DIY: 1998 S70 GLT Documenting Vacuum Hoses [Turbo]

[cn90]

DIY: Documenting Vacuum Hoses

I just want to dedicate a thread strictly to photographing the vacuum lines in these aging Volvos.

As the car gets older, vacuum hoses break and people are always asking for diagram. The problem with underhood sticker is that: it looks good on paper but it has its limitation, i.e., no real photos.

I just spent 1h photographing different vacuum lines of my 1998 Volvo S70 GLT.

If you have other photos, please annotate them with arrows/caption etc. and post them (especially those with blue silicone hoses lol…).

>>> Looking for non-turbo vacuum hose diagrams? <<<

Please state your year model when posting photos, this way people know which car it came from!

The best way to handle this project is to get an assorted mixture of vacuum hoses at local parts store. I don’t remember the exact size of each hose, but since these vacuum hoses are so cheap (a few dollars for 6 feet), just get different sizes b/c you will need it later for something else. Just drive the car there and the people at the parts store will help you get the correct sizes.


1. General Photo of my 1998 Volvo S70 GLT:

Volvo-Vacuum-01.JPG (221.84 KiB) Viewed 28863 times

2. This hose I lable #3 is tricky, it connects to port #3 in I.M. to this location at the Turbo:

Volvo-Vacuum-02.JPG (123.7 KiB) Viewed 28863 times

3. This hose goes to FPR, it connects to the small metal pipe behind the engine. Please see this excellent DIY by jreed:
https://www.matthewsvolvosite.com/forums ... hp?t=54895

Volvo-Vacuum-03.JPG (108.89 KiB) Viewed 28863 times

4. This solenoid has a T-connector: 1 end goes to Rubber Boot (arrow), the other end goes to Turbo (dots + arrows):

Volvo-Vacuum-04.JPG (119.35 KiB) Viewed 28863 times

5. SAS system. I shows the photo here but I already did the “SAS Delete” using the 99-cent Radio Shack diode:

Volvo-Vacuum-05.JPG (109.13 KiB) Viewed 28863 times

6. This T-connector provides vacuum to:
- EVAP Solenoid
- The port near the PTC Valve (Yellow Arrow)

Volvo-Vacuum-06.JPG (140.87 KiB) Viewed 28863 times

7. The vacuum hose starts at the (R) side of the I.M. ---> PTC nipple. Please the PCV DIY by jblackburn and cn90:

https://www.matthewsvolvosite.com/forums ... hp?t=28487

https://www.matthewsvolvosite.com/forums ... hp?t=53448

Volvo-Vacuum-07.JPG (116.9 KiB) Viewed 28863 times

That is all for now, anyone with more photos, please add to the collection to help others keep the old beasts going…

[cn90]

For reference purpose, this excellent thread has some diagrams:

https://www.matthewsvolvosite.com/forums ... php?t=6941

[RumpusRoom]

This is great!

[cn90]

Another vacuum hose I forgot to mention is the hose from the solenoid ---> bottom of turbo (YELLOW arrow).

This hose is difficult to get to from below but with some patience (and long needle-nose pliers), you should be able to do it:

VolvoTurboHose.JPG (87.75 KiB) Viewed 28837 times

[deepsouth]

This is great information. But I'm not sure where this hose goes. It leaves the manifold, runs under the throttle body, under the air box (where mine is joined by a plastic connector) and then heads under the fuse box towards the booster. It very rotten. Any ideas?
Eric

[cn90]

@deepsouth,

I think it is for Brake Booster.

http://volvospeed.com/vs_forum/topic/51 ... e-booster/

I borrowed the photo from crazykn and repost them here:

DSCN1483Medium.jpg (84.06 KiB) Viewed 28823 times

DSCN1484Medium.jpg (53.94 KiB) Viewed 28823 times

[deepsouth]

I think it is for Brake Booster.

Yup. That's it! That was my hunch but the other end is a real PITA to see, let alone get to. Perhaps the reason for the plastic connector?
Eric

[erikv11]

FYI, here is a post with similar info for non-turbo versions:

https://www.matthewsvolvosite.com/forums ... =1&t=65002

[mecheng]

Another vacuum hose I forgot to mention is the hose from the solenoid ---> bottom of turbo (YELLOW arrow).

This hose is difficult to get to from below but with some patience (and long needle-nose pliers), you should be able to do it:

VolvoTurboHose.JPG

I noticed this hose (solenoid to turbo) when I was replacing the turbo coolant lines is soaked in oil. Should I change it or if it was leaking it would throw a code correct?

[erikv11]

If torn yes, but if the line is spongy and leaky but not torn, then it will not necessarily throw a code. Boost control may be a little sluggish, though.

Generally speaking, it is much more efficient to just get in there and replace all of the lines. The rubber is coming up on 20 years old, even if the engine bay was kept clean it may be getting crumbly just from drying out etc.