What to do if your Mercedes vacuum starts leaking?
Be very careful removing the 2 connectors from the supply line metering valve. The nipples are small and very fragile and prone to cracking. If one breaks you will have to replace the entire line. Its not very expensive, but if it is not is perfect condition, then it will leak. Next is the green vacuum dashpot for the transmission.
How to test a Mercedes W123 vacuum lock system?
Pull all three lines from the check valve and test it. Use your mouth to suck and blow in to the single connection side of the check valve. If you can suck AND blow, the valve is bad and will need to be replaced. If air will only travel one way, the valve is OK. Connect your hand vacuum gauge to the yellow line with the grey stripe.
Where is the vacuum tank in a Mercedes?
Vacuum tank is pictured, in trunk, under hat shelf. Move your vacuum pump to the yellow solid line with no stripes for the next step. With your hand vacuum pump connected to the solid yellow line, with no stripes, you can continue. Make sure the driver’s side door is closed, and turn the key to the lock position.
Why is my Mercedes vacuum door not working?
The metering valve is designed to restrict the vacuum going to this area. Replace the dashpot and the connector if necessary. Next we turn out attention to the big culprits to vacuum leaks. The door lock check valve. If this is leaking then the doors may work slowly or not at all.
The nipples are small and very fragile and prone to cracking. If one breaks you will have to replace the entire line. Its not very expensive, but if it is not is perfect condition, then it will leak. Next is the green vacuum dashpot for the transmission.
Where is the vacuum reservoir on a Mercedes?
The reservoir is located in the truck on the sedan models and behind the drivers front fender on other models. Closer view of the lines. Now we will check the supply to the check valve. This side will have full vacuum since it is supplying most of the lines that come through the firewall.
What’s the black line on a Mercedes vacuum?
The black line supplies the vacuum reservoir tank. Please note that you need to check the green line with the yellow stripe. This line is the most common line to have multiple leaks due to all the dash pod units controlling the HVAC system. If it leaks, just plug it off for now.
Why does my Mercedes Benz have a vacuum leak?
This is due to the extra unmetered air flowing through the oil filler port. If there is no change in the vehicle’s idle, then you probably have a vacuum leak somewhere in the system. Don’t forget to check places where vacuum leaks may not be as obvious, such as the oil filler cap, the dipstick and also the valve cover.
The reservoir is located in the truck on the sedan models and behind the drivers front fender on other models. Closer view of the lines. Now we will check the supply to the check valve. This side will have full vacuum since it is supplying most of the lines that come through the firewall.
The black line supplies the vacuum reservoir tank. Please note that you need to check the green line with the yellow stripe. This line is the most common line to have multiple leaks due to all the dash pod units controlling the HVAC system. If it leaks, just plug it off for now.
Is the Mercedes vacuum pump easy to rebuild?
They are easy to use and slip in and out of the connectors easily. Typical Mercedes diesel vacuum pump. They are very reliable and easy to rebuild if need be. The most common failure is the check valve and internal diaphragm. The very first thing I do is make sure we have a constant supply of vacuum.