Curise control won't stop

[Billy]

The cruise control vacuum pump won't stop, I really can't crimp the line because it's looks and feels like hard plastic. Any ideas on how to locate the leak? Would soapy water do it? I can't picture bubbles forming when the line is sucking, what do ya'll think? Thanks.
I did a search on this site, no help.
2003 3500 5.9

 

[Prairie Dog]

No, the bubbles thing wont work and would just suck it up into the lines and pump.

 

[Bill Stockard]

The cruise control vacuum pump won't stop, I really can't crimp the line because it's looks and feels like hard plastic. Any ideas on how to locate the leak? Would soapy water do it? I can't picture bubbles forming when the line is sucking, what do ya'll think? Thanks.
I did a search on this site, no help.
2003 3500 5.9

Remove the rubber hose connector at the pump and block the inlet to the pump. If the pump cycles off, your problem is a leak in the line between the pump and the cruise control servo under the driver side battery or in the cruise control servo. If the pump continues to run with the inlet blocked, the pump is defective. Good luck!

Bill

 

[Ozymandias]

The Heater Doors are also vacuum activated. At least my Dual Zone has it that way.

 

[Bill Stockard]

The Heater Doors are also vacuum activated. At least my Dual Zone has it that way.

Beginning with the third generation trucks, the heater doors are operated by DC servo motors. Second generation trucks and prior heater doors were vacuum operated.

Bill

 

[Ozymandias]

Hm, i got a vacuum hose routed through the firewall right in the middle over the engine head cover.
Where goes this hose? I thought its for the heater doors.

 

[Bill Stockard]

Hm, i got a vacuum hose routed through the firewall right in the middle over the engine head cover.
Where goes this hose? I thought its for the heater doors.

According to my 2003 Factory Service Manual (FSM), the hose you see entering the cowl connects to a vacuum reservoir; however, the FSM further states that a vacuum reservoir is not used on diesel engine models. Evidently, if my FSM is correct, the line must be blocked off where it would normally connect to a vacuum reservoir.

Bill

 

[Ozymandias]

Well that enlightens me, thanks for this info. A line into nowhere..... Funny Truck. *Shake Head, grin, walks away*