So I bypassed the problematic servo without buying the kit!

[kmwillis1987]

So I finally decided to bypass the stupid servo on my 116, but I didn't want to buy one of those $80 kits. I ended up doing it for around $35 with stuff from the local parts store, and now I have full control over my heat which is awesome for the upcoming winter. I was thinking of putting up pictures and more info about how I did it, but before I go to the trouble, is anyone interested in the process?

[mercmad6.3]

Our aircons down here didn't come with a servo,but i'd be interested in how you bypassed it.

[cadurning]

ME too.

[meltedpanda]

good wrench , please provide data

[tyl604]

Ditto.

[kmwillis1987]

I'll get some pictures of what I did and try to post them tomorrow. The heat works great now!

[blackestate]

any update. I am starting to fight one from scratch on my 77.

[Oracle12345]

Originally Posted by blackestate

any update. I am starting to fight one from scratch on my 77.

just convert your system to manual climate control. A bit involved but worth it

[thorsen]

This can't be too hard of a deal. Universal heater valves are cheap enough. I drove my MGB for several years with a simple 1/4 turn ball valve and 1/2" barbed hose fittings from Home Depot. The car was mainly driven in the summer so I didn't want heat, and during the fall I had it if I needed (albeit I had to open the hood to turn it on).

Add a control cable to something like this and you can control the heat from inside of the car.
http://www.southernrods.com/categories/heating-and-cooling/heat-control-valves/products/product-873.html

[kmwillis1987]

Hey guys,
Sorry it took me so long to post a reply to this. It has been super busy around here. I did have a fruitful day at the junkyard today though, and I thought this would be a great way to finish it up. Anyway, here is what you do:

STEP ONE: Go to NAPA and buy heater valve #660-1141. If you don't have access to a NAPA, this is the same valve that they used on older Ford F-100s in the 1970's (1972 is a good year to use to find the part), and I realized that it would work perfectly for this application. You will also need a universal throttle/choke cable. I bought a 7ft one in case I want to change the setup later, but a 5 or 6 ft one would do. I also went to the hardware store and bought about 4 inches of copper piping; I think it was around 3/4 of an inch wide or so.

STEP TWO: Unattach the old servo so you can remove the hoses from it. The vacuum section of my servo is still good, meaning that I have control of all blower speeds, etc. If yours doesn't work like this, at least you will still have heat with the fan on defrost... You will also have to loosen the auxillary coolant pump.

STEP THREE: The hose that comes out of the auxillary pump, goes through the servo, and runs to the driver's side of the car is the one that you will want to install your heater valve on. The other hose is the one where the coolant returns to the engine from the heater core, so you will take the copper pipe and connect the two ends of the return hose. Basically, you will just take the servo's coolant nozzles out of the picture.

STEP FOUR: After you have bypassed the servo completely by installing the copper pipe between the two ends of the return hose and the heater valve between the two ends of the supply hose, reinstall the servo and the auxillary coolant pump. It takes some maneuvering of the hoses to put it back, but you really don't want the servo loose and rattling around under the hood. Now all that is left to do is run the choke cable to the valve. I ran mine through the throttle opening in the firewall, and drilled a small hole behind the carpet under the steering wheel for the pull knob. Just run the cable through, zip tie it down so it doesn't interfere with the operation of the throttle, and run it over to the valve. Look at the picture I took of the whole engine. The silver cable is the one that I installed. There is a cable holder on the valve, so clamp the holder around the throttle cable's casing, and then wind the cable itself around the valve lever.

STEP FIVE: Now that everything is attached, you should be able to control the flow of coolant by pushing or pulling the choke cable. My setup works fantastically, and I hope that some of you can use this info to get heat for the winter! Realize however that this is just advice, and that I assume no responsibility for the finished product, or anything that happens in the process. It took me about an hour to do in total, and I am very pleased with the results. Check out the pictures at the end of the post. Please let me know if you need any more info. Good luck, and let me know how it works for you!

[280EZRider]

Originally Posted by Oracle12345

just convert your system to manual climate control. A bit involved but worth it

I took your advice about 18 years ago. To this day, it's the best improvement I think I've ever made. And you're right: it's a bit involved but do-able