76 CDV cruise control chain question

[jeff elliott CLC #23590]

Hi,

could anyone tell me what the tension (or play) should be on the cruise control chain between the  carb throttle and the servo (power unit).?

regards Jeff.

["Cadillac Kid" Greg Surfas 15364]

Jeff,
I don't know what the manual says, or if it even has a "setting" , but the chain should be just barely slack when the throttle is fully closed and of course, the cruise control is not energized.  Too much slack will result in both "hunting " and less than full throttle action.
Greg

[jeff elliott CLC #23590]

Hi Greg,

thanks for quick reply, the cruise control on my car has never worked correctly (I imported the car abour 4 year ago from Colorado) it does tend to hunt or pulse, the chain is very slack and there is no mention of adjoustment in the workshop manual. so it looks like a good starting point to sorting out the problem (and at no cost).

best regards Jeff

[joecaristo]

I have an 77 Eldorado with cruise and it always surged and slowed down when the cruise was activated. It now finally works. The problem turned out to be the cruise control module. It looks like a red box inside the dash on the left hand side.
Joe

[TJ Hopland]

Just be sure that the chain is well locked into its clip after you adjust it.   Use a zip tie to be sure.  Had the one on my 73 adjust it self tighten one time.  Came off a freeway ramp doing a brake stand with the front tires smoking till I could get to a place to shut it off.

For the surging start out with a hand held vacuum pump and gauge and check things like the brake pedal release valve and other hoses and such.  At this age chances are good there is a cracked hose somewhere causing a leak so you just dont have a good strong vacuum signal. 

[mgbeda]

They must have changed the system in '77.  The '76s were completely mechanical and everything was under the hood, near the firewall, except the switch and set button.

-mB

[jeff elliott CLC #23590]

Hi,

I will adjoust chain tomorrow (day off work, due to royal wedding, why waste time watching TV) and see if it improves things. the system is mechanical the transducer etc. is on the firewall so changes would appear to have been made in 77.

to change the subject a little bit, I bought the car from a dealer in Sunny Parker CO which I believe is about 50 miles from you Mike, which is not a great distance in American terms I guess.

regards  Jeff

[TJ Hopland]

I thought the change was 78 but it may have depended on the body style.  I imagine the Seville got to try all the new tech stuff at that time then it worked onto the other models. I know around there somewhere they went from the under the hood in the cable sensor to a electronic sensor in the dash speedo head that talked to a module under the dash that then operated the vacuum servo on the engine. 

["Cadillac Kid" Greg Surfas 15364]

Jeff,
After you adjust the chain, go out and use the cruise control for a while.  They are mechanical devices and after not being used for extended time will frequently need to be used to work correctly.  There is a good section of the service manual about them and if you are carefull they are not hard to disassemble and clean.  The transducers which is essentially the only "working" device are still available.
Greg