Engine/Transmission (1994 - 1998) Oil in vacuum lines

[T-Bone]

Well, I took the truck in because the vents were stuck in defrost mode and just got a call from the dealer - $2444. 09 to fix it. The word is I have oil in the vacuum lines and need to replace the cruise servo, AC control head, recirc actuator door, defrost actuator door, vacuum harness, and the check valve on the vacuum pump and put in a seal kit. 16. 5 hours of labor.



I know there is a recall (Recall #720) for 1995 and 1996 model years, but nothing for my 1997. It bugs me that a simple seal can end up costing this much.



Any advise/help would be greatly appreciated. I am not set up to do this kind of work at home (no shop and it was zero this morning). Do just pony up the dollars?



Thanks,

T-Bone

 

[JWilkinson]

I have a 97 also and have had the same problem twice. First was fixed under warranty in 97. Last time, 02 dealer just replace the vaccuum control near the floor. Yes there was some oil but nothing was said about it. Dealer cost for the repair less than $150. 00. Still working. You might try someone else. Good Luck.

 

[T-Bone]

Thanks for the tip JWilkinson. I might try another dealer and see what they come up with. $150 is a bunch better than $2444. This dealer said they need to pull the dash to get at the actuators and that is the majority of the cost.



T-Bone

 

[JMauro]

i have a 97 that had oil in the lines though the only thing that doesn't work is the cruise. i "think" it's an issue with the check in the vacuum pump but not sure. i "think" mine had the updated check valve in it. all i did was to disassemble the vacuum system and blow the lines out. i also disassembled the heater control panel and cleaned it as well. to help prevent any further contamination i installed a plastic inline fuel filter on the outlet of the pump. it sucked in some but i figured the paper element in the filter would catch any oil and you'd be able to see it. it's worked so far and i don't see any signs of oil in the filter so my pump may have been upgraded and they just never cleaned the system out. if your somewhat mechanically inclined you can do this yourself if your careful and have the proper tools. i disconnected the control lines at the servos and blew from the control head out to them. the only thing i haven't addressed is the cruise and i figure the servo is probably toast. i think they had a TSB out on the for battery acid eating the vacuum line but mine is OK. the manafacture should have to make these repairs for free as it's a known problem for many years. i'd hate to see anyone screwed for $2500 on a job like this when it could probably be done for 1/10th of that price.

 

[T-Bone]

JMauro,



What all didn’t work when you had your problem? I am stuck on defrost, my cruise does not work, and the ABS light is lit. The dealer wants to replace some of the actuators. I guess I’m left with the dealer’s word that they are really bad…



Here is a list of the things replaced in the 1995/1996 recall. It mentions that vacuum operated components may fail due to oil contamination. I would hate to only fix some of the problems. But, at the same time hate to dump almost $2500.



T-Bone

 

[JMauro]

actually the only thing that didn't/doesn't work is the cruise. i wanted to clean out the system before it got any worse. i guess the oil could attack the rubber in the vacuum motors (and some of the fittings/lines) and cause them to be inoperative. as for the ABS light it was on in my truck when i brought it and the most common cause is a bad wheel speed sensor that's installed in the top of the axle housing (on my 3500). the sensor is about $30-40 if i remember. i would NEVER spend that kinda money to correct the problems you have listed, the most expensive part would probably be the cruise servo. if you can find a competent mechanic locally (good luck) explain the problem and see what they want to repair it. the first thing i'd do would be to check the vacuum motors (i think there's 3 or 4 of them) with a hand vacuum pump. if it takes someone longer than 15 minutes to replace the wheel speed sensor they're goofing off, as for the cruise i personally don't get too upset that it's inop but it depends what you use the truck for... i may fix it someday.

 

[T-Bone]

Thanks for the tips. The first report was that all problems were related. When I asked specifically about the ABS light, I was told it was the rear wheel sensor. I told them I can do that myself and they knocked $238 off the price. I asked the Assistant Service Mgr if there was any other way he could help me on the price and he knocked off another $309 to get the price down to $1900. I need to ask about fixing the cruise myself. Maybe this can save me some too.



The part that I am not comfortable doing is the actuators and the vacuum harness. After looking at the Service Manual, it appears the dash must be pulled to replace the actuator doors on the HVAC system. Is this correct? My understanding is that the majority of the cost is labor.



T-Bone

Ps. What really sucks, a friend of mine just scrapped a 1997 frame with the dash and all the components in it.

 

[dodge cummins]

dealers will always take you for a ride. don't go there when you are out of warranty.

 

[DPinkston]

the first thing i'd do would be to check the vacuum motors (i think there's 3 or 4 of them) with a hand vacuum pump.

Wise words, heed them. You may have vacuum leaks, weak spots allowing the hose(s) to collapse, or the hose(s) could be pinched somewhere. Changing the hoses, if that's you problem, should be able to be done without pulling the dash. Make sure your vacuum actuators are bad before replacing them. A little time invested in diagnosing the problem could save you a thousand dollars or more.

