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Cost to replace entire vacuum system?

Started by UOnlyLiveOnce, 04 September 2022, 09:09 AM

UOnlyLiveOnce

I purchased a 1980 450 SEL in May.  The vehicle runs great but has been littered with climate control issues and vacuum leaks, causing my mechanic to implement workarounds that still end up being very costly. We've fixed some vacuum leaks, but the doors don't automatically lock, the top vents don't automatically open/close based on the climate control settings, etc.  And just the other day the climate control settings all stopped working except for defrost, which points to vacuum leak issues (still hear the servo working).

I'm at the point where I'm considering biting the bullet and replacing the entire vacuum system.  How much should I expect to pay for this?  I'm in Austin, Tx and my current mechanic, who is regarded as top tier MB mechanics in Austin, tends to be very pricy.  I'd like to shop this around but would want to have a target price.

Thanks everyone.

rumb

"Replacing"  would be an unnecessary and costly endeavor. The Vac lock system is really quite simple, but has quite a few components. Using a Mitivac with gauge, start in the drivers door. Check the black 3 way valve first. ( https://www.ebay.com/itm/224731700491)
  Then pull the rubber lines from each side of the diaphragms and see if they leak. Replace as needed.  Then go onto the passenger front door, then the back doors. Next do the gas tank lid and the trunk lock.

The entire door lock system is fed from the Yellow vac line near the fuse box.  There is a check valve there also.

There is also a vacuum tank in the trunk, sometimes that rubber connector wears out and can leak there.

You dont have to replace the entire vac actuator, just the Diaphragms.

Here is the instructions in the manual: https://handbook.w116.org/Chassis/80-CentralLocking/
 
New:
https://mercedessource.com/store/1973-1980-vacuum-door-lock-actuator-diaphragm-repair-kit

While the door panels are off it is a good time to lubricate the window regulator and tracks and also lube the door handle and the door lock. Door hinge pins lubrication is usually sorely neglected. The regulator use spray lithium grease on the regulator pivot pin. Use a light lubricant  on the slider.
001-989-37-51-09 is an excellent light grease for the tracks.
002-989-06-51-09 is an excellent door lock spray lube.



The door handles come off quite easily.  Remove the oval black plug on the side of door, remove 2 bolts and then just push the handle forward.  A cleaned and lubed handle feels fantastic when opening the doors.

I'd think a good mech could do all of the above for 8 hrs or less.

If you are even a bit handy with tools this is a fairly simple way to get to know your car.

If you proceed yourself we can provide info on removing door panels, or use the Technical Link at the top right of each page.  look for the maintenance manual. https://handbook.w116.org/Chassis/72-Doors/


BTW please post pictures of your car!
'68 250S
'77 6.9 Euro
'91 300SE,
'98 SL500
'14 CLS550,
'16 AMG GTS

raueda1

First, welcome to the asylum!  And congratulations on your new toy. 

That said, your post presents some challenges.  Pretty much everybody here on W116.org is a DIY type.  Many are skilled and trained mechanics, others (like me) are hard core hobbyists that seem to often do more harm than good to our cars.  ???  The point being that it would be a long shot that somebody knows a mechanic in Austin to recommend, but maybe you'll get lucky.

So, to your problem.  Many of us have suffered vacuum problems of different kinds (try search).  It isn't a vacuum system, it's several vacuum systems that are more or less isolated from each other.  Problems may be hard to pin down but the systems absolutely ARE amenable to systematic troubleshooting.  I don't know anything about the A/C but the door lock system isn't bad at all.  .  There are numerous threads here on the topic.  So, if your mechanic is doing workarounds he may not be so great after all.  And simply replacing everything really doesn't make sense IMO.  Would this include all the tubing, for example, when the respective Y's and components can be tested? 

Seems to me that if you're going to drive one of these cars then you're best off learning how to do this kind of thing yourself unless you have huge sums of $$$ to spend.  And even if you do, there's little guarantee that it will be $$$ well spent.  Hopefully others will comment and maybe even know a good mechanic in your area.  Good luck and cheers,
-Dave
Now:  1976 6.9 Euro, 2015 GL550
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0

UOnlyLiveOnce

Thank you for the details.  Unfortunately right now I just don't have the time to spend on vacuum leaks but am fortunate enough to have the funds to have them addressed by a professional. I'd love to be able to take this type of task on as a DYI project as my time frees up a bit in the future so I really do appreciate the details and will save them for future repairs.

The leaks seem to not only be in the locking system, but in the climate control system as well, which is more of a concern of mine. I don't necessarily care about locking the doors, but I do care that the climate control system functions properly, and right now the only setting that actually blows air is defrost.

So I'm gathering that this type of job is likely better served as a DYI task as it could take hours for a mechanic to leak test all the lines, which is fairly trivial, but costly to have someone else do. And maybe there's just no way to estimate how long this will take for a mechanic to find the leak.






UOnlyLiveOnce

#4
I couldn't get embedded photos to work from Google Photos but here are a few links to photos of the vehicle.

https://photos.app.goo.gl/MzmN1odXbieW3XX48
https://photos.app.goo.gl/7QFM8c2au3kSiQhW8
https://photos.app.goo.gl/mTyo1WH1b2BvCskV8

Jan S

Quote from: rumb on 04 September 2022, 01:44 PM"Replacing"  would be an unnecessary and costly endeavor. The Vac lock system is really quite simple, but has quite a few components. Using a Mitivac with gauge, start in the drivers door. Check the black 3 way valve first. ( https://www.ebay.com/itm/224731700491)
  Then pull the rubber lines from each side of the diaphragms and see if they leak. Replace as needed.  Then go onto the passenger front door, then the back doors. Next do the gas tank lid and the trunk lock.

