Plumbing schematic LT95 CDL vacuum controls

[Lotz-A-Landies]

Does anyone have a simple schematic for the vacuum hoses and pneumatic switch in a Perentie?

Particularly:

• the switch port number for the vacuum supply
  the switch port numbers for the engage and disengage functions
  hose colours for each function
  does the switch vent to atmosphere (+which port number)

[Blknight.aus]

the valve is a 5 port 2 position valve yes the valve ports the not selected side to atmosphere, thats why you hear a sucking noise behind the dash from the valve if the diaphragm fails.

the top 3 are vent, vac supply, vent

the bottom 2 are engage and disengage.

From memory Red goes to the outboard position for the actuators on the box and is the disengage function
White goes to the inboard postiion and is the engage postion.

where that goes on your particular valve depends on the orientation of the ports and spool on the valve you get

OEM part number BYG2049

you can use a 4 port 2 postion valve in the same place its basically the same but the exhaust ports are joined internally to a single outlet.

the electrical version
https://www.ebay.com.au/itm/15478997...J47PBe5tqCyK8W
the manual version
https://www.ebay.com.au/itm/22704971...Bk9SR8bH-LnKZg

as with all things, the generi part numbers for a local pnuematics suppliers are the part numbers in the listing

[p38arover]

Does this help or do you already have it?

BYG2049.JPG

The RPS says that tube 14 is red, 15 is white, 17 is black.

[Lotz-A-Landies]

This is the switch.

Thanks Dave and Ron.

As to Ron's question, no I don't have the manuals at this location, and don't want to take my Perentie apart because its doing an RSL event on Saturday, ( this switch not for that vehicle).

[Lotz-A-Landies]

the valve is a 5 port 2 position valve yes the valve ports the not selected side to atmosphere, thats why you hear a sucking noise behind the dash from the valve if the diaphragm fails.

the top 3 are vent, vac supply, vent <snip> ...

....<snip>the electrical version
https://www.ebay.com.au/itm/15478997...J47PBe5tqCyK8W
the manual version
<snip> ...

...<snip>

This gives me an alternative option.

The install is for the intermediate axle on my Defender RB-6x6 Ikea (because it came to me flat packed).

I could use the electrical solenoid connected to an instantaneous switch on the CDL cable for the LT230, this would engage the lock on the middle axle at the same time as the CDL is engaged.

[Blknight.aus]

This is the switch.

Thanks Dave and Ron.

As to Ron's question, no I don't have the manuals at this location, and don't want to take my Perentie apart because its doing an RSL event on Saturday, ( this switch not for that vehicle).

on that valve...

5 and 3 are vents 1 is supply

2 goes to open diff
4 goes to locked diff

[Lotz-A-Landies]

Just a Q on a similar issue.

My Defender 6x6 now has an Isuzu 4BD1-T and an Isuzu MSA5Sx2 gearbox close coupled to an LT230.

The overdrive on the back of the MSA gearbox has had it's linkage modified to use an air solenoid (linear motor) instead of a shift lever or cable. The gearstick has a Scania truck knob with electrical switch for the overdrive.

Can I use the same electric solenoid (air switch) recommended above by Dave to control the linear motor?

air solenoid red.jpg

I assume the plumbing on the air switch would only use 3 ports because I wouldn't want the air supply to constantly vent to atmosphere. Or am I misunderstanding?

My other thought would to plug one of port 3 or 5 instead of venting to atmosphere.

[Blknight.aus]

Just a Q on a similar issue.

My Defender 6x6 now has an Isuzu 4BD1-T and an Isuzu MSA5Sx2 gearbox close coupled to an LT230.

The overdrive on the back of the MSA gearbox has had it's linkage modified to use an air solenoid (linear motor) instead of a shift lever or cable. The gearstick has a Scania truck knob with electrical switch for the overdrive.

Can I use the same electric solenoid (air switch) recommended above by Dave to control the linear motor?

air solenoid red.jpg

I assume the plumbing on the air switch would only use 3 ports because I wouldn't want the air supply to constantly vent to atmosphere. Or am I misunderstanding?

My other thought would to plug one of port 3 or 5 instead of venting to atmosphere.

I think you're misunderstanding.

what you've got pictured looks like a 2 way actuator. you would hook it up to the 2 port side of a 5 way pnuematic valve (mechanical or electrical) and the supply of pressurised air or vacc supply to the middle of the 3 ports.

