1985 300D: Is it a Federal or California? - Page 3 - PeachParts Mercedes-Benz Forum

Samuel M. Ross · #31 09-04-2007, 09:39 PM

I was contacted by Blaine off-FORUM and have been trying to help with this one... for as you can see in my signature below I have a 1985 CaCar W126 300SD in the extended family that I tend to when I can.

So let me throw out my inflated 2 cents worth about the restricted orifices that Blaine has. I started a THREAD about these and from this eventually evolved my theory that this 6 or more selection of little in-line plastic orifices were used by Mercedes as a means to do final "tweaking" [sp?] of systems so that they could standardize the off-car adjustments for the sake of mass production... and with this used the different orifices to "tweak" as needed on different models/years. So IF I'm correct, the bottom line on orifices is that the size needed is not necessarily specific to a year/model... they are used to either throttle down the vacuum FLOW or increase the FLOW as needed!??

I guess Blaine will now mostly be using the '85 Calif Vacuum diagram found on the PeterSchmid.Com website at:
http://www.peterschmid.com/vacuum/1977_1985/617_95/1985_cal.jpg
Once Blaine confirms that the above diagram is the official reference diagram he wants to use for this THREAD as we go forward, I would like to do some color coding such that it might just help us think more logically about the changes he will likely want to make on his strange "U.S." delivered that is mostly like a CaCar that somehow ended up in Canada!

Also Blaine... I have the CD manual for the W126 which includes about 100 pages of "Electrical" diagrams that might just come in handy on the electrical side of this "dilemma"!
Regards

Tubber · #32 09-05-2007, 08:28 AM

Thanks Sam, welcome aboard.

I will be using the 85 Cali diagram only because it includes the Vacuum Transducer and how it plumbs into the VCV. Today, I'm off to test the lines and fitings, and to see what state the VCV and possibly the Modulator is in. I'm armed with the knowledge gained here from the members.

I will update later.

Blaine

Jeremy5848 · #33 09-05-2007, 01:07 PM

Quote:

Originally Posted by Tubber

If I remove the vac converter and its switchover valve does this effect the control unit in any way?

Removing those parts should not affect the electronics. It is unlikely that the design is smart enough to know that a component of the overall system has been removed. I certainly have noticed no ill effects from removing 81 and 84 in my car.

By the way, #80 Control Unit must stay in the car or your tachometer will not work. The Control Unit uses engine speed as an input so the tach signal runs through it and then to the tach. The signal also may receive some processing so that what comes out of the RPM sensor is modified before it goes to the tach. Thus, you might not be able to wire directly from the sensor to the tach and get a meaningful result.

Quote:

Originally Posted by Tubber

Each works the same way? I know they both vent but considering my application has been called Federal, removing 81 and 84 won't effect the VCV at all? Do I simply just plug at 85(referring to 84 Fed diagram) if I remove 81 and 84?

If you remove 81 and 84, you can also remove filter 85 and pull the vent line out of the hole in the firewall. It isn't connected to anything on the passenger side, just hangs there under the dash, lurking, waiting to confuse newbies. ("I have a hose that isn't connected to anything under my dash...")

The factory manual "Model Year 1985/Passenger Cars/USA Version -- Introduction into service" (dated October 1984) says on page 79 that the only differences between the 85 Federal and California models are #80 Control Unit and #139 Trap Oxidizer (later replaced with "Trap Catalyst" in a factory recall program). The vacuum plumbing is the same on both versions and that would include your "British North America" version.

Note that in making this comment I am not including all the differences in manifolds, turbo mounting, air cleaner box, PCV hoses, etc., that are necessary to make room for the trap ox in the California versions.

Jeremy

Jeremy5848 · #34 09-05-2007, 01:12 PM

Quote:

Originally Posted by FRANKNBENZ

On the W123, then, so far in my meanderings about the engine room, I have found three vac check valves (pix in same order):
1. White, integral to the vac boost hose, subject of this thread.
2. Yellow, probably part of the "other vacuum consumers" cabal (and at least two are part of the heater control system on the W124).
3. Metallic, the check valve on the vac pump itself.

