Check this video out . It will explain: kzbin.info/www/bejne/nZrcnauPbtmHrpIsi=SE_S5uOcBM5sMBXn

This grinder was never serviced so it was all from the manufacture it just was used very heavily and the operator did not stop grinding even when the brushes needed to be replaced.

This was purchased new from Hilti and was heavily used without replacing the brushes when they needed it. It was abused beyond what it should have been. Not a problem with the manufacture but the user.

They dont work as well as a air full air system, as they require more maintenance on mechanical parts .. but air is lousy if an air line blows in a bush fire (trailer stuck) Hydraulics in steel lines can take a bit more heat than rubber or plastic lines .. Master and Slave Cylinders 'like to be used' so dont leave them inactive to rust or corrode ..

Hey there, Steve, I have the same lathe so I can tell you that yes, the thermistor is an NTC 3D-20 rated 3 ohms at 8 amps.

Timing chain was “stretched” . Worn chain and tensioner. It happened again after I had it fixed at 99,000 miles. I ended up trading it in on a F250

It has been a really long time since I was deep into understanding these systems however if you have a leak and it isn’t that bad the reservoir should be able to maintain the air pressure to use the brakes. And as long as the red glad hand is still connected and their is air pressure to the relay from the red glad hand the trailer will not divert air to the brakes even if the yellow glad hand is disconnected or has a massive air leak allowing you to tow still however the brakes will not function. If the leak is really bad on the trucks system, the red glad hand or there is a loss of air pressure such as a break away the air pressure relay will divert air from the reservoir to apply the brakes “ON” . The brakes will stay applied until the air pressure is released (tank drained) or the glad hand / service air is restored. A loss of air pressure or break away will not lock the wheels like modern air brakes but it will lock the shoes to the drum in the fully applied position. I hope that helps explain it a little better. The breakaway principle is the same as on modern electric brake trailers. When the breakaway cable is pulled from the relay box the relay sends the signal to apply the brakes and is powered by a small 12v battery. Once that battery power is depleted the brakes will release. The same goes for the air over hydraulic. When the red glad hand is disconnected in an emergency break away situation or there is a loss of air pressure to that air line, the air relay applies full pressure from the air reservoir to the hydraulic system which applies these brake shoes to the drums and will continue to do so until service air is restored or the air in the system is depleted.

You can retrofit a surge brake system to this and it will work. The cost is relatively similar to other systems however if you already have the parts then that’s a win!

Yup. The loss of pressure when the red glad hand is removed or cut causes the emergency relay to apply all reservoir pressure to the system and apply the brakes. If the trailer is in good condition the air system becomes a closed loop at that point and will not release the brakes until the air system is drained or proper air pressure is applied to the red glad hand again.

@@SmokeyJa I guess no need for big danger springs that way, but seems a spring-applied system is safer operationally.

@@StefanBacon not really. This system is really safe as well and works similar to electric brakes. When the relay is actuated by removal of the breakaway cable 12v aux power is sent to the brakes and holds pressure. The same with the air. When the air pressure is lost by the red glad hand breaking away the relay actuates and puts air to the hydraulics which puts the brakes on. It’s a closed system at that point so the air is trapped and the brakes are on until pressure is applied to the relay or air has been release from the system. You wouldn’t want to be stuck out in a war zone with your emergency trailer brakes stuck! I like that both electric and this air system can be bypassed to still tow the trailers.

Just put it in neutral and turn the hub.

Thank you for the comment. It makes it worth it knowing it helped. I’m about to do a complete brake swap video in the next few weeks.

Haha well that sounds frustrating! I am glad this video could help you identify that and you’ve been able to make it now work. I use KZbin videos a lot to help quickly find out information. Thank you for commenting !