94 Ranger XL -Instructions on how to replace a vacuum modulator.

[OneofMany]

Wowsers! fixed!
Took me most of the day when including changing the oil, fixing vacuum lines, lubing the seats and vacuuming the carpet. I diagnosed correctly- at on back
The modulator sucked trans oil into the engine making it run crappy...I hated taking the seats and carpet loose, almost cut the 3 bolts on the front and 3 on the rear of the cats off to get at the modulator....i think thats how its supposed to be done anyway. going at it from the bottom lets you inspect and/or replace the solenoids while ur in there. But in an ageing vehice you end up cutting bolts and finding replacements. I think another short-cut is to simply cut around the access hole on the hump inside the car instead of picking up the carpet. Just cut it out and glue it back later...
Either way- engine runs smooth without even cleaning the plugs. Trans shifts great and no more smoke cloud.

 

[micahp83]

i now have no reverse or overdrive. any ideas

 

[BrooklynBay]

Does it start in park & neutral? Do you see the reverse lights turn on when you shift into reverse? If not, then the Z link might be bent or broken or the shift cable might have disconnected.

 

[project crew]

Need help with the vacuum modulator - still smoking...

Just followed all the steps for R&R of new vac modulator. Started the 94 ranger up and she's still smoking. Quite a bit, more than usual. Going to do a quick oil change, see if that helps get rid of all the ATF in there. Looking for help! Thanks.

 

[BrooklynBay]

Seafoam will smoke when it's in the system.

 

[project crew]

Thanks BB

Problem solved. Seems that the new, off brand vac mod was faulty. Had ATF in both sides of the new part after install and running the truck. Went to a different store and got the Fram vac mod, installed it, and all is well. The Fram part says its adjusted to OE specs. The truck is running great, no more smoke. Thanks for this thread.

 

[BrooklynBay]

Thanks for the update! Do you know which brand the defective modulator was?

 

[project crew]

Didn't see any brand name on the box. White box, red & blue design. Made in Mexico sticker on the lid of the box, brass colored, adjustable vac mod, $12.99. From now on, I'd go with the Fram modulator ($20) from the start just to get the OE adjustment. (The Ford dealer wanted $140 for their vacuum modulator...)

 

[bestes]

Success!

Just wanted to say, I have a 1992 Ford XLT Ranger. I have had the same problem with the transmission leak and fluid in the vacuum line. I was hesitant to replace the modulator on my own, until I found this post.

I bought my replacement from Rockauto.com for about $17. It was a ATP brand. (made in usa).

I followed your instructions (went in through the hump access panel) and everything went smooth and easy. The old truck is running great.

Thanks for the help, I wouldnt have attempted it without this thread.

 

[smegun]

got to the modulator marv

anyway main question yea i see the little bugger in some kind of thin metal frame with the heat shield from the cat in the way too ....any more description on pulling it out might help ......




i was looking for a possible vacuum leak but i dont think its from my modulator the hose appears ok but if i get back twards my drivers side rear wheel i hear what sounds like 2nd floor water running in small copper pipe ...what can it be ? only when truck is running ....sshshshshshsshhshshhshhhhhhshshshhhshsshshshshshshshshshshshshshshhsshshshhsshshsssssssssssshshshshshshshshshshshshshshshs ???????

...there is a few bad clips it sits squarely in the center of the hump forward of the center consul unfortunately i think the consul gets in the way of peeling the carpet back and easy access when i put it back im going to look how far the consul sits to see if i can velcro a patch carpet for easy access but for now the clips are too frozen to deal with you have to remove the consul to get to the trap door need the leverage for grinder ...:/ going to need new clips or artist impression putting panal back

 

[RollsRoyce]

I have a 1994 Ford Ranger XLT 6cyl 4.0l 4WD with an A4LD auto transmission that has trouble shifting from 1st to 2nd gear when it is cold. Once it warms up it seems to shift ok. No smoking issues. After reading this thread I decided to buy an aftermarket adjustable modulator and replace the old one. I took out the exhaust and replaced the old modulator and put the new one in and it immediately starting blowing out volumes, I mean volumes of white smoke that smelt like oil. I reread the thread and then remembered I did not see the modulator pin during the replacement. I pulled the replacement modulator out and saw there was no pin in it. I felt around the area and to my surprise I found the pin laying on the transmission. I put the pin back in with the replacement modulator and it was still pouring out white smoke....Thinking the replacement modulator was bad I went into Amazon and ordered the OEM Motorcraft modulator for $50. When it arrived I got back under the truck and removed the hose from the aftermarket modulator and noticed about a couple of ounces of oil drain out of the line. I then replaced the aftermarket modulator with the new oem modulator carefully making sure the pin was installed with it. I then started the engine and it is blowing a lot of white smoke again. I have started it multiple times and run it for about 10 minutes each time at which time I have to turn the car off as the smoke is so bad I worry about my neighbors. I did notice when backing it onto the street that The transmission was slipping a lot. I checked the fluid level which was low and put 600 mls in it before it got to normal fluid range (I did this while the engine was running). I still can't get reverse as it slips like crazy and it's still billowing smoke. Transmission is not slipping in drive. Need help please, it's my sons first car, we have done lots of work to the truck, it's a really nice truck and would be perfect if we could just get this transmission working. On a side note, we purchased the truck from the neighbor who let it sit in the driveway for five years without running, he's the original owner and it only has 100 000 miles on it. I hope this means the transmission should be ok. Thanks for any help from the forum.

 

[BrooklynBay]

Did you clean the vacuum line with Seafoam? This will cause white smoke to blow out of the exhaust until it is completely burned up.

 

[RollsRoyce]

Did you clean the vacuum line with Seafoam? This will cause white smoke to blow out of the exhaust until it is completely burned up.

Thanks for responding BrooklynBay. No i did not use the foam. Do you recommend using it? I have a can of it here at home. Do you just put it in the brake booster like usual?
Do you think it's just residual oil in the line only that's causing the problem?

 

[BrooklynBay]

Disconnect the vacuum line from the modulator, and put a little Seafoam into it with the engine running. You will get a lot of white smoke until everything goes out of the system. This will remove any residual transmission fluid which is left in the lines.