How To: Replace a vacuum modulator on an A4LD through the access panel (center hump).

[Exploring XLT]

What is the point of the adjustable one then?

 

[BrooklynBay]

It allows you to make fine tuning adjustments easily so that you don't have to insert a fine screwdriver. The non adjustable part is preset. You could calibrate it on a workbench if you have a vacuum pump with a gauge.

 

[Exploring XLT]

So I should purchase a non adjustable one stick it in and forget about it?

 

[BrooklynBay]

Yes, that's the easiest thing to do. Make sure that the bore, and the vacuum line are clean. Don't lose the pin.

 

[croatankid]

I'm concerned about losing that pin. As I pull the modulator out, will the pin stay inside the modulator? If not, how can I make the pin stay?

 

[transman304]

Most likely to come out with modulator but if lose it you can use a piece of metal coat hanger and cut a new one to a length of 1.450 +/- .060”
Make sure to put some lube on the o ring on the replacement before replacing in case.

 

[BrooklynBay]

Put a magnetic dish under the modulator while removing & installing.

 

[croatankid]

Thanks

 

[massacre]

Thanks for this I am getting the symptoms

 

[massacre]

Took heat shield off today in preparation. I have decided to try and attack this from the bottom with a mirror. Looks totally doable although my truck does not have the stock cat in the way.
Going to try and find a modulator today and some new vac hose as the stock hose is all oil swelled.

 

[croatankid]

Took heat shield off today in preparation. I have decided to try and attack this from the bottom with a mirror. Looks totally doable although my truck does not have the stock cat in the way.
Going to try and find a modulator today and some new vac hose as the stock hose is all oil swelled.

I have a new one that I don't need. It doesn't have the wheel adjustment but has a small screw for adjusting it. you can have it for postage. I paid around $35 for it. I bought it for my 1990 ford ranger, 4 liter. It's never been installed.

 

[massacre]

I have a new one that I don't need. It doesn't have the wheel adjustment but has a small screw for adjusting it. you can have it for postage. I paid around $35 for it. I bought it for my 1990 ford ranger, 4 liter. It's never been installed.

That’s very generous of you but I just got back from the parts store with the new one.
I may take you up on it in the future though if this one doesn’t work out.

Thanks for the generosity that is really nice of you!

 

[massacre]

Well this job wasn’t too bad from the bottom, was pretty awkward though. Pin fell out but was able to put into the new part and install it. New hose too.
I was contemplating doing this job from the top, but removing all the seats and installing new carpet at the same time.
But kinda glad I did it this way.
Had to use a small inspection mirror to find the nut to remove the heat shield and the nut that holds the bracket to keep the valve in place. It’s tight in there. Also have a small drain pain because atf will come out when you remove the valve, at least it did on mine.

But between the vacuum leak and burning the trans fluid in the engine, the truck runs much better now. Engine runs smoother and exhaust no longer smells terrible like it did before, especially in reverse. Trans is not as sluggish and shifts better, so glad I did this and it was cheap too.

Thanks to the OP for the pics and description, it totally helped me!

 

[extremeforce]

@cogs great! - I did the same job @ 93 Explorer 4x4 Eddie Bauer.
Hint: It's more comfortable to remove the driver seat too.