Danny

 

[Andy Redmond]

I have repaired this concern many times, usually without pulling the dash and changing all that they want too.



Get a new cruise servo, and the actuator that is lowest and nearest the throttle pedal (this is why the blower diverts the air to the defrost only). It can be replaced on the truck with out dash removal if your clever.



The cruise servo itself may be ok or may have oil in the rubber diaphram. The soft rubber vacuum supply line to the cruise servo may have collapsed prevnting vacuum from being able to stroke the servo, thus no cruise.



The ABS sensor in the diff is likely the problem. You maybe looking at $40 or so for the actuator, <$100 for the ABS sensor and $59 to $?? for a cruise servo. The DC only "revised" ck. valve is about $225 shop price. I have sourced a similiar cummins part and robbed the "guts" from the new ck. valve to "rebuild" the oem design on a truck like yours. The Cummins unit is too large to thread into your vacuum pump. I tried sourcing Metric bushings but gave up. . too expensive for no more of them than I would sell.



I'm an independant and I charge at least 8 hrs to pull a dash, so there's about $800 of the repair.



I like vacuum ck. valves available from the dealer, napa etc instead of the fuel filter inline to prevent future oil contamination.



Get some electronic contact cleaner, several cans to flush the piping, that you can get too. Start at the a/c dryer/accumalator and work towards the vacuum pump.



If you will update your "account" and tell us where you like we might be able to refer you to a quality independent or savvy TDR member who might work for cash etc. .



Good luck

Andy

 

[T-Bone]

Thanks for the continued tips!



Danny, thanks for the tips. I will try and test what I can. I hate to drop this kinda coin due to a problem caused by a $5 seal.



Andy, I am planning on doing the ABS sensor myself. Seems easy enough (even in the driveway in freezing temps!) And, I think I can do the cruise servo (I’m assuming this is under the driver side battery?). If I have oil on the rubber diaphragm, is it shot? I will check the line.



I think I can handle the actuator for the defrost only thing, too. The other actuator they want to replace is the outside/recirc door actuator. Where is this one? According to the manual, it’s buried behind the dash. Not sure how to test this one. I do have a Mityvac vacuum pump. Can I use this?



Do I need to worry about vacuum lines behind the dash? Or, are they all under the hood? I'm thinking I NEED to replace these due to contamination to prevent future problems.



One of my biggest hurdles right now is the outside temp. I do not have a shop and it was zero this am. I wonder if I can have DC do the vacuum pump and harness and I worry about fixing the parts I can get to. I have a Service Manual but I’m still concerned about my abilities and am not sure how to find the vacuum components to test them.



Help from someone would be greatly appreciated! I’m in Colorado Springs and I can pay cash or barter…I have two hub caps, a round of lug nuts, and a case of beer!



T-Bone

 

[Joe G.]

You might want to check to make sure that there really is oil in the vacuum lines. I had the same symptom with the vents as you have. It was that the vacuum line got hot and collapsed at the fitting just before it goes thru the fire wall on the passenger's side. The collapsed section was only about 1/2" long. All I had to do was clip it off. The cruise control may be an unrelated problem.

 

[T-Bone]

Good thought, Joe. I think I'm gonna go pick up the truck and do some checking on my own before I make a decision on having DC fix this one.



T-Bone

 

[Andy Redmond]

TBone:



>>>Andy, I am planning on doing the ABS sensor myself. Seems easy enough (even in the driveway in freezing temps!)



Warm the sensor with a hair dryer to and gently pry the sendor outta the diff after removing the retention bolt. The hairdryer should warm up the elect. connector too, plastic and cold don't do together.







>>And, I think I can do the cruise servo (I’m assuming this is under the driver side battery?). If I have oil on the rubber diaphragm, is it shot? I will check the line.



Carefully remove the line and hook it up to the mighty vac and start the truck, do you have 20 inches or so at the end of the line? If not, the problem is a collapsed or leaky line prior to this point. If so, likely dig out the servo or attach the mighty vac to see if it will stroke the servo reliably. I have a used one that works if money is tight. It does't belong to me, but I think $15 and freight and it would be yours.



Remove the battery and battery box for better access (don't forget the studs that hold the lower end of the box to the steel innerfender nearer to the headlamp)





>>I think I can handle the actuator for the defrost only thing, too.



Be very careful when squeezing the plastic retainer jaws on the defrost panel door or you'll break one, small ign. type "channel locks" or small needle nose pliers with 90 deg. tips work well.



>>The other actuator they want to replace is the outside/recirc door actuator. Where is this one? According to the manual, it’s buried behind the dash. Not sure how to test this one. I do have a Mityvac vacuum pump. Can I use this?



Buried and yes you can use the mighty vac.