The entire door lock system is fed from the Yellow vac line near the fuse box.  There is a check valve there also.

There is also a vacuum tank in the trunk, sometimes that rubber connector wears out and can leak there.

You dont have to replace the entire vac actuator, just the Diaphragms.

Here is the instructions in the manual: https://handbook.w116.org/Chassis/80-CentralLocking/
 
New:
https://mercedessource.com/store/1973-1980-vacuum-door-lock-actuator-diaphragm-repair-kit

While the door panels are off it is a good time to lubricate the window regulator and tracks and also lube the door handle and the door lock. Door hinge pins lubrication is usually sorely neglected. The regulator use spray lithium grease on the regulator pivot pin. Use a light lubricant  on the slider.
001-989-37-51-09 is an excellent light grease for the tracks.
002-989-06-51-09 is an excellent door lock spray lube.



The door handles come off quite easily.  Remove the oval black plug on the side of door, remove 2 bolts and then just push the handle forward.  A cleaned and lubed handle feels fantastic when opening the doors.

I'd think a good mech could do all of the above for 8 hrs or less.

If you are even a bit handy with tools this is a fairly simple way to get to know your car.

If you proceed yourself we can provide info on removing door panels, or use the Technical Link at the top right of each page.  look for the maintenance manual. https://handbook.w116.org/Chassis/72-Doors/


BTW please post pictures of your car!


Fantastic - thanks, Robert!

This will be my late fall job. Looking forward to it.
1975-mod W116 450 SE with 6.9 engine

raueda1

Quote from: rumb on 04 September 2022, 01:44 PM"Replacing"  would be an unnecessary and costly endeavor. The Vac lock system is really quite simple, but has quite a few components. Using a Mitivac with gauge, start in the drivers door. Check the black 3 way valve first. ( https://www.ebay.com/itm/224731700491)
  Then pull the rubber lines from each side of the diaphragms and see if they leak. Replace as needed.  Then go onto the passenger front door, then the back doors. Next do the gas tank lid and the trunk lock.

The entire door lock system is fed from the Yellow vac line near the fuse box.  There is a check valve there also.
There is also a vacuum tank in the trunk, sometimes that rubber connector wears out and can leak there.
You dont have to replace the entire vac actuator, just the Diaphragms.
Here is the instructions in the manual: https://handbook.w116.org/Chassis/80-CentralLocking/
 
New:
https://mercedessource.com/store/1973-1980-vacuum-door-lock-actuator-diaphragm-repair-kit

While the door panels are off it is a good time to lubricate the window regulator and tracks and also lube the door handle and the door lock. Door hinge pins lubrication is usually sorely neglected. The regulator use spray lithium grease on the regulator pivot pin. Use a light lubricant  on the slider.
001-989-37-51-09 is an excellent light grease for the tracks.
002-989-06-51-09 is an excellent door lock spray lube.

The door handles come off quite easily.  Remove the oval black plug on the side of door, remove 2 bolts and then just push the handle forward.  A cleaned and lubed handle feels fantastic when opening the doors.

I'd think a good mech could do all of the above for 8 hrs or less.

If you are even a bit handy with tools this is a fairly simple way to get to know your car.

If you proceed yourself we can provide info on removing door panels, or use the Technical Link at the top right of each page.  look for the maintenance manual. https://handbook.w116.org/Chassis/72-Doors/

BTW please post pictures of your car!
Great writeup Robert!  One comment though - The 8 hours might be real IF (and it's a very big IF) everything goes perfectly.  But then add in the time to source the parts, rebuild actuators, etc.  I've had frozen door handle nuts that didn't survive their removal etc etc.  Then what should be a 2 minute unscrewing becomes a 45 minute ordeal.  We've all had stuff like that.  And while we're in there, is the window frame aligned right and does the slide piece need replacement?  More time.  All of which goes to my point.  This is a great DIY job.  But, actual time can't easily be guessed at.  I shudder at finding a mechanic to do it at $100/hr or whatever.
-Dave
Now:  1976 6.9 Euro, 2015 GL550
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0

UOnlyLiveOnce

You have all convinced me to start tinkering a bit. I'm seeing some pretty worn vacuum hose connectors. Where should I look to get new connectors and start replacing them?

raueda1

You may need some of these.  Pelican is a good resource:
y-splitter

You'll also need one of these (or equivalent).  Handy for many things!
vac pump

Robert nicely outlined the process.  Do a little googling too.  You're not the first to do this so there's a lot out there.  Good luck!
-Dave
Now:  1976 6.9 Euro, 2015 GL550
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0

rumb

Just buy some rubber hose at the parts store and cut to lengths.
'68 250S
'77 6.9 Euro
'91 300SE,
'98 SL500
'14 CLS550,
'16 AMG GTS

Jenno1981

Great thread 👍 also convinced me to to tackle myself instead of procrastinating further...
1978 450SEL - Green
1999 ML430 - Also green 🤷�♂️