The white valve works correctly, I think. The yellow valve or valves must also work or the door locks wouldn't work with the engine not running.

The metal check valve in the pump may have failed or become blocked with some crud. I wasn't sure the pump even had one. I presume it is in line with the hard vacuum line and screwed directly into the pump? I'll take it apart and see what I can find.

Jeremy

Jeremy5848 · #35 09-05-2007, 01:19 PM

Quote:

Originally Posted by Samuel M. Ross

So IF I'm correct, the bottom line on orifices is that the size needed is not necessarily specific to a year/model... they are used to either throttle down the vacuum FLOW or increase the FLOW as needed!??

So your theory is that the orifices were inserted by the factory to tweak each engine to spec? Two different cars of the same model might have a different set of orifices? Most interesting!

Tubber · #36 09-05-2007, 07:09 PM

Excuse me if I'm quick here in order to get to the "good stuff"...

Quote:

Originally Posted by Jeremy5848

Removing those parts should not affect the electronics. It is unlikely that the design is smart enough to know that a component of the overall system has been removed. I certainly have noticed no ill effects from removing 81 and 84 in my car.

Gotcha...

Quote:

Originally Posted by Jeremy5848

By the way, #80 Control Unit must stay in the car or your tachometer will not work. The Control Unit uses engine speed as an input so the tach signal runs through it and then to the tach. The signal also may receive some processing so that what comes out of the RPM sensor is modified before it goes to the tach. Thus, you might not be able to wire directly from the sensor to the tach and get a meaningful result.

Good info...

Quote:

Originally Posted by Jeremy5848

If you remove 81 and 84, you can also remove filter 85 and pull the vent line out of the hole in the firewall. It isn't connected to anything on the passenger side, just hangs there under the dash, lurking, waiting to confuse newbies. ("I have a hose that isn't connected to anything under my dash...")

I guess that was for me....thanks I think

Quote:

Originally Posted by Jeremy5848

The factory manual "Model Year 1985/Passenger Cars/USA Version -- Introduction into service" (dated October 1984) says on page 79 that the only differences between the 85 Federal and California models are #80 Control Unit and #139 Trap Oxidizer (later replaced with "Trap Catalyst" in a factory recall program). The vacuum plumbing is the same on both versions and that would include your "British North America" version.

Jeremy, this is what I've waited for and a major reason for this thread; its especially nice to see it came from a MB factory manual. Finally, I know for sure what I have. Thats what was puzzling me, having the same vac setup as the Cali without the Trap Oxidizer and its related parts. Thanks!

See my next post for the vac system diagnosis I'm doing below. My 1985 Federal (had to say it) has shifting problems in the 1-2 and a clunkfrom 2-1 when stopping. I wanted to know if it was a Fed or Cali to put the system back to stock and diagnose where the leaks were/where the adjustments needed to be.

Now we can start the process

Blaine

Tubber · #37 09-05-2007, 07:18 PM

Ok, here are some updates and questions. Referring to 85 Cali diagram. I would like to run the original Federal setup first, then decide whether or not I'll eliminate the ARV, EGR, 84 and 81.

I checked the following vacuum lines and connectors. My method of checking was removing each(-) and setting my vac gauge to pressure. I then plugged up all the openings and submerged each section in a bucket of water. Applied pressure and looked for bubbles.

-Vent lines from both the vacuum converter(84) and vacuum converter switchover valve(81). I know these “vent” but I don’t want to leave any stone unturned. These lines and their connections were good. I’ve ordered a replacement inline filter as this one is dirty, however it appears there’s no oily residue in it.

-Vacuum line and connectors from Vacuum Converter to the EGR valve(60). All tight.

-Vacuum line and connectors from the Vacuum Converter switchover valve to the ARV(71). All tight.

-Vacuum line (supply) from the 3-way splitter to the Vacuum Converter switchover valve. All tight.

-Vacuum line (supply) and connector to the Vacuum Transducer(123). All tight.

-Three-way splitter with orifice (63b), Vacuum supply line and connector to Vacuum converter. All tight.

