Return of the dreaded P0-455 GROSS EVAP Leak

Post by **sleddriver** » 13 Aug 2017, 15:56

EEEEEK.....GROSS....just when I thought I'd slain this dragon a few years back, she rears her ugly head once again. The gas cap is OEM Volvo with their nice seal. About one year old. I've cleared the code only to have it return...several times.

Off-the-top-of-my-head-what-hasn't-been-replaced: Gas tank top plumbing, fuel pump seal, fuel sender seal, J-hose on CharCan, big hose between tank and CharCan (vent hose?). PURGE & SHUT-OFF valves are relatively new (~6yrs).

I've never dropped the tank. The other day I had a thought though about using a truck inner tube to support the tank, then slowly letting the air out to lower it. Then the reverse to raise & support while hooking it all back up.

Her evil twin ABS is also back on for good. Not sure if it's the module (again) or the harness connector that's loose. Both systems have been a RPITA. I can't even remember when ABS has engaged. Haven't felt the brake pedal vibrate in a very long time. It used to do that on occasion when pulling out of the driveway for some odd reason. Testing?

Once more into the breech......

Post by **kahl** » 13 Aug 2017, 17:17

Before you drop the tank have the system smoke tested. Disconnect the evap hose behind the right front frame rail then smoke the front part of the system then the back.

Post by **erikv11** » 13 Aug 2017, 18:23

I use a small hydraulic jack and a 1 x 6 board when dropping the tank. When near-empty it is pretty light and very easy to control. But I like your tube idea, clever!

Post by **E Showell** » 13 Aug 2017, 18:24

Stew -- J hose was culprit after my mechanic smoke tested for my P0455 gross evap leak in the '99 S70. Try the Occam's Razor approach before you drop the tank.

Post by **abscate** » 13 Aug 2017, 19:09

Be careful and don't run with Occam's razor

Post by **mecheng** » 14 Aug 2017, 07:54

Try squirting WD40 inside the purge valve, it cured mine. I think they stick occasionally.

Post by **sleddriver** » 14 Aug 2017, 14:28

I built a smoker a few years ago. Looks like it's time to use it again.

J-hose: Frankly surprised mine has lasted this long. So many others issues were all solved by replacing it after finding obvious leaks. It may have finally gone tango uniform this time.

I'll give the purge valve a squirt. The seal could be dry. I'll squirt the shut-off valve as well.

Post by **bmdubya1198** » 14 Aug 2017, 14:57

mecheng wrote: ↑14 Aug 2017, 07:54 Try squirting WD40 inside the purge valve, it cured mine. I think they stick occasionally.

That's interesting. Do you know if they're supposed to click? Both mine and my cousin's purge valves click pretty loudly, and we both have an occasional P0455 appear. Maybe this fix will work?

Funny this thread came up, P0442 popped up today. Oddly enough, without its best friend P0455. Car's running like crap again... I guess it had a good weekend after replacing the alternator.

Post by **shaker_chi** » 14 Aug 2017, 15:31

If you have a 98 you may not have the J hose. The early 98's didn't have it. I spent an entire weekend looking for my leak and eventually I bit the bullet and took it to Car X and they smoke tested it for $65.

Post by **98v70dad** » 14 Aug 2017, 20:49

I chased this for nearly a year and never paid much attention to the gas cap since I replaced it with an new one from the dealership because I liked the tether on it. After about a year out of total frustration I bought one of those generic caps from an autoparts store, carefully removed the seal and put it in my original cap. While I was at it I noticed that the top of the fill pipe had some sharp gouges in it so I burnished them out with fine grained sandpaper, cleaned off the dust, put the cap on and PO455 finally went away to haunt someone else.