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1986 Unimog U1300L
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435 Posts
Discussion Starter · #1 ·
Hi,
I got switches where the gear levers are and I can't figure out what they are for....

(1) - I can pull out to about 3 inches, but it doesn't seem to make any difference
(2) - is a momentary dial, if I turn it 90degrees I can hear air releasing

Do you know what they are?

2650522

2650523
 

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U1450L DOKA
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17,567 Posts
No.1 looks like the Start Pilot pump.
It is missing the knob.
You can pump it up and down like a bicycle pump, to give a shot or two of ether into the intake circuit for cold weather starting.
 

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U1450L DOKA
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No. 2, I believe, is the Diff lock-
Should be 3 positions -
2 Drive
4 Wheel Drive
4 Wheel Drive, Diffs locked

I have a civilian truck, so my switch is on the dash, but I ‘Think’ that Military Unimogs had them on the shift plate for a while.

If you don’t know which position is which, when in 4WD Locked, your turning radius will increase substantially.
 

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U1450L DOKA
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I’m not so sure about No 2.
While that is a position where the Diff Lock switch was placed on Civilian and Military trucks, the shape of the knob was usually different - either a lever, like the dash version, or a daisy shaped knob with a pointer molded into it.

Sometimes a PTO switch had the shape shown, and a U1300L with a winch would have something like that.
However, peering at the sticker by your switch, I think I can make out
“Emergency Release”.

I don’t know the military trucks very well, and.... I’m rusty.
 

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1986 Unimog U1300L
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435 Posts
Discussion Starter · #6 ·
My Diff lock switch is on the dash.
I tested (2), and yes it releases the park brake momentarily.
For (1) to work, I guess it would need an ether bottle somewhere? I think its not connected, but I crawl underneath and have a look - not that I would be concerned about cold start here in tropical Darwin ;)
 

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1990 Unimog U1200, 1989 Unimog u1200, 1971 Unimog 421, 1978 Case MB4/94, 1963 Land rover Series IIa,
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66 Posts
Number two is used for engaging or disengaging an air actuated dog like a high-volume hydraulic pump. Mine has that mounted on the rear Of the drivetrain case and is used to actuate a hydraulic pump for a sweeper.
 

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U1450L DOKA
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Ah....good, but the “Emergency Release” would not seem to relate to powering up a sweeper.

As far as the start pilot, you won’t have to crawl under the truck.

If the system is intact, there will be a fill port on the front end of the engine, usually on the right hand side (LHD vehicle, at least).

It has a triangular shaped plastic cap, that is spring loaded.

You open the cap and charge the system with an aerosol can, specific to Mercedes Benz, more or less.

Less expensive cans of ether have been tried with varying degrees of success.
 

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U1450L DOKA
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After reviewing the photos, I’d like to correct my previous statement regarding the “Triangular “ cap.

The cap is actually circular, and the plan view of the receptacle is roughly triangular .

It looks like an egg hanging off the side of the engine - the reservoir below the fill port being translucent white plastic.
 
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