-Two 3-way splitters past orifice (63) from the supply line, lines and connectors to the “bottom” of the Vacuum Transducer Switchover Valve(125). Orifices (63) and (63a) are clear. I have discovered that the first 3-way split from the source has a loose opening at (63a). I plan to replace this 3-way splitter. I am also going to replace the vacuum line and connector from the 3-way splitter to the VCV dashpot as it has been “bastardized”. Dashpot (72) will also be replaced.

-Vacuum line and connectors to the Vacuum Transducer Switchover Valve(125) from the Vacuum Transducer(123). All tight.

-Pressure line from the Vacuum Transducer (123) to the Boost Pressure Aneroid (not numbered on the diagram but can be seen coming out from directly under the transducer), and pressure line from the Boost Pressure Aneroid to the Boost Pressure Aneroid Switchover Valve (126). Rubber connectors on each line are cracking so I will replace these. Pictures attached show the cracking.

- Vacuum line, Connectors and Dashpot (72) going from top of Vacuum Transducer (123) to the Modulator on Tranny. All tight.

-Orifices off the check valve are both clear.

At this time I do not have the above replacement parts, they’re on order so I moved onto checking the VCV and Modulator.

I removed the supply line from the VCV(65) and plugged my Mityvac into the line to the VCV without the dashpot in the line making sure my Mityvac was set to vacuum. I pumped the vac and achieved:

11 Hg at 0 seconds
10 Hg at 10 seconds
9 Hg at 40 seconds
9 Hg at 90 Seconds
8-9 Hg at 2 min
6 Hg at 5 min

Pumping 10Hg into the VCV again I opened the rack fully. The gauge drops to 0 Hg.

I opened the plastic dome on the side of the VCV gingerly with a pair of pliers to reveal the vacuum adjustment nut. I turned it clockwise slightly using a pair of visegrips (again very gingerly) as the nut is only flat on two sides so I couldn’t use a socket.

Pumping the vac again into the VCV I achieved:

14 Hg at 0 seconds
12 Hg at 1 minute
10 Hg at 2 minutes
9 Hg at 3 minutes
7-8 Hg at 6 minutes

Is this now an acceptable reading, or is the VCV supposed to hold vacuum? I found a qoate on this:

“For old style VCV’s, PN:1230700046 (its printed on top of the VCV). He said that: They are supposed to bleed a little bit even when closed. The spec is an average of 1 mmHg per second. Max bleed per second is 3 mmHg. Based on testing 10 of these things I have to believe this to be true. I now have one from an ‘85 TD that falls within this spec.”

Sorry, I dn't have the thread for the qoute, I'll try to find it again.

If this is true (not knowing if the above VCV is the same condition as mine now) are my “vacuum loses” normal, or does this indicate a VCV replacement?

I then tested the Modulator by disconnecting the source vacuum from the bottom of the Vacuum Transducer (123) and plugging it in to my Mityvac set on vacuum. I pumped the Mityvac and achieved:

18in Hg at 0 seconds
17in Hg at 30 seconds
17in Hg at 1minute
17in Hg at 1 min 30 seconds
17in Hg at 2 minutes
17in hg at 5 minutes

I believe that the Modulator is holding good vacuum.

Sorry for the long post, I hope you guys stuck with it.

Thanks

Blaine

Tubber · #38 09-05-2007, 09:16 PM

Showing the cracked pressure lines.

And what is this vacuum line coming from the drivers side of the VCV? BTW, I took this photo when I took the plastic dome off the side of the VCV to adjust it, so I realize its missing, it isn't MIA!

Thank you again,

Blaine

Tubber · #39 09-05-2007, 10:02 PM

Quote:

Originally Posted by Tubber

“For old style VCV’s, PN:1230700046 (its printed on top of the VCV). He said that: They are supposed to bleed a little bit even when closed. The spec is an average of 1 mmHg per second. Max bleed per second is 3 mmHg. Based on testing 10 of these things I have to believe this to be true. I now have one from an ‘85 TD that falls within this spec.”

