Seized Knott/Ifor Williams braked trailer hitch

[anto]

I have an ifor williams trailer here with a seized hitch brake, therefore no brakes, also no articulation either really.
Any idea on how to unsieze?
It was left outside with its rubber boot ripped off and never seen a drop of grease!

Is it just a matter of heat/ penetrating fluid/ sledgehammer until it moves?

Thanks,
Anton

 

[slim_boy_fat]

Try soaking/drowning it in 50:50 acetone and ATF mix first, then some heat if necessary.

 

[anto]

I have doused it in red diesel and hydraulic fluid for the last few days but no bueno. Nothing in the hitch that would melt if I hit it with heat? (Rubber boot excepted of course)
Also only have a plumbers gas torch so cant see it getting too hot anyway.

 

[brightspark]

a big hammer and heat

 

[rtcosic]

The Neighbour had a well corroded one from a boat trailer. I electrolytically cleaned it over a full week, removing and pressure jetting down every day.
Then put it onto the little plug-in single ring induction hob covered in a fire blanket for many hours so it heat soaked to around 250C.
Then gently persuaded the hitch to move with a modest-sized sledgehammer.

He was surprised I managed to resurrect it all.

 

[wyn]

Nothing in the hitch that would melt if I hit it with heat?

There's probably a gas strut down the centre of it.....................it might explode?

 

[8ob]

Its probably going to be easier to strip the hitch and knock back 11 with a wooden block and mallet, hot spanner may help.

Bob

 

[hotponyshoes]

Watch out for number 9 if you are heating it.
Or, hook it onto the back of a car and give it an Italian tune up.
Pumping grease in as hard as you can might push a bit of crud out as well?

 

[anto]

Watch out for number 9 if you are heating it.
Or, hook it onto the back of a car and give it an Italian tune up.
Pumping grease in as hard as you can might push a bit of crud out as well?

Tried that. Grease was going nowhere!

 

[anto]

Its probably going to be easier to strip the hitch and knock back 11 with a wooden block and mallet, hot spanner may help.

Bob

Think il just take the hitch off and remove all as suggested ^^^^^

 

[bigegg]

The only thing I will add is try tickling the sliding part with a wire wheel to remove as much rough rust as possible.

If you use percussive maintenance, beware of bending/cracking the socket.
DAMHIKT.

 

[rtcosic]

The Neighbour had a well corroded one from a boat trailer. I electrolytically cleaned it over a full week, removing and pressure jetting down every day.
Then put it onto the little plug-in single ring induction hob covered in a fire blanket for many hours so it heat soaked to around 250C.
Then gently persuaded the hitch to move with a modest-sized sledgehammer.

He was surprised I managed to resurrect it all.

Reading the subsequent posts I now realise the one I was working on was very old - maybe even a 2" one. It did not have a hydraulic damper, only springs.

So the use of 'whole body' heating isn't recommended after all!

 

[Justme]

a big hammer and heat

That will melt the plastic bush.

Not shown on the exploded diagram as its not replaceable.

 

[anto]

Finally got at this in earnest.
Removed the hitch from the trailer.
Stripped down all ancillaries, damper, handbrake, grease nipples etc.
Wire wheeled the rough bits that were visible. Soaked in diesel.

Tried sledging it but no good.

Resorted to sticking on the press....15t of pressure on. Left it loaded and then heated it as much as I could with a plumbers torch.

Eventually it went with a bang. Scared the bejesus out of me!

 

[anto]

To update;
Got it back together. Cleaned up the shaft with the wire wheel and also a gentle touch with a worn flap disk on the really bad areas. Greased up and it is lovely and smooth in the bore of the hitch.
Should work well although I reckon il have to get at the actual brakes next as they couldn't be in great condition.

 

[Munkul]

The brakes might be absolutely fine - they won't have done anything since the hitch seized up

Is the emergency locking brake mechanism up to snuff? The older ones with the ratchet instead of energy-store are a bit crap... I have one and it's borderline.