Making Unimog meet American DOT/EPA emissions regulations?

[dzzz]

If you ever wanted to live in California and register such a vehicle here, the additional requirement would be a need to pass smog testing on any vehicle newer than 1975. Diesels have been exempted, but I believe they are trying to put some limits on them as well. Furthermore you need to have a commercial drivers' license if the weight is above a certain limit and/or it has air brakes. If it is registered as a motor home, some of those requirements might be different. If it was a fire truck in Europe, you may also be able to bypass some importation regulations.

Cheers,
Greg

In California and other places it's important to distinguish between the age of the Unimogs. The newer U500 would need a smog retrofit to operate as a commercial vehicle. Which is a problem since no one has designed a smog retrofit for the truck.
I'm not sure what U500 RV owners in Cali believe will happen with their vehicles in the future.
Some people claim there is no state that requires a CDL on airbrakes as long as it's RV registered. I have enough problems figuring out my own state to worry about the other 49.

 

[rshimizu12]

Is it possible to convert the air brakes to hydraulic....?

 

[Iain_U1250]

Is it possible to convert the air brakes to hydraulic....?

Unimog brakes are hydraulic/air hybrid. Air line to the brake booster, but hydraulic to the brake calipers. The emergency brake is spring applied/ air release. It should be possible to convert to hydraulic setup, with a remote booster, but may require a different master cylinder given the dual calipers on the wheels, and the air booster creates a massive amount of force on the master cylinder compared to a normal vacuum booster. Everything is do-able, but it is not a simple as swapping out a car vacuum boost system into the truck. There is a chart of the hydraulic pressure on the standard Unimog brake system somewhere, so finding something that produces the same amount of pressure would be a start.

 

[charlieaarons]

Actually U500 brakes, and also newer U5000s (5023s), and the U3xx and U4xx etc are pure air brakes - no hydraulic at all.
I cannot conceive of any rational reason why a person would want to convert any Unimog from either pure air brakes or the older air over hydraulic system.
There’s several features that make air brakes of either sort vastly superior to hydraulic brakes.