IPD sale XeMODeX - Experts in Volvo Electronics Free shipping all USA - Experts in Brakes
Did you know? 🤔
Logged in users can get email notification of topic replies Log in or register (free).
Amazon Link Buy your stuff using this and it helps MVS!

'96 855 T5 - Vacuum - does it matter where it comes from?

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

1992 - 1997 850, 850 R, 850 T5-R, 850 T5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

Sommerfeldt
Posts: 1113
Joined: Tue Jul 29, 2008 1:25 pm
Year and Model: 1996 850 T5
Location: Oslo Area, Norway
Has thanked: 50 times
Been thanked: 30 times
Norway
Sommerfeldt

'96 855 T5 - Vacuum - does it matter where it comes from?

Post by Sommerfeldt » Fri Jan 18, 2019 5:04 am

I'm moving some things around and trying to clean up my engine bay a little. A lot, in fact. I'm planning to move the battery to the back (it's already "sideways"), and getting an enclosed CAI that can utilize that space. I've installed a new catch can, but it's a right mess in these bays...

So, I'm thinking about getting a vacuum station, and have everything possible run from that. So the question... does it matter where the vacuum comes from? Can I run brake booster, boost gauge, FPR, turbo diaphragm and so on from that same station?
Obviously things like the TCV needs its specific connections to things, and also the vacuum from intake manifold to intake tube, but is there any reason everything else couldn't pick up from the same place?

- S
'96 855 T5, R bumper and spoiler, Koni Yellows & blue H&R springs all 'round.

User avatar
abscate
MVS Moderator
Posts: 19959
Joined: Sun Feb 17, 2013 5:54 pm
Year and Model: 99T5 ,99S70,2005V70
Location: NYC, ALBANY NY
Has thanked: 266 times
Been thanked: 846 times
Trinidad & Tobago
abscate

Re: '96 855 T5 - Vacuum - does it matter where it comes from?

Post by abscate » Fri Jan 18, 2019 5:12 am

I think the FPR and turbo vacuum have to come from specific places. The rest won't matter too much.

That's an educated (?) guess
These users thanked the author abscate for the post:
Sommerfeldt
Empty Nester
A Captain in a Sea of Estrogen
1999-V70-T5M56 2005-V70-M56 1999-S70 VW T4 BMW
Link to Maintenance record thread
Link To Volvo Glossary

Sommerfeldt
Posts: 1113
Joined: Tue Jul 29, 2008 1:25 pm
Year and Model: 1996 850 T5
Location: Oslo Area, Norway
Has thanked: 50 times
Been thanked: 30 times
Norway
Sommerfeldt

Re: '96 855 T5 - Vacuum - does it matter where it comes from?

Post by Sommerfeldt » Fri Jan 18, 2019 5:31 am

Well, the FPR isn't making much of a mess anyway, so that's fine, I guess. :D
The recirc valve on the turbo is picking up from the front of the engine, above the big port for the brake booster, so I'm guessing that can be moved?

- S
'96 855 T5, R bumper and spoiler, Koni Yellows & blue H&R springs all 'round.

Ozark Lee
MVS Moderator
Posts: 14798
Joined: Thu Sep 07, 2006 8:24 am
Year and Model: Many Volvos
Location: USA Midwest
Has thanked: 4 times
Been thanked: 49 times
United States of America
Ozark Lee

Re: '96 855 T5 - Vacuum - does it matter where it comes from?

Post by Ozark Lee » Fri Jan 18, 2019 6:18 am

Engine vacuum is not a constant. It is very different at idle when compared to cruising speed or WOT and many functions, particularly the boost control, are tied to the vacuum level. The power brakes don't much care where it comes from and the booster is like a big vacuum "capacitor" that tries to maintain a vacuum level no matter the driving condition. Throttle position has largely changed the engine performance tuning that used to be vacuum controlled but there are still some functions that actually need it,

If you go back in the "wayback" machine some of the early implementations of windshield wipers were run off of manifold vacuum and they had the neat feature that they would stop working when you floored the car. Worked great at the stop light though.

...Lee
These users thanked the author Ozark Lee for the post:
Sommerfeldt
'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

Post Reply
  • Similar Topics
    Replies
    Views
    Last post