Since the original old style Bosch electric pumps are no longer available, Kent decided to come up with a good alternative. He went to work to adapt the newer style pump found on most Mercedes of the 1990s. Even if your current pump is "working," you should consider this replacement, newer style aftermarket pump that is less prone to leaking and has a higher flow rate.
Product Details
The kit includes the following:
- New electric later model coolant pump
- Wiring harness and connectors to adapt factory wiring to the newer pump
- Fuse holder and two fuses for added system protection
- Silicone lube and applicators to help with installation
- DIY video instructions x 2
See the new pump (on the right below)compared to the old pump (which is no longer available new). The new style has larger diameter nipples and no wiring plug coming off the back of the unit. Length and body diameter are nearly the same, so the pump motor will fit inside the original rubber mount.
One BIG advantage of this newer auxiliary pump is that it has a higher volume output. This will give quicker cabin temperature changes, as well as a significant improvement in holding a constant temperature, provided the other components in the system are working properly (temperature sensor, monovalve, climate control panel, and temp logic box, etc.).
Here you can see this pump installed in a 1984 W123 300D.
PLEASE NOTE: This can also work on the ACCII climate control from 1977 to 1981. The installation will be a little different from the video instructions, as they were filmed on a later model with ACCIII. You should be able to get it installed and wired in with a little extra effort.
NOTE: Kit revised on 3/9/26. The pump has been changed to a later style (same size) to accept a new wiring plug, as shown below. We even pre-wire the harness for you to save time.
Related Products:
Late R107, Late W123 and All W126 Heater Mono Valve Repair Kit
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.
Radiator and Heater Hose Pick Removal Tool SET
If you plan to change coolant hoses this is a must-have labor-saving tool. These are cleverly designed tools. I could not have done it better myself. I actually use to make a couple of different types before I found this set.
Fluid Maintenance - Radiator and Fuel Hose HD Pinch off Pliers
I have used a lot of different clamping tools over the years to prevent fluids from leaking out when removing coolant, fuel, or brake fluid hoses. Most work ok. Some are hard to use in tight places. Many do not stop every last drip from coming out of the hose.