85_Ranger4x4
Wallows in rivers
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- Joined
- Aug 7, 2007
- Messages
- 35,321
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- 2,001
- City
- Frankfort
- State - Country
- IA- USA
- Vehicle Year
- 1985
- Engine
- 5.0
- Transmission
- Manual
For the most part mine works great, sometimes it surges though. On our trip to Ohio it seemed impact related, hit a big bump and surgy surgy until I pulled the vacuum line off the servo. One time I hit a big bump and it got to surging and then I hit another railroad crossing and it came out of it. It only did it thru Illinois on the way out (they have a crappy highway), across Iowa, Indiana and Ohio and then the whole way home it didn't miss a beat. It did it again after it sat all winter... until I pulled the vacuum line off the servo and it has worked perfect for two days now.
Vacuum reservoir and lines were new last fall, I have tried two different amplifiers (one for a 2.8 BII and one for a 5.0 F-150, it hisses when I pull the vacuum line off (engine not running) so the checkvalve and dump valve are holding... so I did some digging and found this:
www.fordforums.com
Kinda makes sense, the valves are gummed up and stick if it gets bumped the wrong way. Since it works most of the time I wondered how hard it is to clean and lube the valves in what I have... I have a kind of crusty looking spare so I did an exploratory on it... and I don't see much and the two motor looking things don't want to come out:

How the system works:

Electronically the servo tests fine as per the EVTM, Ford shop manual and a neat thing I found here. The thread about fixing your servo looks like it might be in some other country (Australia maybe?) so they might have something different than what I have. I could keep grabbing them out of the JY hoping for something better or snag a NOS that might be a few years newer than what I have or get a $100 rebuilt one from who knows where... nothing really appealing and there is no actual valve test in any of the Ford literature I have found.
Has anybody else delved down this rathole?
@19Walt93
Vacuum reservoir and lines were new last fall, I have tried two different amplifiers (one for a 2.8 BII and one for a 5.0 F-150, it hisses when I pull the vacuum line off (engine not running) so the checkvalve and dump valve are holding... so I did some digging and found this:

Cruise Control Surging
Does anybody know why my cruise control surges sometimes and not other times? Say I turn the cruise on at 100kph, the speed may drop to 98 then accelerate up to 102 and continue to cycle like that (on a totally flat road). Other times it works fine and hold the speed completely constant. Car is...
Kinda makes sense, the valves are gummed up and stick if it gets bumped the wrong way. Since it works most of the time I wondered how hard it is to clean and lube the valves in what I have... I have a kind of crusty looking spare so I did an exploratory on it... and I don't see much and the two motor looking things don't want to come out:

How the system works:

Electronically the servo tests fine as per the EVTM, Ford shop manual and a neat thing I found here. The thread about fixing your servo looks like it might be in some other country (Australia maybe?) so they might have something different than what I have. I could keep grabbing them out of the JY hoping for something better or snag a NOS that might be a few years newer than what I have or get a $100 rebuilt one from who knows where... nothing really appealing and there is no actual valve test in any of the Ford literature I have found.
Has anybody else delved down this rathole?
@19Walt93
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