Cruise control fails to cancel - The 1947 - Present Chevrolet & GMC Truck Message Board Network

75C10 · 08-04-2018, 10:23 PM

My cruise (non resume early factory 77ish) worked fine for about two hours on the highway. Then upon application of the brake it seemed to cancel but lifting the brake, the cruise reapplied by itself. Something prevented the cruise to cancel. Pushing the on/off switch (deep push to position 2) also shut off the cruise but the switch had to be held in. What's wrong?

75C10 · 08-06-2018, 12:52 AM

So I drove the same 300 km today and at first the cruise worked fine, then it wouldn't disengage without the indicator button being pushed but by the time I arrived at home it was disengaging from the brake pedal as it should. The Cruise transducer has a foamy in its base to filter air that moves through the unit so maybe they can get dirty? Anybody have a clue as to servicing the transducer. The web seems pretty thin on this info. Anybody take one of these apart???

**hatzie** · 08-06-2018, 07:32 AM

There used to be a PDF writeup on a UK college student web page but it doesn't seem to exist anymore. If anyone has it a copy for the manuals page would be appreciated.
The Cruisemaster Service Training Textbook I scanned is in my manuals post.

75C10 · 08-06-2018, 12:41 PM

I appreciate you posting these manuals and thank you for it. However, the cruisemaster manual doesn't have an in depth trouble shooting section. I have been reluctant to buy a rebuild transducer but I will try and find one. I need to find a suitable candidate for an experimental disassembly.

chengny · 08-06-2018, 02:36 PM

From the 77 service manual:

chengny · 08-06-2018, 02:37 PM

And this:

**hatzie** · 08-06-2018, 11:36 PM

The 79 manual has a very good troubleshooting section too.
IIRC at least one of the 68-72 manuals has a fairly serious section on the Cruisemaster system as well... 67 pre-dates cruise control in the trucks.

75C10 · 08-07-2018, 06:14 PM

I appreciate your help and thank you. Today my cruise worked fine. Go figure. I am planning a big trek to Sacramento in Sept to the C10 club inaugral Intervention. Its 2200 km each way and cruise has to work. I researched the local auto parts stores and searched the internet and I cannot find a rebuilt unit. There just not available in Canada and perhaps scarce in the US. I may call O'Reillys (or somebody) and maybe I can pick up a unit in Spokane on my way through. For the moment mine works and disengages okay. Perhaps the dirt that was contained within it has been sucked out by vacuum and it may operate for awhile.

08-04-2018, 10:23 PM	#1
75C10 Registered User Join Date: Oct 2014 Location: Calgary Alberta Posts: 161	Cruise control fails to cancel My cruise (non resume early factory 77ish) worked fine for about two hours on the highway. Then upon application of the brake it seemed to cancel but lifting the brake, the cruise reapplied by itself. Something prevented the cruise to cancel. Pushing the on/off switch (deep push to position 2) also shut off the cruise but the switch had to be held in. What's wrong?

08-06-2018, 12:52 AM	#2
75C10 Registered User Join Date: Oct 2014 Location: Calgary Alberta Posts: 161	Re: Cruise control fails to cancel So I drove the same 300 km today and at first the cruise worked fine, then it wouldn't disengage without the indicator button being pushed but by the time I arrived at home it was disengaging from the brake pedal as it should. The Cruise transducer has a foamy in its base to filter air that moves through the unit so maybe they can get dirty? Anybody have a clue as to servicing the transducer. The web seems pretty thin on this info. Anybody take one of these apart???

