 SAYS MIL-L-23699 (AT NORMAL OPERATING CONDITION)

BUT MAINTANACE USAF T.O\'s.SAY MIL-L-23699 OR MIL-L-7808(BOTH)FOR ENGINE,GTC,ATM.

WHAT WILL I DO?

WE HAVE MIL-L-23699 AND MIL-L-7808

WHICH ONE IS BETTER THAN FOR LUBRICATING?

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My last post went MIA ..... My apologies, 7808 is also synthetic.

In the 20+ years I\'ve been working Allisons, the only oil used has been

Mobil Jet II http://www.exxonmobil.com/Canada-English/Aviation/PDS/IOCAENAVIMOMobil_Jet_Oil_II.asp which is a 23699 oil.

Other turbojet and turboprop users may go for Castrol 5000, but I have

worked for a few places that dropped the Castrol in favour of Jet II

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THANKS PJVR99,PARROT,TINY CLARK

we have some reductıon gear box problems nowadays.

there is out of limits metal accumulation on our reduction gear box magnetic drain plugs.

And consequently,

we changed a lot of r/g boxes.

I doubt whether that our engıne\'s lubricating is insufficient.(MAYBE)

All in the same breath

(for once) we changed engine because of Accessory drive section magnetic drain plugs.

Before time as I were said,we use MIL-L-7808 OIL.

Therefore I doubt whether (our lubricating oil)(MIL-L-7808)

is it problem for lubricating?

What can I do now? I need your advise.thanks.good days.

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In The USCG we had foaming problems in the 90s that were finally proven to be caused by mixing 23699 from different manufacturers. We went to Mobil 254, but then with the \"J\" requiring Mobil Jet II, put all \"H\" and \"J\" on Mobil Jet II. Fewer problems, but you pay more.

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HI,PJVR99...AND OTHER GUYS...

IN GENERAL,WE SAW A LOT OF CHUNKS OF METAL ON MAGNETIC PLUGS.

SOMETIMES,WE SAW JUST FUZZ ON MAGNETIC PLUGS.

AVARAGE OPERATING TIME OF REDUCTION GEAR BOXES ARE 2000-2700 HOURS.

IS IT NORMAL?

WHAT OPERATING TIME ARE REDUCTION GEAR BOXES OF THE OTHER COUNTRIES?(AVERAGE)

MAYBE OUR OIL (MIL-L-7808)IS INSUFFICIENT FOR LUBRICATING.

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  • 2 weeks later...

It depends on the enviromental conditions you plan to operate in. The NATOPS list 23699 min operating temperature as -40c and 7808 as -54c. 23699 is primary and 7808 is alternate, but there are no additional limitations for its use.

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  • 1 year later...

The MIL-L-23699 has a higher flashpoint and higher viscosity at any given temperatures than MIL-L-7808.

MIL-L-23699 can be used in temps down to -40 deg's whereas MIL-L-7808 can be used down to -54.

I operate the T-56-14 in P-3C aircraft, which is the same engine as the Herc and all of our aircraft utilize MIL-L-23699. It really depends on your operating area and the climate of that area. Our ceiling is 32,000 ft and we've operated out of various cold areas, never had a problem with the 23699. Highly recommend the 23699, however, when and if you decide to convert, DO NOT MIX THEM! Drain/flush the 7808, including filters and run the 23699 through the system for 20 flight hours, then change it. You should be good to go from there. Have fun and keep'm on centerline!

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I remember 2 numbers from the 60,s.

Mil-7808 and I think there was a

Mil-5606. Was this 5606 hydraulic fluid

or a figment of my old imigination? Did it

even exist?

5606--That's the number I was trying to remember!!!! When I was a flare-kicker on Blind Bat, we sometimes used to take the chute out of the flare cannister and replace it with two cans of 5606 (at least that what I remember). Boy, did that ever make a nice ground-burner!! Or at least that's what we reported to the AC !

donwon, thanks for refreshing my memory,

Ken

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Had to stop using the stuff it was too corrosive especially for the landing gear struts!!

Really? Yours must be different than ours then. We still use 5606 in our aircraft, and we have found that 5606 is as good as CPC under the floor panels.

The USAF changed from 5606 to the currently used hydraulic fluid purely because of flash point. A prop leak that ends up in the brush block using 5606 sometimes catches fire. I guess the new hydraulic fluid won't do that?

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You are right on the flash point, but Air force did find 5606 corrosive when used in systems cleaned by PD680 dry cleaning fluid. This what I was told about when the conversion happened a while back to MIL-H-83282 then because this fluid did not work well in the low temperature range the perfered fluid was switched from MIL-H-83282 to MIL-H-87257 and all can be mixed with the previous fluid. The new fluid is a better fluid in preventing prop leaks in the winter; however, it is not perfect!

Really? Yours must be different than ours then. We still use 5606 in our aircraft, and we have found that 5606 is as good as CPC under the floor panels.

The USAF changed from 5606 to the currently used hydraulic fluid purely because of flash point. A prop leak that ends up in the brush block using 5606 sometimes catches fire. I guess the new hydraulic fluid won't do that?

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