Vacuum problems

[werewolf]

Got this 1999 3.0 Ranger 4x4 manual five speed. I bought it a while back to to have a back ride. Had my son go check it out for me said everything works find. got my brace unlocked today broken leg. And at a idle everything works but you drive it A/C stops blowing.You back off the throttle it blows again. Old school says a vacuum leak. I've looked in the tech, didn't see much on vacuum. Did see a part vacuum hubs. But are the A/C controls run with vacuum or elct. Is there a most common place to look or just start digging. And is the hubs really work off vacuum. I'm sure i over looked it in the tech com. Hope i'm putting this in the forum

 

[RonD]

In engine bay, firewall, passenger side, you will see 2 vacuum lines coming out, usually a grey one and a black one, these are the hard vacuum line so may look like wires.

The grey goes to Heater hose valve

The black one is the vacuum for the vents, this is the one you want to follow
If often gets melted near exhaust or breaks because it is dryed out, it can be repaired using flexible vacuum hose of correct inside diameter for a snug fit, remember it is Vacuum so no clamps are needed, it will hold itself in place.

Other issue could be the vacuum reservoir, thats where the black line runs to, usually at the very front of the engine bay passenger side, down low, under the frame, looks like a black ball

These can crack and so can't hold vacuum, so when you accelerate vacuum drops, and vents change positions.
Defrost is the default, no vacuum, position of the vents.

System looks like this

Intake manifold(vacuum source)---------Check valve/reservoir------------firewall------climate control

In 1998 to 2000 there will also be a "T" in the line going to the firewall, thats for the Pulse Vacuum Hubs

 

[werewolf]

Thanks Mr. Ron

Thanks Sir, give me somewhere to start looking. I seen the vacuum line from the intake, looked like it go's down under the A/C box. And can see a gray one coming out from under the box to the heater hose. It looked like a black one going under the air filter box. This 3.0 seems to run a little bit better. I cut out the muffler welded some flanges and put in a straight exhaust pipe. put some on the muffler. It comes inspection time, unbolt the pipe four bolts two on each in and bolt up the muffler back. Left the cats didn't miss with them. don't won't check engine light or fault codes.

 

[cbxer55]

On the no muffler, been doing that for years. Had the muffler removed, welded a bent Y to the converter, and attached two polished steel long tips to the Y, sticking out in front of the passenger wheel. Only downside is I can't keep that wheel or the lug nuts on it clean. I have to polish them four times as often as I do the other three. Thinking about just making them black and calling it a day.

Sounds mean though. Combined with a big 3 inch stainless intake tube and a stainless steel mesh filter, it growls. I've had several people ask me what's under the hood. When I tell them a 3.0 V-6, they're like "No way dude". A friends dad told me it sounded like a V-8. LOL

 

[werewolf]

well dug out some of my old automotive tools. Vacuum gauge and hand vacuum pump good old Matco tools. pulled out the enter plastic finder, to get to all the hoses vac can way up front passenger side. And there is some kind of a elec. Vacuum switch above that a black vacuum line out of it going to both front hubs. I have grate vacuum ever where till i plug back into the,i'm going to call it fwd switch. Once i turned on 4high with the gauge on the out vacuum gauge came up to the green and then it dropped again to almost 0. What is this switch or elec.valve called so i can try to find a new one. Is it one of those dealer only parts.

 

[RonD]

Have a read here: http://www.therangerstation.com/tech_library/troubleshoot-fix_pvh_hubs.shtml

Also here, if you want to eliminate these PVH hubs: http://www.therangerstation.com/tech_library/AVM_hub_swap.shtml