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97 Volvo850 Sluggish cruise control

Help, Advice and DIY Tutorials on Volvo's P80 platform cars -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, including 850 R, 850 T-5R, 850 T-5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

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wlutz
Posts: 21
Joined: 9 April 2015
Year and Model: 1997 850 GLT
Location: Oregon

97 Volvo850 Sluggish cruise control

Post by wlutz »

I removed and repaired several damper motors on the climate control system...heating and cooling works correctly now thanks to the help received here. In the process I temporarily disconnected the cruise control bellows to gain access to a damper motor. After reconnecting the cruise control it now operates sluggish...going up a hill the speed drops significantly where before it held its speed...on level or small inclines it does fine. When first engaging cruise control it does not immediately lock in...it slowly responds so my speed is lower than wha I intended. Any suggestions? Thanks, wlutz.

Ozark Lee
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Post by Ozark Lee »

Make sure the vacuum line to the bellows isn't cracked, pinched, or otherwise pulled off the bellows. Whatever the leak is it is small or the cruise wouldn't work at all. Unfortunately, the really small leaks are the hard ones to find. Also make sure the mount was properly replaced. As I recall it isn't real obvious how the mount works and it is possible to get it replaced incorrectly.

The cruise vacuum line is a hard plastic line for most of its routing through under the hood from the vacuum pump and I'm not real sure where it transitions to a flexible line. The hard line has historically been trouble after many years of high temperatures from the engine but since the last place the system was moved was in the cabin that is where I would start.

...Lee
'94 850 N/A 5 speed
'96 Platinum Edition Turbo
Previous:
1999 V70XC - Nautic Blue - Totaled while parked.
1999 V70XC - RIP - Wrecked Parts Car.
1998 S70 T5
1996 850 N/A
1989 740 GLT
1986 740 GLT
1972 142 Grand Luxe

wlutz
Posts: 21
Joined: 9 April 2015
Year and Model: 1997 850 GLT
Location: Oregon

Post by wlutz »

I had only partially disconnected the 'mount'...right where it attaches to the climate system shell with a single screw...just enough to provide some working room. So I will pursue the vacuum leak possibility first. Thanks for the help. Wlutz

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