Found the quote from this thread, its on page 11 at:

It's CRITICAL... how you set your transmission's vacuum system on your diesel MBZ...

I didn't see that anyone disagreed with it.

And the line coming from the side of the VCV (picture; circled in green) is a vent.

Blaine

Jeremy5848 · #40 09-06-2007, 11:23 PM

I did some sleuthing and discovered that the vacuum control valve (VCV) on the IP leaks. I can pump all I want with MityVac and it never gets below about 10 inches Hg. The leak is what drains my vacuum system when the engine shuts off. (The check valve in the pump and all other components, hoses, check valves, etc. are OK.) The vacuum hose and the vent hose on the VCV are both in good condition. When I put vacuum on the VCV, I can hear a scraping noise from the VCV as if a plastic piston and a metal spring were rubbing inside a plastic cylinder.

Questions for the experts:
The VCV is mentioned many times in the FSM but they don't really talk about it.
(a) what does the VCV do -- how does it work -- what does it do to control the transmission?
(b) what happens if it doesn't work correctly?
(c) does it matter if it leaks? Does the leak prevent it from working properly? My tranny shifts correctly (as far as I know, with my limited experience).

Is the VCV serviceable? The picture in FastLane shows a couple of screws holding the VCV together.

If the VCV needs to be replaced, so be it, but it is $116, not a trivial purchase.

Jeremy

Tubber · #41 09-07-2007, 08:38 AM

Quote:

Originally Posted by Jeremy5848

I did some sleuthing and discovered that the vacuum control valve (VCV) on the IP leaks

.

Jeremy, I'm not sure if I even qualify to answer some of your questions, but I'll try. In my above post I found some info saying that the VCV can leak vacuum and is normal according to some people. The thread and page are listed. When you apply vacuum only to your VCV with the Mity, what are the results? I posted my results in my previous post, are yours the same?

Quote:

Originally Posted by Jeremy5848

(a) what does the VCV do -- how does it work -- what does it do to control the transmission?

.

My understanding it changes the amount of vacuum to the transmission in sync with "throttle" response. More throttle/higher rpm; the lower the vacuum signal. At idle the tranny gets the "max" amount of vacuum set by the VCV, and the higher the rpm/throttle the lower the vacuum signal by the VCV. I think you are talking about a 1985 300(?), also puting into the mix your vacuum transducer. I haven't seen anyone properly state how the vacuum transducer (also referred to as vacuum amplifier) works (perhaps I haven't found it yet in my searches), so I can't comment on how the VCV works in conjunction with the transducer/amplifier.

Quote:

Originally Posted by Jeremy5848

(b) what happens if it doesn't work correctly?

.

Again, no experience, but given its purpose, it probably doesn't give the modulator the correct vacuum signal in response to throttle/rpm

Quote:

Originally Posted by Jeremy5848

(c) does it matter if it leaks? Does the leak prevent it from working properly? My tranny shifts correctly (as far as I know, with my limited experience)

.

Again, my above research seems to indicate that VCV's are supposed to leak; see the reference thread above which specifically speaks about an 85 TD VCV.

Quote:

Originally Posted by Jeremy5848

Is the VCV serviceable? The picture in FastLane shows a couple of screws holding the VCV together.

No idea here, but I have taken my VCV off the IP and opened the cover (two screws). There doesn't appear to be anything really serviceable; theres a rolled up spring in there. The side with the two screws doesn't even have a rubber seal or anything.

For what its worth,

Blaine

Tubber · #42 09-07-2007, 09:00 AM

Ok, so heres where I'm at. My check valve nearest the brake booster on the main vac line from pump was blocked, so I decided to drill it out. Used too big a bit (I know you're supposed to use a 1/16 I used one slightly bigger.....crap). So I replaced the brake booster line with the line from the '84 300D. Plumbed the system up as per the 85 Cali diagram (minus trap oxidizer and related stuff).

