1998 S70 Trivia: Can you identify this small tube?

BrianD · Post by **BrianD** » 11 Feb 2014, 18:16

The narrow plastic tube pictured below wound up in my dad's hand when we were scrambling to jump the 1998 S70 (base model). He says it had rubber fittings on at least one end that had disintegrated. I have no idea what it is, or if it is important.

It's about 15" long, and the outer diameter is maybe a little less that 1/8". I wish I could be more specific about where it came from, but all I know for sure is that was on the driver's (left) side, under the hood, near the top of the engine. I think it was somewhere between the head and the firewall, but can't be certain.

This is my first Volvo and I'm not the best home mechanic. The existing threads here have been a godsend since the S70 entered my life. I hope one (some?) of you brilliant folks will recognize it and help me keep the car running in top shape. I wish I had a prize to offer! But bonus points if you can also tell me how important it is (or isn't).

Cheers,

Brian

(edit: changed linked file to attachment)

Post by **JRL** » 11 Feb 2014, 18:29

It's a vacuum tube and should be important
Where it came from is anyone's (good) guess

Post by **cn90** » 11 Feb 2014, 18:48

Probably cruise control.

Post by **abscate** » 11 Feb 2014, 19:04

Could be evap purge hose. Look for a valve under the plastic lid on the driver died near the radiator

Make sure you have two hoses running to that valve

Post by **erikv11** » 11 Feb 2014, 19:05

Cruise control vacuum lines are buried under the battery tray, tucked safely away, that's not going to be it.

Could be an SAS vacuum line. Keep an eye out for a check engine light and an EVAP code.

A pic of the top of the engine would help, especially if it shows well that area above the head and to the firewall (so that we can see if there is an SAS valve on this vehiclel).

Post by **rspi** » 11 Feb 2014, 20:01

Does that tube go from the back of the air box to the vac tree?

Post by **xHeart** » 11 Feb 2014, 20:30

More here https://www.matthewsvolvosite.com/forums/viewtopic.php?t=49490&p=245663

Post by **erikv11** » 11 Feb 2014, 20:48

rspi wrote:Does that tube go from the back of the air box to the vac tree?

ooooh, good guess. My money's on that one.

Post by **Rondo** » 11 Feb 2014, 21:26

If the line is that small, could it be the windshield washer tube that connects the two nozzles under the hood? Does that sound dumb? I know mine broke a few years ago and I found it on top of the spark plug cover.

BrianD · Post by **BrianD** » 12 Feb 2014, 12:34

Ding ding ding! Great team work, thanks.

It is the same line diagnosed in the post linked to above by xHeart, and suggested by others:
https://www.matthewsvolvosite.com/forums ... 0&p=245663
I should have been more thorough in searching past threads.

Both ends connect to the air filter box. One along the firewall-side, near the top, and the other on the front bottom corner, on the passenger (right) side. I gather this second connection is the "vacuum tree." In that spot I found a busted elbow connector, but the connector at the other end is just missing.

I think I have enough info to get the parts and fix it, but if anyone has any pointers or other thoughts, they'd be more than welcome!

Thanks,

Brian