When you have the switch in the normal position supply connects to one of the (the first) actuation ports. The other (second) actuation port is connected to one of the 2 vents. When you change the position over the supply is connected to the other (second) actuation port and the other vent is connected to the original (the first) actuation port.. Its done this way as it makes forming the spool and body for the valve very easy to manufacture. A 4 port valve functions similarly but uses a differetn spool configuration or has a 5 port setup but the vacuum ports are linked internally.

yes, you can use the same style of electrical switch to operate that actuator for the overdrive. If you're using the lt230 with the low range switch and or the Diff lock indicator you could also tie that to the overdrive switch so you cant select overdrive with low range or difflock engaged. It might take an extra realy depending on if you have, NO, NC or a combination of both switches on the Tcase.

IF it helps, you can buy the hosing in multiple colours and sometimes you can get it in "service lengths" as a multi coloured multipack. Once youve got all your valving and worked out what you want to actuate on vacuum or air by means of electrical or mechanical switching I can diagram it up for you and chuck an arbitrary colour code on it.

also Depending on what that max pressure sticker is ment to say, you may need a pressure regulator if you're going to operate on pressure.

[Lotz-A-Landies]

I think you're misunderstanding.

what you've got pictured looks like a 2 way actuator. you would hook it up to the 2 port side of a 5 way pnuematic valve (mechanical or electrical) and the supply of pressurised air or vacc supply to the middle of the 3 ports.

When you have the switch in the normal position supply connects to one of the (the first) actuation ports. The other (second) actuation port is connected to one of the 2 vents. When you change the position over the supply is connected to the other (second) actuation port and the other vent is connected to the original (the first) actuation port.. Its done this way as it makes forming the spool and body for the valve very easy to manufacture. A 4 port valve functions similarly but uses a differetn spool configuration or has a 5 port setup but the vacuum ports are linked internally.

...... <snip>.

I still think I'm misunderstanding.

What I have purchased is two of the electropneumatic switches you recommended. One will be used with vacuum to operate the middle axle diff lock using an instantaneous switch on the CDL as discussed at the beginning of this thread.

The second electropneumatic switch will be used with positive pressure (generated via a single compressor and pressure cutout from the Accuair suspension kit) to operate the overdrive on the main gearbox.:- The switch on the gearstick will close commanding the electropneumatic switch to supply pressure to the actuator (1-4) this should extend the actuator shaft to engage overdrive. This is where I'm unclear: the other port on the actuator is connected to Port 2 on the valve. Isn't this open to exhaust? When the gearstick switch is opened pressure from 1 is lost and the air should be vented via 2-3. What is happening to the pressure still at 1: is this venting through 5?

[Blknight.aus]

I still think I'm misunderstanding.

What I have purchased is two of the electropneumatic switches you recommended. One will be used with vacuum to operate the middle axle diff lock using an instantaneous switch on the CDL as discussed at the beginning of this thread.

The second electropneumatic switch will be used with positive pressure (generated via a single compressor and pressure cutout from the Accuair suspension kit) to operate the overdrive on the main gearbox.:- The switch on the gearstick will close commanding the electropneumatic switch to supply pressure to the actuator (1-4) this should extend the actuator shaft to engage overdrive. This is where I'm unclear: the other port on the actuator is connected to Port 2 on the valve. Isn't this open to exhaust? When the gearstick switch is opened pressure from 1 is lost and the air should be vented via 2-3. What is happening to the pressure still at 1: is this venting through 5?

yep.

so lets lable our ports...

port 1 is supply pressure
port 3 is vent 3
port 5 is vent 5.
ports 2 and 4 are just port 2 and 4.

in postition one (which for this example will be with the electrics unpowered) and If my ascii art works out heres whats happening inside the body with the spool moved from one position to the next


vent 3 is closed
port 1 supplys pressure to port 2 and
port 4 is vented through vent 5

Vent 3 supply port vent 2
...V...........V............V
.....|---------|............
......^.............^
... port 2... port 4

in position two (solenoid powered

port 2 is vented through vent3
port 1 supplies presure to port 4
vent 5 is closed.


Vent 3 supply port vent 2
...V...........V............V
............|---------|.....
......^.............^
... port 2... port 4


The spool in this example is moved by a spring to the first position and then pulled into the second position by an electric solenoide setup.

Depending on how you like your defaults you should configure the system so that on electrical loss the default position is your safest/most reliable/default configuration. there is an alternative configuration for the electrical part of the solenoid which is an over center configuration which means it will only change position on the iinitial application of power. you press a momentary switch and it will flick over and stay there till you give it another pulse of power. Some are electronic but the older style are more like a detent ball setup with some clever wiring of the pull and hold windings of the electromagnet.