Search results

The PCU uses pilot operated valving. The solenoids control a small amount of air to shift the valve cores in the manifold. So you have seals in the solenoid valve and seals in the core. It could be a seal on a solenoid valve, or the seals on the control core are leaking a little…

No that vent should not be venting until the control solenoid is released… yes the PCU can be disassembled to access the valve cores. They seal with Orings and I believe Superman has spare valve cores…

Have you checked your axle vents? An axle seal will vent air into the axles which will escape thru the axle vent…

Well if the pressure is dropping, then you have a leak:) I think the controller pauses and looks for this pressure stability as a way to diagnose leaks. With control closed and a shot of air to pressurize the system it should be able to set there all day. For a given size hole, the greater the...

I believe It is normal, at least the two I have played with now do it also Even after new valve cores. The supply does(should) not leak when control is de-energized. The solenoid valves in the PCU are pilot actuated and they may be plumbed to deliberately interact this way. (Would alert you to...

Which mirrors did you go with?

I would think it is supposed to accurately reflect switch state, so either the controller is mis-reading the switch circuit or there is a problem with the switch circuit causing it. I would ring out that circuit really well. An ohm meter will tell you if you have a good circuit by jumpering...

but it continues to short cycle with the switch unplugged? Either the switch sense circuit is not working(bad controller) or perhaps there is a low resistance path in the wiring back to the switch… The tester gives you switch state to see if it is cycling properly with manual operation and...

Ok, on the A1 they tapped off brake switch power directly to feed the trailer plug, which bypasses all the other wiring. It is the same brake power that activates K10 When you step on the pedal. One of the reasons I like to concentrate on one problem when there are multiples is that in fixing...

Thats weird. Just to clarify, pressure switch(wet tank) or pressure sensor(on PCU)? If the switch circuit was shorted somewhere along the path from controller connector to wet tank. That would lie to the controller and it would allow it to try and function. The wet tank switch tells the...

What do the primary and secondary brake gauges read when the dryer purges? It should be 125PSI, and the wet tank switch should close above 117… you should be able to measure this closure between two of the 3 pins on the pressure switch connector. Two of those codes you listed indicate a bad...

As long as the relay is going click along with that green LED… On the A1, Power From CB71 passes thru the energized contacts of K10, thru the steering column switch and thru the DE-ENERGIZED(pin 87A-30) contacts of K21 and K22 (left and right rear light relays) And on to the rear lights. The...

So when you step on the brake pedal does K10 energize?

On the A0, they ran the bypass coolant from the thermostat housing down to a port on the left of the trans heat exchanger, and that is exactly what it does, it dumps all the engine heat into the transmission until it warms up(horrible way to run a diesel). They did away with this “feature” on...

I found it with a search, It was Ramdough and we were discussing new hose lengths for his cooler relocation back by the axles. Here is a pic of the unit in question Located right behind the transmission...

On the 4 wheelers, the trans fluid flows forward thru a heat exchanger on the lower radiator pipe, dumping its heat into the coolant that is headed back towards the engine. The cooled trans fluid then flows back to the trans. Basically the same as any automatic trans pickup… On the units with...

The 1089 has a liquid heat exchanger/cooler down between radiator and oil pan like any other LMTV, so you shouldn’t be overheating just the trans if you are not working it hard enough to need an aux cooler. If I recall correctly from a discussion with a gentleman who was relocating the aux...

Most everything except the lighting is 24V, but the main ignition switch uses 12V to energize the control power relay (K02) that powers all the 24V circuits… Here is an abbreviated start circuit diagram I condensed from the A0 tech manual. You might need this When it comes time to start it:)...

If you are missing the other smaller device in the above pic that Ohiobenz posted, that is an instrunment shunt, used to measure current flow. It is placed in the main ground line between battery and starter and can measure crank current and total alternator output back into the batteries. The...

Yea, that is the polarity protection box. It is just a set of diodes that prevents batteries that are connected backwards from doing damage in the cab. To get you off the lot, it can be bypassed, just don’t hook up your batteries backwards. In the attached pic, connect the wires circled in...