Late R107, Late W123 and All W126 Heater Mono Valve Repair Kit

A torn diaphragm in the heater control monovalve is the number one reason for sporadic cabin heat, but it is not the only reason! With Kent's video tips, it is easy to install.

This fits the U.S. models with automatic climate control which include the 1982 to 1989 R107 380SL, 500SL, and 560SL + the 1982 to 1985 W123 ALL models + the 1981 to 1991 W126 sedan and coupes. This is an easy fix that you can do yourself. You may have to drain about a gallon of coolant out of your radiator before removing the valve. A sharp-angled tool is included to help you remove the old parts from the valve. In Kent's video instructions, he will show you how to remove the valve from a W123 ( valve locations are in slightly different locations on the R107 and the W126), take it apart, install the new parts correctly, and assemble it back together into the car.

Late R107, Late W123 and All W126 Heater Mono Valve Repair Kit
Free Add-Ons Included:

1982 to 1991 107 123 126 Mono Valve Repair Kit Installation - On Demand Video

Product Details

Here is the complete assembly removed from the plastic housing on the firewall. This part is the same on all related models but location along the firewall can vary. A 1983 W123 300D is shown here. The diaphragm Kent is pointing to is completely torn.

The unit can be tested on the bench with 12-volt power. Kent will demonstrate that in his video instructions.

The kit includes a new diaphragm assembly, a spring washer, new clips, and spacers. a sharp pick tool and detailed instructions on how to do this yourself. 

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