Are my vacuum lines correct(PICS). Also questions on MC bleeding.

[Stevoh]

Hey guys, nice site you have here! Lots of information. I did indeed search for my questions but could not find a precise answer. I got me a free Explorer 4WD which has some problems:

Vacuum: The truck would not idle correctly and would die. Sometimes when you would hold the revs to keep the engine from dying, and when you would eventually let it die there was a blow-off valve type of discharge sound. Accompanied with a nasty constant leak;found out that there were 3 un-capped or un-plugged vac lines/holes.

What is the hardline running atop of the intake mani? I have searched and come to think it is for the transmission. It was uncapped/unpugged. The 2nd was to the PVC but I capped it off, seems that there should only be one line coming off the PVC so I capped the smaller one. Why do they even come with the 2 port PVCs? The third was an uncorked hole in the vacuum tree on the rear of the intake mani. From diagrams I have seen this should either be capped or it goes to the tranny, so this is where I am stuck.

Are my lines good? The truck now holds a nice idle, but want to make sure lines are good.

The master cylinder is blown. Very low fluid in the reservior, obvious leaking around the brake booster(paint erossion). So my questions goes into brake bleeding. I have built a pressure bleeder for one of my cars(Ford Probe GT) and would like to use it for the Explorer as well. I was curious if any of you guys know of a cap that fits the reservior that is threaded all the way around? I had to use a different cap for the Probe as the fluid under pressure would seep out of the unthreaded sections on the stock cap. Anyone ever use a pressure bleeder for these trucks?

Otherwise, the truck is clean in terms of under body and suspension. The interior is another story: smells like **** as the previous owner was a smoker and used the truck as a garabge bin.Thanks guys. Look foward to your advice!

 

[walterd140]

Your vacuum tree off the engine looks like it's all there. Just check the back side to be sure.

I am curious about the bolt blocking the line in the last photo (sitting about 7 o'clock from the vacuum tree). My 94 has about 4 lines & 1 plugged. As long as they are all on there tight you will not have an issue. But just look around for a open port.

Another trick to check vacuum lines is to idle the x, then spray either wd-40 or ether on the lines. When the spray 'fixes' a hole the engine will purr better. Then you know that line is bad.

As far as master cylinders.... if you got a leak at the MC, be prepared to change the booster as well. Any brake fluid on the booster & it 's rubber bladder gets eaten like crazy. Better off switching the 2 at one time.

 

[Stevoh]

Walter, the bolt is plugging the 2nd port in the PVC valve vacuum body. From what I read, there should only be one(the main one going into the intake mani right next to the PVC).

I am most curious about if the hardline running atop the intake mani should be connected to the vacuum tree like I have it in the pics. :exp:

 

[boggs1227]

the hard vac on top of the intake is for the transmission modulator hook up and yes it does goto the vac tree.

for the interior take out the seats and take out the carpet ,hose down the carpet with "zep" commercial brand cleaner (home depot) with a garden sprayer ...let that soak in and then take the carpet to a car wash and pressure wash it clean .zep will take out almost everything in the carpet and make it smell great....it works .

 

[Stevoh]

the hard vac on top of the intake is for the transmission modulator hook up and yes it does goto the vac tree.

for the interior take out the seats and take out the carpet ,hose down the carpet with "zep" commercial brand cleaner (home depot) with a garden sprayer ...let that soak in and then take the carpet to a car wash and pressure wash it clean .zep will take out almost everything in the carpet and make it smell great....it works .

Thank you! Sweet so my vacuum should be good to go. And thanks for the advice on the carpet. I was worried I would have to get new carpet(more than likely at the pick n pull), but this sounds even better. I will be picking up some Zep soon.

 

[mikeinri]

Check the inside of those vac lines at the tree for tranny fluid. Most likely, you have a bad tranny vaccuum modulator (do a search here for that). When those go bad, tranny fluid gets sucked up into the vac tree, which will cause loss of tranny fluid (into the engine), which isn't detected (ie, no fluid goes on the ground). The warning sign usually is the engine stalling and puking off vac lines.

You should also make sure that the vac fittings are tight. Often with age, they get weak. Dealers should carry replacements (very cheap parts).

Hope this helps.

Mike

 

[boggs1227]

yeah mike has a point here...did you get the truck and see that the vac line for the modulator was plugged off ? chance's are that the diaphram in the modulator ruptured and was sending fluid into the upper intake thus the need to block it off .

either do a search for it or goto brooklynbay's helpfull tips ...he has alot of info that can help .

 

[Stevoh]

Cool thanks for the added insight. I do not know how or why the line was missing, it was completely missing. That is why I am curious if my lines are all good. I will probably just end up replacing the module. It seems you have to remove the carpet and get to in through the floor board. Good thing I will be removing the carpet anyways. Thanks again guys, I will be researching more on how to get this badboy in tip top shape.

 

[DeRocha]

Cool thanks for the added insight. I do not know how or why the line was missing, it was completely missing. That is why I am curious if my lines are all good. I will probably just end up replacing the module. It seems you have to remove the carpet and get to in through the floor board. Good thing I will be removing the carpet anyways. Thanks again guys, I will be researching more on how to get this badboy in tip top shape.

it is very common for the vacuum modulator on the transmission to rupture its diaphragm. As mentioned when this happens trans fluid gets slowly drawn into the intake and harmlessly burned. Unfortunately Trans fluid is destructive to the Rubber plugs and around the intake and will cause them to soften and fail.. If any plugs are oily & loose then trans fluid has got to them. I replaced the modulator through the access panel under the carpet and it was cake...

 

[abbott92]

What vacuum line is the one that runs along the back, on the firewall? Where does it lead to? I noticed when I bought my truck it idled a little high (at around 1100rpm) and when I looked at the tree today I found that there was a missing line. So then I ran my truck again and plugged the port at the tree where the missing line goes and my truck's rpm dropped right down to 900rpm and it ran awesome. I searched this site and this thread was the only one I could find that I thought could help me.

 

[DeRocha]

What vacuum line is the one that runs along the back, on the firewall? Where does it lead to?

It either leads to the Bi-metal sensor (top of the air box), or if its a hard line it goes to the transmission vacuum modulator. You should be able to follow the line to its source..

 

[abbott92]

That's my problem, the line that runs along the firewall is the one that is missing and I have no idea where it is supposed to come from. I'll check out the airbox and the transmission vacuum modulator tomorrow and see if it looks like either of them are missing or if they have vacuum lines that lead to nowhere. Thanks for the advice!