Wrecker: Unseizing Boom Jacks

[zebedee]

Top bracket finished - time to give it a go.

View attachment 667463 After applying enough pressure to find the inefficiencies in the design/fab, with ensuing repair and strengthening, I cranked the jacks up then started to heat the outer tube, from top to bottom in a narrow strip. Add a little bashing - not enough to damage the surface of the tube, I pumped the jacks a bit more then checked for movement. Initially I couldn't really tell if it had free'd up - so I heated more and jacked more... then presto.

View attachment 667464
After that - I kept on with the jacks and got a few inches of extension.

View attachment 667465View attachment 667512
During one of the heating sessions, water or condensation started to pop out of the pin hole. I guess the air inside expanded and pushed it out.
View attachment 667467

I guess at 40 tons of pressure, I have exceeded the capacity of the eye. So there will be some 're-rounding' when I get done with the separation of the two halves.

 

[gimpyrobb]

Pics no worky.

 

[zebedee]

Don't know what's up - they are there when I edit!!

No they are there too much! I D K...

 

[zebedee]

https://www.youtube.com/watch?v=3DC_Pmp6KPs&feature=youtu.be


this is a very brief clip of the condensation popping out of the pin hole! It surprised me so I thought I'd try do the youtube thingey...

if this can come out - it means that the unsiezing solution has a pathway in.

 

[Recovry4x4]

Mother nature, the inventor and primary user of the cold weld process.

 

[gimpyrobb]

I can see them now!

 

[zebedee]

Update: Managed to get the second boom jack freed up - as much as the jacks and some blocking can achieve.

The second one took a lot more heating - pretty much went up and down the whole tube - below red hot. This also burnt off a load if the cruddy paint too.
I'll leave them overnight with the penetrating fluid now running into the joint between the tubes and the pin holes. These tubes fit pretty tight, they are matched telescoping sizes OD to ID, not just the next size up.

I noticed that the second one had a slight bend at the very bottom - last 3' or so, this would naturally add to the force required to pull them apart. Now that they are both unfrozen - up to 18" separated already, I'll resort to the crane to finish the separation or between the two trucks maybe. Subject to whether both the tubes are bent or if the outer is bent and the inner was pushed in to follow, straightening will be attempted.

All in all, it took a tremendous force to free them up - and copious amounts of heat was needed.


Press tool is now done with - probably throw it in the a disused corner of the shop. It took quite a beating but will still fit and would work again.

Next step is to make a swedge tool to re-round the ovaled eyes....

 

[Csm Davis]

Wish you would have called me bud I could have probably saved you some time and effort. But now you have them apart I would clean them up real good then a light coat of Ez-slide will keep it from rusting and add a dry lube to keep them working.

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