Diagnosing an EVAP leak on motronic 4.4

[SwampRat5605]

Can anyone confirm what hose size to get for the Blue (#1) and Red (#2) hoses listed in the attachment? I'm getting ready to replace all my vacuum hoses with silicone and I'd love to know exactly which hoses to get. I looked at the link posted by cn90, but I couldn't find a definite answer. I'm thinking the blue hose is either 6 mm or 8 mm, and the red hose is either 8 mm or 10 mm. Thanks in advance.

[cn90]

I have a practical advice re vacuum hoses...

Keep a variety of vacuum hoses at home, they are cheap, about $3 for each pack.
So get 6-mm, 7-mm, 8-mm, 9-mm, 10-mm packs.
They should be good for vacuum lines, windshield washer etc. etc.
This way you don't waste time/energy/gasoline running back and forth to the local auto parts store.

[SwampRat5605]

The reason I ask is because is because the blue hose (#1) in the attachment is by far the longest vacuum hose I want to replace. So when I purchase 10-15 feet for this hose, I want to make sure its the right size.

I do like your advice about keeping a variety of vacuum hose sizes around. BTW, which auto store did you purchase hoses from?

[cn90]

Follow-up 3 months later:

1. Replaced cracked hose as mentioned above.
Code P0440 came back!

2. Got new gas cap at Advance Autoparts for $8.00.

3. Cleaned the Bosch Purge Valve with brake cleaner, it worked for 1 week, code P0440 kept coming back!

Removed the Purge Valve 3 months later, it remained open (should have been closed when not activated), so I gave up.
Bought a brand-new Purge Valve on ebay for $40: PN 0 280 142 300, it is now made in China.
Code P0440 is gone for good!

So in my experience:
- Replace any cracked hoses, this is cheap to do.
- Replace gas cap, $8.00.
- Clean the Purge Valve but eventually you will need a new Pure Valve, at $40, it is not that bad of a price:

VolvoEVAPValve2.JPG (65.18 KiB) Viewed 2178 times

[SwampRat5605]

I just replaced all my vacuum hoses this weekend with silicone hoses (http://www.siliconeintakes.com/index.ph ... 73e1f9c024). Here is what I learned. Hose #1 is 6 mm. Hose #2 is 8 mm. A 4 mm hose works for the smallest vacuum hoses (like the ones on the back of the air filter). If you use silicone, you can eliminate all elbow hoses, with the exception of the elbows on the top of the charcoal canister. If you are replacing all your vacuum hoses, I suggest the following amounts:

4 mm - 8 ft
6 mm - 20 ft
8 mm - 3 ft

I would also suggest replacing the vacuum elbows of the top of the charcoal canister with new OEM parts. If you do this, you will also need two 1/4" hose connectors (they have plastic ones at Lowes/Home Depot) to connect the elbows to the silicone hose. Additionally, I recommend replacing the filter as well.

[xHeart]

- For the roll-over valve hose:
* No need to remove the bracket.
* Use a pair of needle-nose pliers to TWIST the hose to undo the bond between the hose and its connections. Then remove it.
* I happened to have standard 1/4" heater hose laying around. It fits the "roll-over" valve nipple perfectly, but is a tad too small form the other end. No problem, simply enlarge the other hose's end a bit using a pair of needle-nose pliers.
* Add one drop of oil to each end to ease insertion.

I am working on EVAP. The purge valve is replaced.
I will replace the two 4" section of hose on either end of the roll-over value near the fuel filter.

Does 1/4" hose in the picture needs a clamp, since it is not a volvo part?
I will stretch one end, as cn90 suggests above, for it to slide over the larger diameter plastic line.

replacement parts...

MVS_0838.jpg (280.82 KiB) Viewed 1975 times

[erikv11]

I've done this on several 850s now, always used generic fuel hose and clamps.

[xHeart]

I've done this on several 850s now, always used generic fuel hose and clamps.

Thank you!.
Replaced the two 4" connecting rubber hoses at the either end of roll-over valve. The word Vent is embossed on it. Old hoses broke into pieces.

The hose section directly above the fuel filter requires the valve bracket be removed. It is safer then to pull off old and insert the new on to the line.

I may have defeated P0455, will confirm later.

[xHeart]

...and YES!
There is no recurrence, passed 100 miles since the fix.
I am living without the notorious P0455.
Happy Spring.

[xtrattitude4u]

Since this repair, I've been CEL free.
Well, except for (no speedometer signal) driving to school without my ABS module while it was drying.
But that doesn't count, right?
I'm glad to see this thread helping people. Those EVAP codes are evil.