Cruise Control Speed Servo Control Components

[puddlepirate]

Hello all, I've been lurking here for a while since we purchased an early 69 Mark III. The frame is in great condition, body in good condition, but it had been sitting in a concrete parking garage since 2007. My boys and I have a lot of work cut out for us. I've been able to find quite a bit of the information here that we need to get it back on the road, and I thank you all.

So now the question: Mounted on the firewall is the rear plate of the Speed Servo Assembly, with about 1/2" of rubber boot. The rest is gone. I haven't been able to find a further breakdown of the assembly. I see that bellows are available online, but that still leaves us without the end cap. Can I assume that the bellows are completely hollow, and machining an endcap to fit the end cable to attach to the throttle linkage is all we need?

[Lee]

If nobody else steps up, I believe Oldsmobile used the same basic setup, and it looks like this. The bellows may have a return spring inside.

[1Bad55Chevy]

That's how the stock assembly looks on the vehicle. I am not following what pieces you are looking for.

[puddlepirate]

Thank for you for the prompt response, it is very helpful. I suppose a picture definitely would have helped explain what I was trying to explain. A lot of internet results are coming up for Jaguar's similar part too. I'm wondering if it would not be too difficult to mount up one from another vehicle such as the Olds you mentioned.

Thanks again!!

[TonyC]

Chevy, your Mark still has the hydraulic wiper motor?? I thought that was completely ditched by '71. I knew that some '70 models still had it, but they were also phasing in an electric option that year. I didn't know they still offered both options in '71.

Sorry, not meant to hijack, but I just noticed that.

---Tony

[1Bad55Chevy]

Chevy, your Mark still has the hydraulic wiper motor?? I thought that was completely ditched by '71. I knew that some '70 models still had it, but they were also phasing in an electric option that year. I didn't know they still offered both options in '71.

Sorry, not meant to hijack, but I just noticed that.

---Tony

Where have you seen a reference to an electric wiper option on a Mark iii? I would love to replace that because I hate the hoses running up there. The driver's side of the engine bay looks HORRIBLE in a Mark iii because of the speed control box and the wiper lines! IMO the speedometer box looks like a a gray electrical box you buy at Lowes!

[Lee]

Well, isn’t THIS interesting…they must have had serious problems with the electric.

[TonyC]

Well, Lee found one reference. My info came from an owner's manual I had salvaged from an organ donor years ago, which gave operator's details on how to use either system. I can't remember what I did with it; I may have sold it to somebody who needed one. But Lee's example gets my interest now; if it was due to problems with Lincoln's first-ever electric wiper motors, I wonder if that issue extended to the then-new full-sizers of that year as well...?

Personally, I would say that if aesthetics is the only issue with the hydraulic system, keep it as it is. The hydraulic wipers operate much faster than any electric system I've ever seen. If it's otherwise operating properly, without leaks, there's no real reason other than "just-because" to change it out. But that is your call to make, not mine; at least the Mark III should be easier to convert than a clap-door.

---Tony

[LithiumCobalt]

There were plans to offer electric intermittent wipers. They either never made it to production or only very few were equipped as such. The option was canned due to a lawsuit or potential lawsuit. Someone claimed that it was patented already. Can’t remember the parties involved but I think there was a book or movie made about the ordeal. Cars that were originally going to be equipped with the electric wiper system had a page with the hydraulic wiper instructions glued over the electric operation instructions in the owners manual

[puddlepirate]

Well, I managed to find a NOS Jaguar bellows and endcap on ebay for about the price of the Mark III bellows by themselves. The seller measured the bellows to be about 3.5" which is about what I measured the one on the Mark III to be. Hopefully it works out. If not, I'll just attempt to recoup some of the money and shelve (for now) the idea of getting cruise control working.

Here's what I purchased: https://www.ebay.com/itm/395166905260