My next "whats this?" thread...windshield sprayer hose (1 Viewer)

[calsbeek]

The windshield sprayer hose on my BJ74 was disconnected when I bought it. The line that I think it should be plugged into (indicated by a yellow arrow) is instead connected to this small doodad (circled in yellow) behind the master cylinder.

so:

1. What is that doodad? and
2. If I connect the sprayer hose to that line, what should go onto the nipple end of the doodad instead of the hose that is currently on it?

 

[BJ74PE]

Hey there Cal

1. That couple of cylinder-shaped doodads are VSVs (vacuum switching valve) that activate the 4WD in the transfer case (via the 4WD button in the dashboard). Each of these should get 2 vacuum lines as well as a couple of wires. It seems that the one on top is broken and someone has mistakenly attached the sprayer hose to it. Part number is 85440-60160 (seems to still be available).

2. There must go a similar black cylinder like the one below still attached to the vsv.

Hope it helps; you might still be able to switch to 4H by swapping the vacuum lines. Although, you will have to swap them again to go back to 2H.

Hope it helps.

Daniel.

 

[calsbeek]

Hey there Cal

1. That couple of cylinder-shaped doodads are VSVs (vacuum switching valve) that activate the 4WD in the transfer case (via the 4WD button in the dashboard). Each of these should get 2 vacuum lines as well as a couple of wires. It seems that the one on top is broken and someone has mistakenly attached the sprayer hose to it. Part number is 85440-60160 (seems to still be available).

2. There must go a similar black cylinder like the one below still attached to the vsv.

Hope it helps; you might still be able to switch to 4H by swapping the vacuum lines. Although, you will have to swap them again to go back to 2H.

Hope it helps.

Daniel.

That is super helpful thank Daniel,

although it doesn't explain why my 4WD seems to work ok...?

 

[calsbeek]

Ok I'm starting to question everything, including whether my 4X4 is actually working. The other solenoid has this black plastic cylinder thing attached to it. Is that all I need for the other solenoid? Or is this piece incorrectly installed as well?

 

[BJ74PE]

That is super helpful thank Daniel,

although it doesn't explain why my 4WD seems to work ok...?

Well, the VSV's won't interfere with the 4WD if you use the transfer lever (L4).

Still, I really don't know how the internals of these solenoids work but surely someone else in the forum might be able to further explain it and why the H4 button still works.

Glad I could help.

Daniel.

 

[BJ74PE]

Ok I'm starting to question everything, including whether my 4X4 is actually working. The other solenoid has this black plastic cylinder thing attached to it. Is that all I need for the other solenoid? Or is this piece incorrectly installed as well?

View attachment 1490546

I'm not sure if that cylinder should come off that easily; I thought it was attached/glued to the solenoid. Anyhow; another one should be installed in the other solenoid. I'll take a pic of my rig's and upload it.

 

[calsbeek]

Ok, quick update here. I just went out and put my finger over each solenoid (where that black cylinder thing was on bottom one (see purple finger pic above)). I have vacuum pressure on both solenoids when I push the H4 button in and out....

So I'm thinking I just need to cap the top one?

 

[BJ74PE]

Pic attached.

Might just be a fancy cap or work as a relief/check valve for vacuum in the system. Can't be sure.

There are more experienced guys with this topics in the forum that will certainly contribute.

PD. Did you try having the 4WD engaged by capping the wholes with something else other than the black cylinder cap?

 

[hotgemini]

Just correcting something from earlier in the thread, those two solenoids are the only thing which engages/disengages 4wd. They are either switched by the H4 button on the dash or moving the transfer lever to the Low range position. Either way it still engages/disengages by those solenoids.

One of the solenoids died in my BJ74, so until I got around to fitting a fully manual shift transfer case, I used to just directly connect the appropriate output line to the vacuum supply line.

You should be able to work out pretty easily which of the vacuum lines is the supply, then from that work out which port on the solenoids is the output. In high range with the H4 button NOT depressed, vacuum should only exist at the outlet of one solenoid. When you either put the transfer lever in low AND/OR depress the H4 button, vacuum should exist at the outlet of the other solenoid, but not the original one.

The caps are just vents, the solenoids connect the output port to the vented cap when they're de-energised which releases the vacuum in the output line and the actuator diaphragm.

 

[calsbeek]

Whats PD?

No I didn't cap either one. I removed that black cylinder (which I'm thinking might just be an air intake filter of some kind to prevent crap from getting in the lines?) and just put my finger over the tubes and then pressed the H4 button to feel the vacuum.

 

[calsbeek]

The caps are just vents, the solenoids connect the output port to the vented cap when they're de-energised which releases the vacuum in the output line and the actuator diaphragm.

Ok cool, so my suspicion was accurate. With vacuum pressure on both solenoids it looks like all I need is a cap for the naked port and I'm good to go.

Correct me if I'm missing anything, but thank you everyone in the meantime.

 

[hotgemini]

I'd strongly suggest making sure they actually switch. Just getting vacuum to the solenoids isn't enough.

Much easier to diagnose and fix it in the driveway at home than in the dark/rain on the side of a track somewhere.

 

[calsbeek]

I'd strongly suggest making sure they actually switch. Just getting vacuum to the solenoids isn't enough.

Much easier to diagnose and fix it in the driveway at home than in the dark/rain on the side of a track somewhere.

Whats the best way to do that? Maybe put the rear wheels on jack stands and drive off with the front wheels?

 

[hotgemini]

The green H4 light on the dash should be a pretty reliable indicator, it is a separate switch which detects the 4wd selector rod position.

Alternatively, with the hubs unlocked, climb underneath in 2wd and make sure you can spin the front driveshaft. Then put it in 4wd and make sure you can't (hubs unlocked still)

 

[calsbeek]

Sweet, i just did the driveshaft test and it spins when the green button is off, but doesn't when the green button is on.
I'm good to go.