What to do if your Mercedes vacuum fails?
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. Disconnect the main fitting going to the brake booster while the engine is running using a 19mm wrench. Hook up your vacuum gage to the end and read the vacuum. As you can see we have a nice 22 hg of vacuum.
How does the Mercedes W123 vacuum lock system work?
When the solid yellow line that you have been testing under the hood enters the firewall, it continues on and passes through a rubber tube between the vehicle’s body and the door. Once inside the door, it connects to the center vacuum connector on the main vacuum switch. Steps 8 and 9 will include disconnecting vacuum lines from the switch.
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 is the vacuum system on a 722.3 Mercedes?
This variable vacuum system regulates the 722.118 series transmission shift. If the vacuum system is incorrect, the transmission could shift through the gears immediately or have late shifts. The variable vacuum system for the 722.3– and 722.416 series transmission regulates how hard or soft the transmission shifts.
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. Disconnect the main fitting going to the brake booster while the engine is running using a 19mm wrench. Hook up your vacuum gage to the end and read the vacuum. As you can see we have a nice 22 hg of vacuum.
When the solid yellow line that you have been testing under the hood enters the firewall, it continues on and passes through a rubber tube between the vehicle’s body and the door. Once inside the door, it connects to the center vacuum connector on the main vacuum switch. Steps 8 and 9 will include disconnecting vacuum lines from the switch.
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.