First Drive Today

[hubcityford]

I think there are two vacuum motors back that. Best case one of the hoses is off. Worst case is that one of the motors has a split diaphragm. Anyway, take a look at this page from the 1981 EVTM: http://www.garysgaragemahal.com/heating-ventilation--air-conditioning.html.

And with a light go up under the dash and check the hoses. Also, you might remove the glove compartment liner as that gives you a view into that area that is hard to get otherwise.

Everything looks to be connected. I pinpointed the noise coming from the rotating portion of the control arm that directs to vent, normal, max, etc. I took photo with a bolt pointing to the hole that noise is coming from. My hand is on the back of ash tray. There is a spring between leaking piece and ash tray. I assume all the small tubes coming in on back tell the AC system what vents to open and close ?

Is there a way to remove vacuum from AC temporarily so truck will run fine until I figure out the AC leak?

Jeremy

[hubcityford]

Everything looks to be connected. I pinpointed the noise coming from the rotating portion of the control arm that directs to vent, normal, max, etc. I took photo with a bolt pointing to the hole that noise is coming from. My hand is on the back of ash tray. There is a spring between leaking piece and ash tray. I assume all the small tubes coming in on back tell the AC system what vents to open and close ?

Is there a way to remove vacuum from AC temporarily so truck will run fine until I figure out the AC leak?

Jeremy

[Gary Lewis]

Yes, you can easily pull the vacuum from the HVAC system. In the pic below you can see the hose coming from the plastic manifold on the firewall to the tee/check valve. If you pull the hose off the tee/check valve and plug it that will do it. But, be careful as the little plastic hoses are usually brittle.

[FuzzFace2]

Yes, you can easily pull the vacuum from the HVAC system. In the pic below you can see the hose coming from the plastic manifold on the firewall to the tee/check valve. If you pull the hose off the tee/check valve and plug it that will do it. But, be careful as the little plastic hoses are usually brittle.

http://forum.garysgaragemahal.com/file/n55663/rustys-hvac-plumbing_orig.jpg

Don't over look that "juice" can that is part of the HVAC system as vacuum leak.

Mine had pin holes on the bottom & ends of the can.

My fix was to remove the can from the truck, remove the bracket from the can and use fiberglass rosin to coat the areas with the pin holes.

Once the rosin set up I painted it black put the bracket back on and back in the truck and it is good as new.

I do need to replace the check valve / Tee as it does not "check" and when giving it throttle you loose vacuum to hold the doors where they are set to.

I hope your HVAC control is not leaking as it sounds like as it can be a PITA to R&R.

Also they make 3 different ones based on years and are hard to come be new.

Good luck

Dave ----

 

[hubcityford]

Yes, you can easily pull the vacuum from the HVAC system. In the pic below you can see the hose coming from the plastic manifold on the firewall to the tee/check valve. If you pull the hose off the tee/check valve and plug it that will do it. But, be careful as the little plastic hoses are usually brittle.

http://forum.garysgaragemahal.com/file/n55663/rustys-hvac-plumbing_orig.jpg

Don't over look that "juice" can that is part of the HVAC system as vacuum leak.

Mine had pin holes on the bottom & ends of the can.

My fix was to remove the can from the truck, remove the bracket from the can and use fiberglass rosin to coat the areas with the pin holes.

Once the rosin set up I painted it black put the bracket back on and back in the truck and it is good as new.

I do need to replace the check valve / Tee as it does not "check" and when giving it throttle you loose vacuum to hold the doors where they are set to.

I hope your HVAC control is not leaking as it sounds like as it can be a PITA to R&R.

Also they make 3 different ones based on years and are hard to come be new.

Good luck

Dave ----

Well it seems to be a little better and no hissing from inside cab AC. I think there is more vacuum issues than the AC. Probably going to take to my “go to” mechanic so he can give it a once over. I’m going to let him look over brake system. So far that is the scariest thing, brakes seem fine but then they just go away and I’m to the floor with pedal. I’m only doing small drives around neighborhood and not getting over 15 mph. Figure I can down shift and hit emergency brake and bail out before a firey crash.

