RE: Way to find Vacuum leak?
an old post from year 2000 that might be of interest:
I had ordered a replacement part from Dodge that is supposed to correct the
'Wild Vents' problem. This is where AC/Heat air blowing out vents
mysteriously changes and comes out other vents. It is most prone to happen
when accelerating. I read that the cruise control can suddenly 'pop out' of
I haven't had the vents change wildly like that myself, but I have had the
'Defrost' setting refuse to work, then come on suddenly 10-15 minutes later.
Chrysler's 'Fix' is replacement part number 04677204.
I think there is a TSB on this.
I had seen the description of the problem in some automotive service
My local Dodge dealer told me they now had the part, and I went and picked it
up (plus a broken passenger side sun visor clip). Cost was $7.84
The replacement part turns out to be about the size of a 35 mm Film can and is
a small vacuum reservoir with a built in check valve.
The original part (4306923) was a tiny check valve about the size of the tip
of my thumb. These check valves are in the vacuum line connected to the
nipple just rearward of where the PCV valve hose connects on the passenger
side of the engine. Just behind this check valve the vacuum line T's off that
goes to the cruise control mounted underneath the battery.
But when I went to put it on, I found that the new part lacked the proper
rubber hose fittings to install it. The new valve 4677204 has 3/16 nipples.
The new valve comes with only one rubber reducing elbow which has a female 3/8
end, and the other end 3/16 female.
The original check valve 4306923 has 1/4 plastic nipple ends and has a 1/4
rubber female elbow on one end, and short length of 1/4 rubber hose on the
other. The new valve's 3/8 rubber elbow is wrong - too big to seal to the 1/4
nipple at the intake manifold.
I went back to the Dodge parts counter to ask for the proper rubber fitting to
make it work, but they said they didn't have them and suggested I would have
to go to a parts store. At the local Advance Auto I could not find exactly
the right fittings, but was able to put the new check valve on using slightly
Motormite Mfg. Vacu-Tite! pn 47411 rubber elbow with 9/64 and 7/32 id ends,
and Motormite Vacu-Tite pn 47411 rubber straight with 9/64 and 5/32 id ends.
Seems sloppy on Chrysler's part - but maybe later model Rams than a 1995 have
different sized vacuum hoses and manifold fittings ?