Newbie Help! Starting Vacuum Process '80 450SL - PeachParts Mercedes-Benz Forum

supercanuck · #1 02-26-2007, 01:12 PM

Good afternoon!

Well I am playing with my 1980 450sl piece by piece, and my next big project is to take a look at and try to fix the vacuum system in the car. I don't know much about these, but I do know that something must not be working properly b/c I am having issues with my central locking and Climate Control. I am not having any issues with starting/shutting off, etc etc.

So I have a couple of questions:

1) Can someone quickly describe or send me a resource that has general info on the vacuum system? From my understanding there are multiple systems in the car (one for the door, climate control, etc etc). Basically I'm looking for a quick tutorial or info to get a basic understanding of the system and how it functions.

2) Advice, tips, suggestions, etc for getting started with this? I know it is a long project, but I don't even know where to start. As I mentioned, I know there are some issues, but I'm not sure exactly what. Ideally, I'd like to just test all of the lines in the car and replace the ones that are leaking, etc.

Thanks so much for all of your help!

Zack

smallblock450sl · #2 03-01-2007, 08:02 PM

Quote:

Originally Posted by supercanuck

Good afternoon!

Well I am playing with my 1980 450sl piece by piece, and my next big project is to take a look at and try to fix the vacuum system in the car. I don't know much about these, but I do know that something must not be working properly b/c I am having issues with my central locking and Climate Control. I am not having any issues with starting/shutting off, etc etc.

So I have a couple of questions:

1) Can someone quickly describe or send me a resource that has general info on the vacuum system? From my understanding there are multiple systems in the car (one for the door, climate control, etc etc). Basically I'm looking for a quick tutorial or info to get a basic understanding of the system and how it functions.

2) Advice, tips, suggestions, etc for getting started with this? I know it is a long project, but I don't even know where to start. As I mentioned, I know there are some issues, but I'm not sure exactly what. Ideally, I'd like to just test all of the lines in the car and replace the ones that are leaking, etc.

Thanks so much for all of your help!

Zack

Zack....There is no quick awnser. Send me your email in my PM and i'll send you the best diagrams off my Mercedes service manual CD. If that will help, let me know. Sorry i thought i'd already quoted this, sorry for the delay. Dave

supercanuck · #3 03-06-2007, 01:42 PM

Thanks Dave. I actually already have the Service Manual, I was just looking for some information that I won't find there. Basically any tips, etc that people have who have experienced working on something like this.

Thanks again!
Zack

TX76513 · #4 03-06-2007, 02:33 PM

supercanuk - this might not be the answer that you want but; with the older cars it's quicker (and not that expensive) to replace all those ageing lines and suspect connectors and "t"'s.

supercanuck · #5 03-06-2007, 03:29 PM

Thanks TX. That is actually almost what I was looking to do. However, before I do that I'd like to have a better overall understanding of the vacuum system and how it's related to other functionalities in the car.

Also, from my understanding, there are separate vacuum systems...one for Climate control, one for interlock system, etc etc. Are those all truly independent of each other, or are they branches of one central system? I'm just looking for this kind of info or tutorials on understanding the system.

When I go to replace all of the lines, where is a good place to get them?

ctaylor738 · #6 03-08-2007, 08:28 AM

There are actually three ways vacuum is used. You have identified two - interlock and HVAC. The third is engine management. Vacuum is used to control the timing, open the EGR valve, and control enrichment.

The interlock and engine management work quite well as long as the lines and connectors are in good shape. Sometimes you run into problems with the actuators at the trunk, gas door, and door locks, but this problems are easy to track down. The HVAC is another matter because it is controlled by the servo, which is almost guaranteed to fail at some point and by an amazing collection of vacuum-activated valves and switches.

I think vacuum is fun to work with. It is cheap - all you need is a Mityvac and some rubber connectors, and safe - it won't shock you, catch on fire, or explode, and it doesn't smell.