Need help restoring a 1963-66 STV valve for factory C60

[Claus S.]

I have never tried to restore an STV valve or anything like it before so can any tell me if this is the correct way to restore the STV valve for my car

I am thinking of replacing the piston and diaphragm assembly. Part number 7 on the picture
I have a new piston and diaphragm but the diaphragm is a little vavy but i am sure that will be okay when i put the STV valve back together

After that i will change the o rings where the red arrows is pointing towards on the picture Is there an o ring where the blue arrow is pointing towards? Number 2 on the picture

I will change the needles part number 3 and 6 if i can get them

The seal part number 15 for the absolute vacum regulator was not in the repair kit for the STV valve i bought so i will need to reuse the

[Wayne M.]

Re: Need help restoring a 1963-66 STV valve for factory C60

Claus -- all the Frigidaire pistons have wavy gaskets.

[Claus S.]

Re: Need help restoring a 1963-66 STV valve for factory C60

Wayne. I suppose the diaphragm is placed correct on the piston ready to be put in the STV valve like it is on the picture below

[Mike G.]

Re: Need help restoring a 1963-66 STV valve for factory C60

Roger: the rubber needs to be shaped like Wayne's photo so the metal cup fits into the recessed area.The '65 shop manual supplement (maybe the '64 too?) has the complete sequence to overhaul your STV. It calls for applying a light film of grease to the rubber where it seats in the cup. Powdered graphite works as a substitute and is easier to find. Don't forget to lightly oil the piston with the same oil you are putting in your system. 525 viscosity mineral oil for an R12 system.When you change the valve cores, don't use bicycle valve cores. Get some that are designed for A/C systems.You should be fine with re-using the pressure regulator seal. That's what everybody does, I believe.Pay attention during reassembly to the step where you push on the piston to seat it BEFORE you final tighten the screws. That makes sure it isn't pinched.You should be fine. Go for it.Mike

[Gary J.]

Re: Need help restoring a 1963-66 STV valve for factory C60

Be careful when separating as it will be under pressure. Also a tic mark for realignment purpose.

I would like to know if there would be any way to test the unit upon reassembly before installing on the car.

[Claus S.]

Re: Need help restoring a 1963-66 STV valve for factory C60

When you say metal cup do you meant the spring retainer cup?
I suppose that the diaphragm is place correct in the piston now?
See the pictures to check if i have placed the diaphragm correct on the piston this time?
The way the diaphragm is placed on the piston on the pictures now is how it was when it out of the box

[Harry S.]

Re: Need help restoring a 1963-66 STV valve for factory C60

I have never tried to restore an STV valve or anything like it before so can any tell me if this is the correct way to restore the STV valve for my car

I am thinking of replacing the piston and diaphragm assembly. Part number 7 on the picture
I have a new piston and diaphragm but the diaphragm is a little vavy but i am sure that will be okay when i put the STV valve back together

After that i will change the o rings where the red arrows is pointing towards on the picture Is there an o ring where the blue arrow is pointing towards? Number 2 on the picture

I will change the needles part number 3 and 6 if i can get them

The seal part number 15 for the absolute vacum regulator was not in the repair kit for the STV valve i bought so i will need to reuse the

I just took apart an NOS 64 STV and YES there is an o-ring between part 2 and the main body.

[Claus S.]

Re: Need help restoring a 1963-66 STV valve for factory C60

Thanks Harry Then i know that i have to put a o ring there as well
In the STV valve restore kit i bought there is 1 small special washer that can not see where iy is supposed to be placed in any of the diagrams for the STV valve i have
Any here knows where this small washer in the picture below is supposed to be placed in the STV valve?

[Harry S.]

Re: Need help restoring a 1963-66 STV valve for factory C60

Thanks Harry Then i know that i have to put a o ring there as well
In the STV valve restore kit i bought there is 1 small special washer that can not see where iy is supposed to be placed in any of the diagrams for the STV valve i have
Any here knows where this small washer in the picture below is supposed to be placed in the STV valve?

Take your replacement diaphragm and piston and place it on the table the same way it is in the picture you posted. Now look down the center of the hole, you will see that metal star like washer in the hole. It is holding a screen in place as I recall.

When you put in the new diaphragm you are to remove the old metal star like washer, it usually breaks. Then clean everything install the new diaphragm and put it back together.

[Claus S.]

Re: Need help restoring a 1963-66 STV valve for factory C60

Thanks again Harry Since i already have have a new diaphragm and piston that came mounted(together as one part)the star washer is already placed inside the piston

But i wold never have seen that if you have not told me

[Harry S.]

Re: Need help restoring a 1963-66 STV valve for factory C60

Claus, if you need to replace just the rubber part in the future, remove the star like washer first, then the screen then the rubber. It is much easier to install the rubber with everything out of the way as you need to pull the tit through the hole.