W124 climate control vacuum pod replacement - Page 10 - PeachParts Mercedes-Benz Forum

azurite300E · #**136** 05-30-2008, 11:22 AM

The MityVac manual says that vacuum in a normal engine should be a steady 16-22 inches, so 25 sounds a bit high... but I just realized we're talking about a diesel car that uses a separate vacuum pump, so maybe it's 25 inches after all.

driver8 · #**137** 05-30-2008, 03:01 PM

I just got the dash apart once again to reinspect everything. I noticed that in reassembling everything the first time, I forgot to put a retainer pin that holds the center air vent pod (?) to the flap back in - this is the pod which is inside the air box and opposite the square pod mounted outside, behind the acc unit, that controls the air going to the footwell flaps. Its shaft was retracted and stuck under the flap. I took off the passenger side vertical air shaft to get to it since reaching down behind the flap isn't feasible.

When I get it all back together I'll check everything with the MityVac. Thanks to everyone for your help!!

mia · #**138** 05-31-2008, 07:22 PM

my climate control doesn't seem to be hooked up. i will read this this thread looks like good info

brewtoo · #**139** 06-06-2008, 01:58 PM

Quote:

Originally Posted by gsxr

The 124 design makes it difficult to manually jam the center vent flap open. I would tap into the main vacuum supply line, and send vacuum to the center vent pod at all times, if you want it always open. That would be pretty simple to do. To mechanically force it open, you need to pull the dash and remove the top of the heater box, and get creative internally...

Seems like I remember that you can simply remove the lever from the pod and the center vent will stay open. You do it from right behind the glovebox. Pretty easy.

gsxr · #**140** 06-06-2008, 03:34 PM

Quote:

Originally Posted by brewtoo

Seems like I remember that you can simply remove the lever from the pod and the center vent will stay open. You do it from right behind the glovebox. Pretty easy.

Nope... the center vent pod is *inside* the heater box. You need to pull the whole dash to access that on a W124. See photos below.

What's accesible via the glove box opening is the defroster pod, and you can access the footwell pods by pulling the pushbutton unit out, but that's about it.

retmil46 · #**141** 06-20-2008, 12:39 PM

I found a quick and dirty fix for those PITA metal clips on the diverter and early twin footwell pods.

Turns out the plastic mounting legs are just the right size and hardness that they can be threaded to take a # 6-32 machine screw nut.

I took a # 6 nut and ran it down the legs by hand with a short socket and 3" extension, with a little pressure behind it to make the nut dig in and cut the threads.

Just finished doing this to my new diverter pod and installed it on the housing - worked like a champ.

Jeremy5848 · #**142** 08-02-2008, 01:13 AM

Quote:

Originally Posted by Gilles Kay

. . . The best web site I found for vacuum valve prices is www.***************. If anyone has a better website or price, please let me know.

This appears still to be the lowest price, plus free shipping if your order exceeds $50. For the four pods that require dash removal, the total is currently $157.22. If you add on (2) footwell pods ('86-early '87) and (1) defrost pod, the total is $277.06 for a complete set of pods.

OTOH, think what it would cost to have your mechanic do the whole job at $100/hour plus full dealer list for the pods! At least $1000, right?

One challenge in shopping for pods is that everyone uses different names for the pods and their functions. Some retailers use Mercedes part numbers but others don't and it's a real PITA to figure out which ones to order.

Given the increased cost of pods since this thread began, I plan to replace only the four pods that require dash removal plus any of the others that test bad.

While I have the dash off, I'll look for a way to 'wire' the center vents open all the time. I like Dave's idea of connecting the center vent vacuum pod to the main vacuum line because it can be done and undone at the vacuum distributor, without pulling the dash again.

Jeremy

Jeremy5848 · #**143** 08-02-2008, 01:53 AM

Here's Dave's list of pod part numbers, with red numbers keyed to the pods in the EPC diagram.

Quote:

Originally Posted by gsxr

Part number list:
======================================================
124-800-00-75 = Defroster pod (dual chamber) 125
124-800-02-75 = Center vent pod (single chamber, twist-on) 137
124-800-03-75 = Diverter pod (single chamber, small, attaches w/3 clips) 140
124-800-04-75 = Recirculation / fresh air pod 1 (dual chamber) 143
124-800-11-75 = Recirculation / fresh air pod 2 (dual chamber) 152

124-800-01-75 = Footwell pod (round, small, to VIN A289309, 1986 to early 1987, two required) 134
124-800-09-75 = Footwell pod (rectangle, from VIN A289310, late 87 through 95, one required) 134

azurite300E · #**144** 08-02-2008, 01:55 AM

Quote:

Originally Posted by Gilles Kay

The best web site I found for vacuum valve prices is www.***************. If anyone has a better website or price, please let me know.

