Woods BH80x broken boom cylinder

vic4news · Aug 4, 2013

I was using the backhoe to dig out some stumps today. I pushed on a stump with the back of the bucket and the dipper cylinder broke at the cylinder rod end. I have over 400 hours on the backhoe and have easily dugs out over a hundred stumps.

The break looks just like the one that westbrooklawn had in this thread. http://www.tractorbynet.com/forums/parts-repairs/231920-woods-bh80x-broken-cylinder-end.html

I'd like to have a new cross tube welded onto the cylinder as was done in the other thread. Can anyone recommend a good hydraulic shop in the Manchester, NH vicinity?

Attached pics:

Leejohn · Aug 4, 2013

That looks like it has been brocken for awhile. You need a good welding shop not a hyd shop.

vic4news · Aug 4, 2013

Leejohn said:
That looks like it has been brocken for awhile. You need a good welding shop not a hyd shop.

I just took off the broken end that fits around the pin. It does look like the top part of the tube has been cracked for a while as the metal is not shiny there. Also, the tube is elongated on the side that attaches to the rod, so it looks like stress from pushing with the bucket over the years is what weakened the tube. However, it's easier to take down trees and remove stumps using the bucket to push occasionally.

Good point about this being a welding repair more than a hydraulic repair, although I would prefer a shop with experience with welding hydraulic cylinders. I've never welded on tube before, so I don't want to attempt the repair myself.

Vic

CJONE · Aug 6, 2013

Looks to me like the cross tube broke not the weld. I would have a new tube built. Old one looks thin to me. No real trick to welding the cylinder, just protect the chrome where it goes into the seal and don't put too much heat in to the rod to discolor it and extend the rod all the way out. I will use a air gun to cool it after every pass, do not use water. I prefer 7018 to weld it with but have used a mig with no problems also. 2 ways to square up the cross tube either with a jig or just put it in the machine and tack it up. That cylinder is small enough to do that with. Use heavy enough tacks to they don't pull or break when you weld it up. CJ

vic4news · Aug 7, 2013

Yes, the cross tube is what broke because it was too thin.

The good news is that the cylinder has been repaired thanks to a fellow TBN member, Bill (aka wdchyd).
I brought the cylinder to him and he removed what was left of the old tube from the end of the rod, and
then welded a new cross tube thicker than the original onto the rod. He did a really nice job. I'll post a pic
tonight.

Vic

CJONE · Aug 7, 2013

vic4news said:
Yes, the cross tube is what broke because it was too thin.

The good news is that the cylinder has been repaired thanks to a fellow TBN member, Bill (aka wdchyd).
I brought the cylinder to him and he removed what was left of the old tube from the end of the rod, and
then welded a new cross tube thicker than the original onto the rod. He did a really nice job. I'll post a pic
tonight.

Vic

Great, sounds like he knows what he is doing!! CJ

vic4news · Aug 7, 2013

Here is a picture of the repaired cylinder with the old cross tube sitting on top of it.
The new one has chamfered edges, so in the picture it doesn't look as big as it actually is.
Bill added the chamfer so that I wouldn't have to grind some of the support metal directly under the pin.
The new cross tube has a wall thickens about a tenth of inch bigger than the old one.
Should be a big improvement over the original part.

Vic