Vacuum line coming from intake to alda - PeachParts Mercedes-Benz Forum

ggspeed · #1 01-17-2009, 01:53 AM

can anyone show me a photo of this?

I can't for the life of me figure out what or where it is and don't want to mess anything up.

I need to clean that line, but don't know where it is.

Jeremy5848 · #2 01-17-2009, 01:56 AM

Which car?

ggspeed · #3 01-17-2009, 02:11 AM

sorry 300SDL

BoomInTheTrunk · #4 01-17-2009, 02:39 AM

Search for "bango Bolt" the "bango bolt" is what needs to be cleaned out along with the line.

H-townbenzoboy · #5 01-17-2009, 02:44 AM

Quote:

Originally Posted by BoomInTheTrunk

Search for "bango Bolt" the "bango bolt" is what needs to be cleaned out along with the line.

Make that "banjo"

BoomInTheTrunk · #6 01-17-2009, 02:47 AM

Quote:

Originally Posted by H-townbenzoboy

Make that "banjo"

Thank you, its been a long day.

H-townbenzoboy · #7 01-17-2009, 02:49 AM

Quote:

Originally Posted by BoomInTheTrunk

Thank you, its been a long day.

No prob.

LUVMBDiesels · #8 01-17-2009, 06:34 AM

There is no banjo bolt on the SDL. The ALDA pressure line goes from approximately the middle of the intake manifold to the over boost switch near the rear of the left fender then to the ALDA on top of the injection pump under the manifold. Look for the plastic tube coming off the manifold and follow it. There is also a vacuum line going to the ALDA coming from the fender. The ALDA has a 't' fitting on it. The vacuum line bleeds off the pressure until the engine gets warm limiting boost.

On the OM 603 engine the ALDA is harder to find than on the 617. It is tucked under the manifold

My over boost switch was broken so I just removed the whole setup and plugged the port on the manifold.

ggspeed · #9 01-17-2009, 01:13 PM

I cleaned out the part on the overboost line and all its components and noticed some improvement.

I did some more research and found that there was another line that ran from the alda to somewhere, however i can't find it.

I could imagine that this would be a clogged up too so i wanted to do the it also.

I just need a pic or something because i have no idea where or what it is.

sixto · #10 01-17-2009, 01:36 PM

Quote:

Originally Posted by LUVMBDiesels

There is also a vacuum line going to the ALDA coming from the fender. The ALDA has a 't' fitting on it. The vacuum line bleeds off the pressure until the engine gets warm limiting boost.

Unless your car is setup differently, the split at the ALDA is a boost signal for the transmission vacuum amplifier. It goes to a vacuum switching valve triggered by the engine coolant temp sensor beside the thermostat.

There is a boost bleed feature by way of the air recirculation valve (ARV) on the turbo compressor housing but that's controlled by EDS, not manifold pressure.

Sixto
87 300D

sixto · #11 01-17-2009, 01:47 PM

This diagram will probably help more than a picture -

http://i323.photobucket.com/albums/nn447/Jeremy5848/1987%20Mercedes%20300D/Vacuum603.jpg

Some cars have a split at the VAC port of device 123. The split goes to a vacuum reservoir tucked in the left fender.

I'd tee in a boost gauge at the manifold then at the ALDA to see if there is a problem. If you see 10 psi or more out of the manifold, you don't have a problem or whatever problem you have isn't caused by a weak boost signal to the ALDA.

Sixto
87 300D

ggspeed · #12 01-17-2009, 02:20 PM

Some cars have a split at the VAC port of device 123. The split goes to a vacuum reservoir tucked in the left fender.

when you say left fender do you mean the driver side of passenger side?

I already cleaned the overboost on the driver's side, but was told there is a line coming off the firewall or the manifold (different sources said two different things) Essentially there is a bolt called a banjo bolt that needs to be removed and cleaned.

sixto · #13 01-17-2009, 02:44 PM

Left = US driver side

As LUVMBDiesels said, there is no banjo bolt in a 603 ALDA circuit. 617 turbos have a banjo bolt on the intake manifold. That's what you read about. What you should do is clean the manifold fitting the plastic hose attaches to. It takes a 12mm socket or wrench. It's very soft and will break with the slightest overtightening.

If you must clean a banjo bolt, there's a bunch in the primary fuel delivery circuit and a couple for transmission fluid

Sixto
87 300D

ggspeed · #14 01-17-2009, 02:58 PM

ok, so the only one's to clean on this engine are the two lines on the driver's side of the engine...

There is one running to the overboost protection valve, and one running back, cleaning those two is what needs to be done....

Maybe i'll try cleaning them better.

Thanks sorry about the confusion.

LUVMBDiesels · #15 01-17-2009, 03:37 PM

Clean out the switch as well. Just run some carb cleaner through it.

What I did was to remove the ALDA all together. Remove and plug the lines and take off the ALDA unit. There are posts on how to do this.

The EGR system and the ARV can be disconnected as well.

Just plug the vacuum lines going over to the right (passenger side) across the front of the engine.