JV

[Gary Lewis]

Well it seems to be a little better and no hissing from inside cab AC. I think there is more vacuum issues than the AC. Probably going to take to my “go to” mechanic so he can give it a once over. I’m going to let him look over brake system. So far that is the scariest thing, brakes seem fine but then they just go away and I’m to the floor with pedal. I’m only doing small drives around neighborhood and not getting over 15 mph. Figure I can down shift and hit emergency brake and bail out before a firey crash.

JV

I think you are saying you plugged the vacuum line and the hissing in the cab stopped and it seems to run a bit better. Right? But that there may well be other vacuum issues, which is very possible given the age of the vacuum lines on these truck.

However, having brakes is paramount, so having someone look at that is a good idea. He may find that the master cylinder is dry and, if so, the brakes will need to be bled.

[hubcityford]

I think you are saying you plugged the vacuum line and the hissing in the cab stopped and it seems to run a bit better. Right? But that there may well be other vacuum issues, which is very possible given the age of the vacuum lines on these truck.

However, having brakes is paramount, so having someone look at that is a good idea. He may find that the master cylinder is dry and, if so, the brakes will need to be bled.

You are correct with your summary. Still more to come with vacuum issue.

On to next thing...I hopefully will have all my new belts tomorrow. Is there anything I need to know when installing new belts? Just get tight or is there any trick to it?

Thanks

Jeremy

[Gary Lewis]

You are correct with your summary. Still more to come with vacuum issue.

On to next thing...I hopefully will have all my new belts tomorrow. Is there anything I need to know when installing new belts? Just get tight or is there any trick to it?

Thanks

Jeremy

Better a bit loose than too tight. Too tight hurts the bearings. But new belts will stretch a bit, so check them after you've driven an hour or so.

I like to see about 1/2" of movement in the middle of the belt when I push with my finger.

[hubcityford]

Congrat's! Getting to drive it is such a good feeling.

You say it idles well in neutral, but not in gear. However, then it runs ok once you accelerate? That sounds like an incorrect air/fuel mix at idle. Probably lean, which could be from a vacuum leak, and that could be due to a cracked hose, a hose that's come off, or a cap that's come off.

I'm sure it could use plugs and wires, but if it runs well other than idle I'd not rush to replace them as acceleration tests them far more than idle does. Instead look the vacuum hoses over very closely. VERY closely. They tend to get old and crack or even fall off, and that causes a lean air/fuel mix. The engine might run ok at idle with no load on it, but not with a load.

I took the truck in for brakes (and it hurt the pocketbook) and my mechanic mentioned that it was “running cold” and explained that that meant accelerator pump was not acting properly. Would this be another possible cause for sputtering instead of the vacuum you mentioned? Curious to know what kind of project accelerator pump replacement may be? Can a newbie like me accomplish?

Thanks

Jeremy

[Gary Lewis]

I took the truck in for brakes (and it hurt the pocketbook) and my mechanic mentioned that it was “running cold” and explained that that meant accelerator pump was not acting properly. Would this be another possible cause for sputtering instead of the vacuum you mentioned? Curious to know what kind of project accelerator pump replacement may be? Can a newbie like me accomplish?

Thanks

Jeremy

Yes, a bad accelerator pump might cause that.

As for if you can do it, let's first determine what carb you have. I believe it will be a Motorcraft 2150, but please go hear and verify that's what you have: Documentation/Fuel Systems/Carb's Chokes & EFI/Motorcraft 2150.

If that's the one you have then you should be able to rebuild it. That's a pretty simple carb, and the link to the instructions on the Ranger Station plus the instructions from the factory shop manual should be more than enough. But there are also lots of youtubes on it.

Having said that, if it is just the accelerator pump, which you can verify by removing the air cleaner and looking down the carb as you open the throttle, then you should be able to replace that w/o even removing the carb.