Oil pipe replacement

[Guest]

I am in the process of replacing the two oil lines from the oil thermostat to the engine and the oil tank, just one small problem with this, I can't get any of the oil unions free!
I have tried long levers, a plumber's torch for a heat source, I had them soaking in penetrating oil over the winter lay off , with no success at all.
Does anyone have any ideas or tricks of the trade etc. that I may try? Unfortunately I live in a very remote part of the UK, so I do not have easy access to specialized engineering services, plus the car is no longer drivable due to the oil slick that follows it around!

Thanks in advance

Richard

 

[bernard tester]

Hi Richard these pipes are oftern dificult to undo as you have found you are doing the right things, you can also try useing two hammers or a hammer and a block place the block on one flat and hit on the opposing side. you can also use quite a lot of heat but take care!

 

[vitesse]

Hi Richard,the problem with heat is that you need to get a lot into the steel union nut to break the aluminium oxide film which is locking the joint without also heating the thermostat aluminium casting such that it expands more than the steel.
If you have access to a DIY plumbers freezing aerosol and make an insulating muff to fit around from foam,you could try alternate heating,freezing cycles to crack the joint but be very careful-the freezing gas is also a little dangerous.I have found the aerosol penetrating liquids which contain graphite to be better than most.Alternatives include carefully brushing either dilute acid or alkali on the visible screw threads and gently warming to get penetration.

 

[Guest]

Colin and Bernard,

Thanks for the info, I found this very useful and now I can update you on my progress: Firstly I removed the complete oil system from the oil cooler backwards, having previously cut the two damaged oil pipes in half, then I used a small angle grinder with a thin metal cutting blade, which I used to cut a groove in the union nut, until the shadow of the threads appeared. Next a oxyacetylene torch was used in the groove for four to five seconds, to make the cut expand, and very quickly a small cold chisel and hammer was used until the nut started to crack and move.
WD40 was applied, and then a spanner or shifter completed the job. And no damage at all, to the threads on the thermostat.

I hope this might help others, regards,

Richard