08-06-2018, 07:32 AM	#3
hatzie Moderator Join Date: Oct 2008 Location: Wentworth, NH Posts: 4,977	Re: Cruise control fails to cancel There used to be a PDF writeup on a UK college student web page but it doesn't seem to exist anymore. If anyone has it a copy for the manuals page would be appreciated. The Cruisemaster Service Training Textbook I scanned is in my manuals post. __________________ 1959 M35A2 LDT465-1D SOLD 1967 Dodge W200 B383, NP420/NP201 SOLD 1969 Dodge Polara 500 B383, A833 SOLD 1972 Ford F250 FE390, NP435/NP205 SOLD 1976 Chevy K20, 6.5L, NV4500/NP208 SOLD 1986 M1008 CUCV SOLD 2000 GMC C2500, TD6.5L, NV4500 2005 Chevy Silverado LS 2500HD 6.0L 4L80E/NP263 2009 Impala SS LS4 V8 RTFM... GM Parts Books, GM Schematics, GM service manuals, and GM training materials... 1973-1991 GM Light Truck Service, Unit/Overhaul, Wiring Manuals, Parts Books and Some 1968-1999 GM Service Training textbooks in PDF 1988-1998 GMT400 CK service manual project 1988-1993 GMT400 CK parts books. 1967-1972 GM Light, Medium, & Heavy Truck Service Manuals in PDF Please include at least the year and model in your threads. It'll be easier to answer your questions. And please let us know if and how your repairs were successful.

08-06-2018, 12:41 PM	#4
75C10 Registered User Join Date: Oct 2014 Location: Calgary Alberta Posts: 161	Re: Cruise control fails to cancel I appreciate you posting these manuals and thank you for it. However, the cruisemaster manual doesn't have an in depth trouble shooting section. I have been reluctant to buy a rebuild transducer but I will try and find one. I need to find a suitable candidate for an experimental disassembly.

08-06-2018, 02:36 PM	#5
chengny Registered User Join Date: May 2007 Location: New Hampshire Posts: 349	Re: Cruise control fails to cancel From the 77 service manual: Attached Images

08-06-2018, 02:37 PM	#6
chengny Registered User Join Date: May 2007 Location: New Hampshire Posts: 349	Re: Cruise control fails to cancel And this: Attached Images

08-06-2018, 11:36 PM	#7
hatzie Moderator Join Date: Oct 2008 Location: Wentworth, NH Posts: 4,977	Re: Cruise control fails to cancel The 79 manual has a very good troubleshooting section too. IIRC at least one of the 68-72 manuals has a fairly serious section on the Cruisemaster system as well... 67 pre-dates cruise control in the trucks. __________________ 1959 M35A2 LDT465-1D SOLD 1967 Dodge W200 B383, NP420/NP201 SOLD 1969 Dodge Polara 500 B383, A833 SOLD 1972 Ford F250 FE390, NP435/NP205 SOLD 1976 Chevy K20, 6.5L, NV4500/NP208 SOLD 1986 M1008 CUCV SOLD 2000 GMC C2500, TD6.5L, NV4500 2005 Chevy Silverado LS 2500HD 6.0L 4L80E/NP263 2009 Impala SS LS4 V8 RTFM... GM Parts Books, GM Schematics, GM service manuals, and GM training materials... 1973-1991 GM Light Truck Service, Unit/Overhaul, Wiring Manuals, Parts Books and Some 1968-1999 GM Service Training textbooks in PDF 1988-1998 GMT400 CK service manual project 1988-1993 GMT400 CK parts books. 1967-1972 GM Light, Medium, & Heavy Truck Service Manuals in PDF Please include at least the year and model in your threads. It'll be easier to answer your questions. And please let us know if and how your repairs were successful.

08-07-2018, 06:14 PM	#8
75C10 Registered User Join Date: Oct 2014 Location: Calgary Alberta Posts: 161	Re: Cruise control fails to cancel I appreciate your help and thank you. Today my cruise worked fine. Go figure. I am planning a big trek to Sacramento in Sept to the C10 club inaugral Intervention. Its 2200 km each way and cruise has to work. I researched the local auto parts stores and searched the internet and I cannot find a rebuilt unit. There just not available in Canada and perhaps scarce in the US. I may call O'Reillys (or somebody) and maybe I can pick up a unit in Spokane on my way through. For the moment mine works and disengages okay. Perhaps the dirt that was contained within it has been sucked out by vacuum and it may operate for awhile.



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