Need advice on cleaning oil lines...

[JP911]

I recently purchased used external oil cooler lines for my P-car. I picked up both lines between the engine and the thermostat as well as the solid lines from the thermostat to the cooler. The lines are in pretty good shape, but I want to give them a good internal cleaning. I was thinking I would fill them with degreaser and let them sit for a few days. Is this a good idea? Will it damage the flexible section between the engine and thermostat? Any advice is much appreciated!

Thanks,
Jon

[mtelliott]

Did you ever get a good reply on this? I'm getting ready to do the same and was wondering if you learned anything.

[MotoSook]

I installed an entire oil cooling system from used parts, and all I did was spray a lot of degreaser (Gunk and everything else I had in my garage) into the lines. The outsides are not that important, but I did want the crude off so as to be able to easily spot a leak. I didn't let it sit overnight, no need to unless the PO of the parts ran crude through there. I let them sit for 15 or 20 minutes then thouroughly flushed with a garden hose. Hung them on the fence to dry and then blew them out with the air hose just for grins. The results were clean inside surfaces and relatively dry out side surfaces. I think a little oil on the outside material keeps them good longer.

If you want, you can plug one end, fill the hose/tube with the degreaser, then hose them out after an hour or so. That would be extreme enough. If there was crude in those lines, repeat.

Remember, the car the hoses came off of, may have had fairly clean oil circulation through those lines all it's life. If not, the degreaser will do a good enough job. If the hoses came from an engine the chewed itself to pieces, just flush longer. Anything from the scavenger pump has to go through the filter, but it doesn't hurt to help the filter. The lines from the tank to the pressure pump are short and can be cleaned easily.

It doesn't have to be rocket science.

Edit: outsides are important, but not critical, just get them clear of crud. Crud prevents heat transfer. Clean the cooler inside and out as lone as you have the system apart.

[Early_S_Man]

I think Varsol heated to 120°F and recirculated by a parts washer pump ... would be the optimal cleaning method. Easy it wouldn't be, though, and a lot of work with metal conduit of 1" size or larger ... I suspect! I would want to filter any return fluid before the pump.

Also, it would be a possible fire hazard if done wrong and left running without close observation!

[HarryD]

Depending on where the lines came from, you may have an issue of debris from the PO's blown up motor in the lines. Yyou might want to consider "pigging" the lines by blowing some "lint free" cloth balls through the lines to verify no solids.

[JP911]

mtelliot-
I'm surprised to see this thread re-surface. As there were no responses, I just flushed them with degreaser for a few hours and then cleared them with a hose (as Souk suggests above). I repeated the process 2 times to make sure that everything was clean. I also cleaned the outsides and then used brass polish to really clean them up. What can I say, I'm really anal.

[Tim Walsh]

Hmm.. I'm having the same problems myself since my windage screen decided to disintergrate on me. The filter didn't have any particles in it, only one or two bits in the tank and a few in the sump screen. The peices were big enough 90% of them (all 9 or so of them) that the sump screen caught them. The other peices ended up on the tank magnet.

I know I need to clean out the lines but how critical is this going to be?