>>Do I need to worry about vacuum lines behind the dash? Or, are they all under the hood? I'm thinking I NEED to replace these due to contamination to prevent future problems.



I can usually flush these enough in place to avoid future problems. The contact cleaner will dry much more slowly in the cold. An air compressor and blow gun with regulated air is likely in order to dry things with a few puffs.



You could also use "rubbing" alcohol, if it doesn't have to much water (freezing concern) and you have a way to shoot it into the tiny (1/8" id lines).



>>One of my biggest hurdles right now is the outside temp. I do not have a shop and it was zero this am. I wonder if I can have DC do the vacuum pump and harness and I worry about fixing the parts I can get to. I have a Service Manual but I’m still concerned about my abilities and am not sure how to find the vacuum components to test them.



Don't get in over your head if your worried, but you can remove each vacuum line starting at the vacuum pump and flush with a small amount of contact cleaner working your way up the the hydro boost (97 right?) then across the firewall just before firewall entry. Then over to the cruise and you've flushed 90%.



Maybe someone in the TDR member assistant list has a garage that maybe heated (or at least out of the wind)? Some folks advertise in the TDR from up on the Front Range side of town? How far is ATS? (The transmission guys? Wheatridge?)



With the cold any oil is going to be really sticky on rubber parts, of course its not much better in the extreme summer heat either.



>>Help from someone would be greatly appreciated! I’m in Colorado Springs and I can pay cash or barter…I have two hub caps, a round of lug nuts, and a case of beer!



T-Bone



Good luck

Andy

 

[T-Bone]

Thanks for all the help, Andy. It all seems to make good sense. I am wondering if I need to take care of the vacuum pump and check valve prior to doing anything else. Can I fix the pump and valve and take care of the rest of the problems as I get to them? i. e Replace vacuum lines as needed, replace actuators as I get to them? Seems I don't want to fix anything prior to correcting the leak that caused the problem.



T-Bone

 

[Andy Redmond]

TBone:



The problem lies in the ck. valve that threads into the vacuum pump that the 1/2" od (+/-) rubber vacuum hose is attached to ( on the side of the pump).



It is not necessary to remove the vacuum pump, just remove the ck. valve and once it is dis-assy, You will see a plastic or rubber ball, a spring and a tri cornerd plastic piece that act as a one way ck. valve ( allows a vacuum but seals out the engine oil that lubes the vacuum pump). Please be cautious in dissassy or your loose these little pieces, and I'll hear your &^**^( from Texas!



The cummins part no to repair your unit is :



3931558 vacuum pump ck. Ball valve $40-70



4883793AA vacuum pump ck. Ball valve/from dodge recall kit $198 +?



Good to the Dodgeram.org and read the recall and TSB on the 95-96 truck (you may have already) it gives some helpful illustrations.





Good luck

Andy

 

[T-Bone]

Thanks Andy. Your help is much appreciated! So, are you saying that I do not really need to replace a seal in the vacuum pump provided I do not see any oil on the outside of the pump? I read several posts about the vacuum pump leaking puddles of oil. I'm not sure if mine is leaking. I kinda assumed that I have an internal vacuum pump leak that caused the oil contamination problem when the check valve failed. If I can just replace the check valve, the problem seems much smaller.



T-Bone

 

[Andy Redmond]

External vacuum pump leaking has no relavence to the vacuum line contamination (oil). The vacuum pump has a rotor that spins which is gear driven from a gear in the gear housing. Three rubber swipers are centrifically thrown out to the inside bore around the rotor creating a seal and therefore vaccum. The external leak is caused when the seal gets hard and the ps pump shaft has grooved sufficently and then we have oil migration and a seep or drip or even a leak. Its never a good idea to have an oil leak, but functionally nothing happens other than it may puke more than the messy factor causing a larger oil leak. Any oil seepage attracts contaminates like dirt and causes greater wear on the power steering nose. If the engine is allowed to run low on oil from this obvious things happen. I change both together often, so a leak does not return quickly due to the groove in the ps pump nose.



I have a kit available should you desire to purchase one for less than the dealer.



Good luck

Andy

 

[rwarner]

Wise words, heed them. You may have vacuum leaks, weak spots allowing the hose(s) to collapse, or the hose(s) could be pinched somewhere. Changing the hoses, if that's you problem, should be able to be done without pulling the dash. Make sure your vacuum actuators are bad before replacing them. A little time invested in diagnosing the problem could save you a thousand dollars or more.

Danny

when i read this post i was reminded last summer i had similar problems and found that the rubber 90 at the vacuum pump was soft and collapsing from the vacuum. took it to the parts store to get a suitable more rigid replacement. $2. 00 blending doors fixed.

 

[T-Bone]

rwarner,



Thanks for the tip. I hope to do some checking tonight or this weekend. I noticed last night that I no longer have 4x4. Sounds like a good possibility.



T-Bone