Anyone shopping around for these Bear vacuum pods should also check at KOPerformance.com as it seems that their prices are lower even compared to ********AZ. For example last time I checked (about a month ago) 124-800-00-75 was $48.75 at KO, compared to $60.95 at AZ. The rest of the pod prices only differ less then $5 between those two sellers, but KO always had the lowest price. Take a look at my comparison table:

Prices Vacuum Pods (Behr): MercedesShop.com [***************] [[KOPerformance.com]]
--------------------------------------------------------------------------------------------------
124-800-00-75 = $70.56 [$60.95] [[$48.75[]
124-800-02-75 = $23.27 [$15.24] [[$14.32[]
124-800-03-75 = $33.81 [$32.90] [[$31.76[]
124-800-04-75 = $52.81 [$40.99] [[$35.74]]
124-800-11-75 = $49.98 [$40.96] [[$35.01]]

124-800-01-75 = $29.21 (1986-87) Two req. [$24.99] [[N/A?]]
124-800-09-75 = $36.26 (1987-95) One req. [$33.44] [[$28.95]]

Total parts for 1986 MY: $288.85 [$246.02] [[$215.58*]]

*= 124-800-0175 not available from KO, buy at ********AZ at $24.00 x2

Jeremy5848 · #**145** 08-10-2008, 07:20 PM

I checked the seven lines coming off of the distribution block in my '87 300D and found only #5 (defrost large lift) will hold a vacuum. All the others had some degree of leak. The lines for #3 (footwell) and #6 (diverter) will pump down to about 5" Hg. I was surprised that my system works at all (which it does) and wondered whether I was doing the test wrong -- nothing said here about doing it power ON or OFF, engine running or not, CCU buttons pressed or not, etc. If the lines from the distribution block go directly to the various pods, then I'm doing it right, right?

In any case, I'll probably buy a complete set of pods and replace all of them when I pull the dash to install my new-to-me uncracked dash.

Jeremy

Jeremy5848 · #**146** 08-10-2008, 07:29 PM

Quote:

Originally Posted by azurite300E

Anyone shopping around for these Bear vacuum pods should also check at KOPerformance.com as it seems that their prices are lower even compared to ********AZ. . .

I cannot find the vacuum pods in the KOPerformance web site. They have lots of heat and a/c stuff but if the pods are listed, they must be under an alias.

gsxr · #**147** 08-11-2008, 01:19 AM

Quote:

Originally Posted by Jeremy5848

I checked the seven lines coming off of the distribution block in my '87 300D and found only #5 (defrost large lift) will hold a vacuum. All the others had some degree of leak. The lines for #3 (footwell) and #6 (diverter) will pump down to about 5" Hg. I was surprised that my system works at all (which it does) and wondered whether I was doing the test wrong -- nothing said here about doing it power ON or OFF, engine running or not, CCU buttons pressed or not, etc. If the lines from the distribution block go directly to the various pods, then I'm doing it right, right?

By connecting a Mity-Vac directly to each line, you are bypassing the engine vacuum pump, ACC pushbutton control unit, and 7-port manifold switchover valve. No need for engine on, power on, etc. Apply vacuum to the pod, and it should open fully, and hold vacuum. Period. Make sure the connections and rubber fittings are all tight and not leaking.

Slow leakdown on a pod indicates a minor crack in the diaphragm, which may still allow the pod to function with the engine vacuum pump, since the engine pump can pull a lot of vacuum. But when the crack gets bad enough, the pod will refuse to work at all. That usually appears as not being able to pump the MityVac to any kind of vacuum at all, it leaks as fast as you can squeeze the handle.

Jeremy5848 · #**148** 08-11-2008, 02:03 AM

Quote:

Originally Posted by gsxr

. . . Slow leakdown on a pod indicates a minor crack in the diaphragm, which may still allow the pod to function with the engine vacuum pump, since the engine pump can pull a lot of vacuum. But when the crack gets bad enough, the pod will refuse to work at all. That usually appears as not being able to pump the MityVac to any kind of vacuum at all, it leaks as fast as you can squeeze the handle.

OK, that's what I thought, thanks. Except for the defrost pod, then, all of mine leak to some extent and several are completely shot. When I replace them, I'll take the old ones apart just to see.

azurite300E · #**149** 08-11-2008, 04:10 PM

Quote:

Originally Posted by Jeremy5848

I cannot find the vacuum pods in the KOPerformance web site. They have lots of heat and a/c stuff but if the pods are listed, they must be under an alias.

I located them individually searching by part number, not sure either under what category they are placed.

d2bernhard · #**150** 08-11-2008, 09:39 PM

Hello. 1986 300E with 245k mi. Center vents stopped opening in the Spring and stayed that way all summer. No big deal to me, not too hot and I have not been using AC much at all. Today, I go to AC and they open ! Then next start up they do not open. What does this mean? Another clue, when the vents have not been open it seems like it blows always maximum cold, even when I crank way up to red on the temp wheel and also turn fan down to low. Thanks All!

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