Cruise Control Unit Rebuild

[Mheiron]

So I was curious if anyone has had any experience getting an original cruise control unit to work or if it was worth it to try.
The current unit appears to have been disconnected from the carb and the vacuum line was removed but otherwise appears to be complete. The wiring harness is still in the car and the turn signal stalk has the activator but I donkt know yet what the brake light switch should look like. The speedometer cable still goes through the cruise control unit.
Does anyone know anybody that rebuilds these units? I’ve checked out a spare unit from eBay and it has a geared clock like mechanism .
I spoke with Julius of “Restorations by…” and he said he’s never seen one work and they were not worth fooling with.
But I love a challenge!
Appreciate the thoughts of all you wisemen. Thanks in advance.

 

[pnora]

Get the FSM and read up on it. Then get yours hooked up and see what it does.

 

[493 Mike]

I was a line mechanic when those came out. Pretty simple and I never had one fail.
Mike

 

[shanker]

I have collected 6 of them now trying to find a working one. ALL of the ones I have suffered a failure due to a dry rotted & cracked diaphragm. If you open one up you'll see what I'm talking about. They were never a serviceable part and were replaced. I'm tempted to use some flexible bike tube patches and liquid electrical tape to try and get one of mine to hold a vacuum and see what happens.

My wife's 75 Duster 360 and 74 Ramcharger SE both left the assembly line with cruise control.

 

[Tony Tee]

I made a mold to reproduce the diaphragms a few years back but it seems nobody was interested. So I have a supply for myself . Made them out of silicone. I haven't tested them, as my car isn't finished yet.

 

[gtx6970]

Ive taken a few different non working servos apart over the years ,,, and ALL of them had split diaphragms

PS, the 69 and earlier servo is near impossible to find

 

[1 Wild R/T]

Ive taken a few different non working servos apart over the years ,,, and ALL of them had split diaphragms

PS, the 69 and earlier servo is near impossible to find

Yup, every listing shows 68-74 but 68-69 is different...
@Tony Tee first time I've seen those.... If you don't get the word out they won't sell...

 

[Darter6]

. If you don't get the word out they won't sell...

Mine is not working.Now I know what to look for. Thanks all !

 

[YY1]

I thought I read on a recent post that some did not use a diaphragm.

Was I mistaken? If correct, those would be the ones to find.

...but that replacement mold is AWESOME.

How much were you asking?

I intend to add one to my 73 and have about 80% of the parts.
Haven't looked inside the can, though.

 

[Tony Tee]

I thought I read on a recent post that some did not use a diaphragm.

Was I mistaken? If correct, those would be the ones to find.

...but that replacement mold is AWESOME.

How much were you asking?

I intend to add one to my 73 and have about 80% of the parts.
Haven't looked inside the can, though.

Honestly I have no clue if these will work being made out of silicone. They fit perfect and silicone is heat resistant. But they have not been tested in a car. And if they work? longevity is a question. Plus they are not easy to make without any bubbles or voids being as thin as they are. The material is injected while in a vacuum chamber. Not easy. And then it's not finished. the rivit on your old diaphragm has to be drilled out and the paper and metal disc's re fastened to complete the assembly. I'll post more pictures when I get the chance.

 

[YY1]

My wife molds and casts in silicone.

We have a pressure pot and a vacuum chamber pot.

.....and she bought the vacuum pump that I've used twice to work on my car's AC.

 

[shanker]

Tony Tee....what you did there is AMAZING! There are some folks over on FABO who are wanting to repair their units as well.It's time to test your prototype(s) !!!!

 

[YY1]

FWIW- I put a silicone trans pan gasket on my 904.

Seals perfect. Much better than a stock gasket.

...and it's been exposed to transmission fluid for almost 10 years.

 

[Tony Tee]

FWIW- I put a silicone trans pan gasket on my 904.

Seals perfect. Much better than a stock gasket.

...and it's been exposed to transmission fluid for almost 10 years.

Thanks, I use the good platinum based silicone. My worries are that I tint the blue silicone with black pigment which makes it grey. if I add more tint it to make it darker (oem black) it weakens the silicone otherwise the diaphragms will be sky blue in color but will be stronger. My other worry is, it might be too stretchy and not pull the throttle cable under vacuum. I have no clue what the oem diaphragms are made from but the old ones are not stretchy just flexible and now old and brittle.
Before I built this mold, I tried vacuum forming diaphragms of many different materials with no good results. There seems to be more interest in these now. So I'll have make some time and clean off my bench and run some more.

 

[YY1]

Can you see the color from outside the unit?

Just me, but I'd gladly trade a color that's not OE, which you can't see, for strength.

FYI my transmission gasket is red.

You can only see it if you are on the same plane and look read hard, with a light.

 

[Rockland71GTX]

I wouldn't give a crap if it was hot pink as long as it works! The only place you'd see it is at the edge and you can color that with a sharpie.

 

[Tony Tee]

I did color one blue one with a sharpie around the edges. It looked ok.

I wouldn't give a crap if it was hot pink as long as it works! The only place you'd see it is at the edge and you can color that with a sharpie.

 

[1 Wild R/T]

If you decide to go forward offer them it blue or black.... Get a few extra $$ from the guy who needs black.... Cool that your able to make them, get them tested & make a few $$$ for your efforts.... I'm lucky, I picked up a few NOS servos back when they were still popping up on Ebay and no one was looking for them.... I used three on my cars, all three still work & I have a spare on the shelf....

 

[Tony Tee]

I just saw a nos servo on ebay for just shy of $500

If you decide to go forward offer them it blue or black.... Get a few extra $$ from the guy who needs black.... Cool that your able to make them, get them tested & make a few $$$ for your efforts.... I'm lucky, I picked up a few NOS servos back when they were still popping up on Ebay and no one was looking for them.... I used three on my cars, all three still work & I have a spare on the

 

[1 Wild R/T]

I just saw a nos servo on ebay for just shy of $500

LOL.. I picked up all four of mine for about 30% of that... The best one was an NOS dealer add-on kit so it had an NOS brake switch, wiring harness, both speedo cables, lots of throttle brackets, an NOS T/S lever/CC switch but the type used starting in 74.... All of it, the whole kit, no other bidders, nobody wanted it... I got it for $35.....