dimbailh

Hi, can someone tell me what part this is..it has vacuum lines running in/out of it? 1st gen 89 V6 Thanks.

RobD

Are they on your passenger side fender? If so, they look like the vacuum switching valves for your 4WD. Does your truck have the Automatic Disconnecting Differential (ADD)?

dimbailh

Yes they are on the passenger fender. I have no idea if i have the ADD..I would like to know though..how can I tell?

dimbailh

I did a quick google and I think since I have automatic hubs I don't have the add

RobD

http://www.off-road.com/trucks4x4/ar....jsp?id=399612

yodathespian87

I believe it is the ADD vaccum switch. Seeing as you have automatic hubs that would mean you do have ADD. Stands for Automatic Disconnecting Differential.

RobD

If he has automatic hubs, then he won't have ADD. With auto hubs, he has to be stopped to shift into 4WD and back up to release them when he's done. If he has ADD, he can shift on the fly because the front hubs are always "locked".

yodathespian87

Hmm. Then I must have learned that part wrong then. Or is that still a VSV switch? I thought it went down to the front diff. ???

RobD

No, I think you're right. It looks like the VSV to me, too.

But if you click that link I posted, it details how the ADD system works. The hubs on an ADD truck have flanges that bolt directly to the front axles. They don't unlock at all.

Check the link. It does a way better job explaining how it works than I ever could.

JonnyBoy

Those are definitely vsv's for 4wd.
Toyota part number 85440-35010. That part number is for the assembly, and really expensive from the dealership, so I'd suggest trying wrecking yards. Best bet might be to pm Deathcougar.

bugs1961

If you take a look at the FSM you'll see that on the '89 3.0 there are 3 (4 if you have air conditioning) VSVs on the fender. See this thread for more information on where the vacuum lines go and what the valves do: https://www.yotatech.com/forums/f116.../#post51141054

The VSV valves are:

rear (blue connector), : VSV for PAIR and has hose #1 attaching to the fender side of the VSV, and hose #4 attaching to the engine side of the VSV.

middle (brown connector): VSV for the FPU system and controls the fuel pressure regulator. Hose #2 attaches to the fender side and hose #5 attaches to the engine side. Hose #2 has a T fitting that has a hose going to the forward most VSV that controls the AC idle up.

middle (green connector): VSV for the EGR system and has hose #3 attaching to the fender side and hose #6 attaching to the engine side.

forward VSV (gray connector): This controls the idle up for the air conditioning and has a short vacuum hose that goes from the diaphragm to the fender side of the VSV, and a vacuum hose that goes from the engine side of the VSV to the T fitting in hose #2. There are two larger air hoses coming out of this VSV to provide extra air with the A/C on.

There are 2 additional VSVs for 4wd on the passenger side wall of the fender on an '89 3.0 truck only if you have ADD.

I hope this is a little clearer than mud. Good luck,
Bugs