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

[TXram1]

Noticed today while working on my 97 truck that I have oil in my vacuum lines. I will be flushing all th lines and hope no serious damage has been caused. The problem I am having is that I thought the check valve was in the main line coming off the vacuum pump, but i can't seem to find it. What does it look like and more importantly where is it.



Thanks,



Greg

 

[HEMI®Dart]

Greg,



Here is some more info on the problem. There are some diagrams too.



http://dodgeram.info/tsb/1997/D-97-10.htm

 

[TXram1]

update

I bought an electric vacuum pump for a ford to install. I could have gotten a new check valve assembly, but I believe there is something more wrong than just a check valve. My Dad's 96 just had a check valve installed about 1 year ago, and it never showed any signs of contaminating the lines. Would I be correct in my assumption, that something like an internal seal went bad.



Thanks,



Greg

 

[Andy Redmond]

No the check valve just prevents oil migration, if it goes on long enough the vacuum actuator for the vent/defrost diverter in the blower box will get killed. Its the one you can see the end of on the transmission hump and above the throttle pedal.



I have repaired several with this problem, get some contact cleaner and an air supply.



You might be able to rob the pieces out of this Cummins part to repair yours! Darn, I can't seem to find the part #. .



You might also source some one way ck. valves to go in the 3/8" hose after it leaves the vacuum pump?



Good luck

Andy

 

[Josparkz]

My truck was born w/o a check valve. I ended up getting everything replaced due to oil contamination.

 

[illflem]

Pre '96 with vacuum assist brakes are covered by a recall where the check valve is installed and the vacuum system warranty is extended to seven years.

I think part of the reason DC switched to hydro assist was to avoid the recall problem, if oil getting by doesn't effect safety like brakes it isn't covered by recall.