$27 part for upshift delay.....need confirmation

[neumann]

Hi,

I have a code 26, I am planning on replacing the upshift delay valve on top of the brake booster on driver side below the windshield. I need to order this (approx) $27 part that others have discussed. Can anyone help me? Is it O4045-70190 on FastLane website??

I have a 94 e320 vin WDBEA32E8RC078470

Thanks

[neumann]

http://catalog.eautopartscatalog.com/mercedesshop/quote.jsp?partner=mercedesshop&year=1994&product=O4045-12000&application=000290694


the part link on Fastlane is above.....anyone? I want to make the overnight delivery cutoff time

[mbdoc]

Just because you got code P1 700 or code 26, you may or most likely won't need the switch-over valve. THE code means that the trans didn't stay in gear long enough when the engine is cold. & that usually is a vacuum leak in the trans control pressure cable.

[neumann]

hi,

is the trans control pressure cable easy to access and is replacement advised?

[engatwork]

neuman - put the car on jackstands/ramps and look on the side of the tranny for a black vacuum line coming to it. Now trace that line to the engine compartment area, unhook it at a convienent location and pull a vacuum on it using a MightyVac. See if it holds vacuum. If it does not then you will need to troubleshoot that line to find the leak.

[neumann]

engatwork,

Thanks for the tip Would anyone have a photo of what to look for? As they say, "a picture speaks a thousand words".

[Arthur Dalton]

You can pull ther vac right at the outlet line of the SOV.. [ green line]. That goes to the cable element and is , as Doc says . more likely the problem than the SOV..

For testing , the system basically is this :

When cold and first drive cycle, the ECU sends a dc signal to the solinoid coil of the SOV. That opens the valve to allow engine vac to flow through it to activate the cable element at the trans.
[ which holds/delays the shift point ]

So , for testing, first see if you have vac at the SOV inlet line from the engine. IF not check that line back to the engine for a break/unplug.
If OK , then check the vac hold of the outlet line..
The next test is to "T" a vac gauge into the outlet line of the SOV
and watch the gauge w/test drive [ I tape gauge to windscreen]
If gauge shows vac for this test, you know that the SOV is recieving a sig from the ECU and the SOV is allowing vac flow..
If not , these two can be further tested by checking the 2 wire connector w/meter for power and gauge for flow with power
to tell if it is the SOV not recieving a sig or the SOV being energized, but not opening [ allowing flow],,
The code remedy/fault chart pushes you in the direction of shorted/open SOV, but that is rarely the case...
I only mention this cuz I see lots of members buy an SOV when not needed... plus knowing the basics of each system gives one
some ammo to fiqure the possibles out...

Also, As many of these are now being bought as used cars, it is good just to check the vac lines for blockage as many guys hate the delay and they put a 'BB" in the line [usually around the SOV in/out connectons] ...me being one