Can penetrating fluid loosen a seized nut where heat couldn't?

Ectophile

force_ten wrote: »

my first thought was they cant undo it it adjust it but they can undo it to replace it

I suspect that's "undo" with an angle grinder.

n217970

seatbeltnoob wrote: »

The people at national tried but could not align it saying that the track rod assembly is sized and the nut won't move.

Since you sound happy to get your hands dirty the first thing I would do is get a spanner on the nut and try to turn it. I expect it will move with moderate effort. Just because somebody says it is seized doesn't mean it is.

System

force_ten wrote: »

my first thought was they cant undo it it adjust it but they can undo it to replace it

World of difference trying to free something off to adjust it which will be used again and freeing something off that you know will be replaced. You can go full on neanderthal on something you know is going to end up in the scrap bin because it doesn't matter what you do as it doesn't have to work again.

IamNotAllowedToUseMyName

Ultimately. whether heat works depends on the materials. Some hardened nuts and bolts may not be particularly expandable due to heat, so neither heat nor cold will make much difference, and if there are fittings around that can be damaged by heat, then you can't apply enough heat to get the threads to move relative to each other.

If the materials are different, then sometimes you can get a differential expansion/contraction with heat/cold. What you are trying to do is persuade the rough surfaces to move relative to each other.

There are two reasons why it might be stuck, simply too tightly compressed together, so penetrating oil allows the surfaces to slide more easily. The other reason is different metals react so you get corrosion. Oil can help to some extent but typically does not cure the corrosion, so if something is bonded due to corrosion, then oil will struggle to dissolve the hidden corrosion. Tend to see this more on push bikes than cars (e.g. steel seat post into alloy frame).

esmerobbo

Have you checked it is not a left hand thread?

sevenhills

I am very skeptical that penetrating oils work at all, any better than ordinary oil.
When a nut and bolt are seized, there is zero gap; I am sure you can find adds saying how well they work.
But has there been any science based tests done? Heating until red hot clearly works.

peter12345678910

n217970 wrote: »

Since you sound happy to get your hands dirty the first thing I would do is get a spanner on the nut and try to turn it. I expect it will move with moderate effort. Just because somebody says it is seized doesn't mean it is.

With a Deep impact socket, they use them on planes.

tedted

they are talking about the nut that locks the track rod end to the axle rod,they cant turn the rod to adjust the tracking and heat would damage the t/rod end

onomatopoeia99

esmerobbo wrote: »

Have you checked it is not a left hand thread?

This. Had that on a car I took for tracking once, the bloke was swearing like a docker at it because he couldn't get one of the nuts on the steering arm undone and hadn't noticed it was a reverse thread. :rotfl:

droopsnoot

seatbeltnoob wrote: »

I saw an assembly only costs £29 (lemforder) per wheel. So they are trying to charge a bit too much in labour for my tastes.

Possibly true, but then it might just be because they already know (or think they know) that the nut is seized so it will take some removing, and are covering themselves with a higher quote rather than going in low and having to either (a) eat the extra time, or (b) annoy you by charging more than they said they would when they can't undo it. Or, of course, (c) pricing high so you'll take it somewhere else.


I've heard (but not tried) that a mix of 50/50 Acetone and ATF (Automatic transmission fluid) is the latest wonder releasing agent.