940 That Oil Trap Return Hose

What's the best way to clean the flame trap hose going into the block without dropping the pan? I read about dumping engine flush and gently running a bottle brush down there in existing threads. But are there any serious gambles with doing it that way (beyond busting the hose) or tricks that I don't know about?
Yes, another thread about doing things the wrong way. I want to just replace the tube, but removing the oil pan involves lifting the engine. And I still don't know how to do that, or even if I'd be allowed to set up the necessary rigging here. I don't like the idea of engine flush or carbon chunks floating in my oil at all, but I'd be changing it and probably dumping some clean oil through the system immediately after.

I just replaced mine, but with the engine out. The tube is held in place by a bracket that shares a screw with the oil pump. The oil pump additionally has a wimpy little notch to try to keep the hose in the right place. Tube is longer then the oil pump itself iirc.

That said, the hose kinda more or less points at the drain plug and resides in the lowermost portion of the oil pan. I'd try taking out the drain plug, blasting in some mild cleaner (maybe seafoam) with something that can spray liquid forcefully (AC flush kit, if you have it?), let the liquid directly drain out, and when you feel like it's all clean, pour in maybe a quart or two of cheap walmart oil from the valve cover and down the tube to wash everything out of the pan that might not have escaped past the drain plug...

That last little part is tricky (I have another thread griping about the engineering of the oil sump area), as the oil pan has a flange welded in place for the drain plug, but it rises above the bottom surface of the pan, which means junk can just get trapped there.

I don't think anything coming out of your PCV drain hose would damage your oil pump, so maybe just fill er up with cheap oil, drive around for a couple miles and drain and refill with good oil, as a "flush"

If it makes you feel better, my engine runs great and the oil pan was nasty. Not sludgey, but like a wendy's deep fryer vat at the end of the day. Lotsa little brown/black oil crumbs There's probably 5x the amount of crud just in your oil pan as opposed to inside that tube.

Thanks, that does help. I'm reminded of the fun stuff I drained out of that sump in the past: bits of engine paint and coolant stop leak from previous owners, and chewed up valve hushers. I'm trying to approach the engine like a bomb squad over here, while it's happily slinging failed bits of its own parts around the pan without missing a beat.

iamrolling said:

lifting the engine

Click to expand...

On a concrete floor, a cherry picker can be placed perpendicular (T-boned) to Volvo's passenger side so picker's "hook" is pulling upwards on thermostat-housing's lift-anchor an inch or two (when motor mount's nuts are removed). Cherry picker can be moved towards or away from vehicle to rotate engine just enough so oil-pan (or motor mounts) can be removed. Here's my brief write up - As noted there, "I used a floor jack on driver's side to raise driver-side's body" I said vehicle's body, like is done when changing a flat tire.

While doing return-hose replacement, I found passenger side motor mount was shot...so I replaced both motor mounts, one at a time.

Here's Art's Page - http://cleanflametrap.com/oilpan/

I was looking for the hoist in Art's series of images, but it looks like he's lifting it by turning a nut on top of that electrical channel, attached to a threaded hook through the thermostat loop instead. Is that what I'm seeing? Instead of a hoist, a heavy steel hook that raises through a metal bar?

iamrolling said:

I was looking for the hoist in Art's series of images, but it looks like he's lifting it by turning a nut on top of that electrical channel, attached to a threaded hook through the thermostat loop instead. Is that what I'm seeing? Instead of a hoist, a heavy steel hook that raises through a metal bar?

Click to expand...

He's using a homemade version of an "engine support bar" (commercial versions available at Harbor Freight, etc). Less max lift but smaller and more convenient for many jobs if you just need a few inches upwards.

That's awesome. I have to make one.

Footnotes - Body is attached to front-suspension-engine cradle, so I loosened passenger side bolts most of the way, and removed driver's side bolts.

Two lift actions are involved:

(1) lifting engine above cradle an inch or so, and
(2) lifting body with vehicle's jack on driver-front side an inch or so at body-suspension mount plane (where bolts were removed).

I removed all the stuff (intake, alternator, AC) on driver's side to make it easier, but this is not required. In this process, I found some loose bolts/nuts....and replaced both motor mounts. YMMV...

Got it. Took off the breather box and funneled engine flush in until I could hear it draining quickly into the sump. Drained the oil, dumped some more oil in both the fill port and the return hose. Put on a new oil and filter and primed the filter with the starter. Cleaned the throttle body and greased the linkage along the way. I can't smell any residual engine flush fluid, and the engine didn't grenade when I went for a drive.