Discovered that the vacuum converter (84) was leaking/stealing vacuum somewhere. Decided to take that, the switchover valve (81), vent filter(85) off as a unit and plug up the EGR and ARV. Then I decided to "convert" the system to a 1984 Federal setup minus (84) and (81); meaning I also took out the vacuum transducer (well, its still there, not hooked up though)

Took it for a drive; the clunk from 2-1 is gone and it shifts MUCH smoother. As 2-3 shifts early I plan to adjust the VCV to 8-9 in Hg (seen Brian Carlton advise this as it works nicely on his SD) and then if needed adjust the modulator. As well, clean the banjo bolts/lines to and from ALDA and manifold. I'd like to adjust the kickdown cable.

Questions:

1) See as I don't have the tranducer hooked to the vacuum system anymore, will that effect the ALDA? I'm going to read posts on removing the ALDA but I just want to know for now.

2) Is the kickdown cable the one atop the valve cover with the black ribbed rubber cover over a wire? If so, and I see that it can be adjusted in or out by turning CC or CCW. I have read the Wiki article on doing this, but don't understand what state the cable is in to take out the "slack". With engine off, do you rotate the "throttle" linkage to reflect wide open throttle and at that point adjust the cable to take out slack, or do you adjust the cable to take out the slack when the "throttle" is at idle. I'm more inclined to think the first (wide open throttle) than the latter. Currently, my 300D doesn't kickdown when the pedal is pressed to the floor.

Will update when the work is done,

Thanks
Blaine

Jeremy5848 · #43 09-07-2007, 11:23 PM

Quote:

Originally Posted by Tubber

Jeremy, I'm not sure if I even qualify to answer some of your questions, but I'll try. In my above post I found some info saying that the VCV can leak vacuum and is normal according to some people. The thread and page are listed. When you apply vacuum only to your VCV with the Mity, what are the results? I posted my results in my previous post, are yours the same? Blaine

At first glance, my results are the same as yours. I didn't think to try moving the throttle linkage to see if the vacuum would change. I'll try that tomorrow. At the moment, I think my VCV is OK. The transmission works correctly, after all.

Samuel M. Ross · #44 09-14-2007, 09:00 PM

Oops... this went out before I intended!
Regards,

Samuel M. Ross · #45 09-14-2007, 09:06 PM

Quote:

Originally Posted by Tubber

.
Jeremy, I'm not sure if I even qualify to answer some of your questions, but I'll try. In my above post I found some info saying that the VCV can leak vacuum and is normal according to some people. The thread and page are listed. When you apply vacuum only to your VCV with the Mity, what are the results? I posted my results in my previous post, are yours the same?
My understanding it changes the amount of vacuum to the transmission in sync with "throttle" response. More throttle/higher rpm; the lower the vacuum signal. At idle the tranny gets the "max" amount of vacuum set by the VCV, and the higher the rpm/throttle the lower the vacuum signal by the VCV. I think you are talking about a 1985 300(?), also puting into the mix your vacuum transducer. I haven't seen anyone properly state how the vacuum transducer (also referred to as vacuum amplifier) works (perhaps I haven't found it yet in my searches), so I can't comment on how the VCV works in conjunction with the transducer/amplifier.
Again, no experience, but given its purpose, it probably doesn't give the modulator the correct vacuum signal in response to throttle/rpm
Again, my above research seems to indicate that VCV's are supposed to leak; see the reference thread above which specifically speaks about an 85 TD VCV.
No idea here, but I have taken my VCV off the IP and opened the cover (two screws). There doesn't appear to be anything really serviceable; theres a rolled up spring in there. The side with the two screws doesn't even have a rubber seal or anything.
For what its worth,
Blaine

Jeremy & Blaine,
Although I have not worked on anything newer than our two 1980 models, let me confirm that the same vacuum valve [aka vacuum control valve (VCV)] is specified for all of these cars so maybe my experience here can be of help. Namely that I have found two basic styles of VCV(s) under the same P/N and one is obviously made to be readily adjustible and the other is adjustible but it is not so obvious... but I have adjusted both styles and have some photos that help tremendously in explaining how to make the adjustments.

Also, let me assure you that it is entirely normal for a VCV [off the car] to not hold a vacuum!

Got to go to dinner... but will check back later to see IF I am on a track to be of help!
Regards,