I have no idea what it is, what it's for, or what its called.
the device is described below. anyone who could help me ascertain its purpose I would really appreciate

there is a thin long metal rod that runs from the rear cross brace to a device of some kind which looks kind of like a brake proportioning valve. this device is mounted on top of the rear axle on the passenger side of the vehicle.

part of the problem with me finding out what this thing is is that its broken. their are two what look like hydraulic lines which run into it and were snipped off.

truck is a 90 4runner

thanks

 

that is exactly what it is is a rear break propotioning valve, its designed so that when there is more weight in the back the suspension compresses and applys more braking power to the rear wheels

 

thanks for the quick reply.

This may seem like a dumb question but I have been driving the truck for two years now and haven't noticed anything funny with the brakes under load or otherwise.

Is it necessary?
Because it is definitely broken.

 

it is necessary. brakes don't work to good without one. it helps the rears to slow the vehicle down before the fronts get full pressure. otherwise you could endo the vehicle. you do need this whether it's hooked to the axle bar or not

 

Thanks everyone.

If the device itself is broken and not just disconnected what would I call it when I tell the parts store I'm looking for another one?

rear brake proportioning valve?

 

I think its called the Load Sensing Proportioning Valve (LSPV)

 

razrwild nailed it.

lee