Replacing the A4LD Vacuum Modulator
 

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If your Modulator has failed (like mine) then when you take the vacuum line off transmission fluid will drip out (flow out)

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Loosen the bolt (its 10MM) and take the bracket out

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Old modulator on the right, new one of the left

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This is the thin metal pin inside the modulator... DO NOT LOOSE THIS!!!! transfer over to the new modulator

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Pictures of the only modulator

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Picture of the new modulator

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Bracket used to hold the modulator in place

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Space were the modulator goes

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New modulator in place with vacuum line hooked up

not so hard to do when the car is jacked up;)

RE: Replacing the A4LD Vacuum Modulator
 

What are the symptoms of this failing? nice pics by the way!

RE: Replacing the A4LD Vacuum Modulator
 

Later shifts, transmission fluid in the lines, and a wired burning smell (also bad shifts)

RE: Replacing the A4LD Vacuum Modulator
 

cool, just asking for later viewers of this thread. It should be put in the tech articles.

RE: Replacing the A4LD Vacuum Modulator
 

Already there;)

Don't have the contributor badge for nothing [8D];)

RE: Replacing the A4LD Vacuum Modulator
 

how much did it cost you for the new one? And where did you buy it at?

RE: Replacing the A4LD Vacuum Modulator
 

$15, and I got mine from auto parts plus. Any store should carrie it;)

RE: Replacing the A4LD Vacuum Modulator
 

checked mine today and it was leaking badly. So i replaced it and figured i would change the filter and fluid in the tranny also. Well come to find out my trans is out of a 90 mustang even though my mustang is a 91. Drove nearly clear across town to the parts store that had the 91 filter to find out it didnt fit F*** me. Should have double checked.

Sleeper does your new one have an adjustment screw on it?

RE: Replacing the A4LD Vacuum Modulator
 

Yes it does, but thats because its the turbo one (highly recomend it since you can change your shift points with it;))

RE: Replacing the A4LD Vacuum Modulator
 

good thats the one i got:D glad to hear i can adjust my shift points now!!!!

RE: Replacing the A4LD Vacuum Modulator
 

I used to have a 93 mustang lx, and now I have one again. The old one would drop to idle when you released the accelerator, but this one doesn't.

Is that another symptom of a bad regulator, or is that a bigger problem?

RE: Replacing the A4LD Vacuum Modulator
 

The RPMS should slowly go down with the speed, acts like a brake sorta.

The only way to know if its blown is to take the vacuum line off it and see if transmission fluid comes streeming out

RE: Replacing the A4LD Vacuum Modulator
 

Nice post bro ;)

I just replaced mine cause a bunch of fluid poured out, but the car still has trouble going into gear for some reason, if i rev it up to 3k it wil usually pop into gear and go but will go back out of gear if i take a slow turn or at the lower gears. i hope this is not a failing transmission....

i think ill also replace the 1/4" rubber hose, also, ifthere was fluid left in there when i put the new one in could that cause it to have same problems? also when i pressed on the new modulator to make sure i put it in right, after i drove to get smokes and back, a bit of tranny fluid came out of the hole..

ill replacethe hose since maybe the old one isnot securing tightly im guessing it could lose suction and cause same problem.. otherwise idk im at a loss..

Hey, just wanted to point out i resolved my issues. Had to do a couple more steps on my own heres what I found.

The small black hose that was initially unplugged and checked for fluid was replaced since it wasnt as tight as I expected it to be...

All vaccuum lines were unplugged and drained one at a time since I had alot of tranny fluid in them I guess thats why the problem was not resolved... A couple of the lines had an inch cut off the end and then plugged back in to make a tighter fit... just make sure you can afford to clip the end off before doing so, evin still new ones are only about a buck or two a foot....

I checked fluid level and tranny fluid was quite low since so much escaped into the lines...
I added a whole liter slowely and check level throughout...

everything is perfect, thanks for this post you rock...

GOOD DAY

would that module allow my car smoke it seem that when my tranny started to act up it started to blow smoke it would qiet and the start up after the trans would act up
check fliuds and i have no water in oil ?

I took out my modulator and the metal pin was not there. Does anyone know where I can get a new one so my truck will shift properly?

found one now just got to adjust it...