Repacking/rebuilding a cylinder

gemini5362 · Apr 19, 2007

JerryG said:
The reason that the seals are blowing is because you have the bucket angles down to much. You aren't blowing the seals because of the hydraulic pressure, you are blowing them because of the amount of force that the tractor is putting on them. The bulk of the force needs to be on the pins where the bucket is mounted. By having the bucket angled the way that it has been, all or almost all of the pressure from the tractor pushing is being directed to the packing in the cylinders.

Hi JerryG

spring time in the ozarks does life get any better than this ?

JerryG · Apr 19, 2007

The relief valve is on the other side of the valve. On the tractor side. When the valve is centered, the cylinders are isolated from the relief valve.

Hi JerryG

spring time in the ozarks does life get any better than this ?

The weather is have been just fantastic the last couple of days. I wish that it was like this year round.

gemini5362 · Apr 20, 2007

I never knew that about the relief valve thank you for that information.

I dont want it like this year round I enjoy the thrill of it being so nice. I have to have something not nice to compare to for it to be a thrill.

slowrev · Apr 20, 2007

JerryG said:
The relief valve is on the other side of the valve. On the tractor side. When the valve is centered, the cylinders are isolated from the relief valve.

Hi JerryG

spring time in the ozarks does life get any better than this ?

The weather is have been just fantastic the last couple of days. I wish that it was like this year round.

yes I made that point earlier in the thread, but perhaps not a clearly.

chanceu · May 1, 2007

Is there a special tool used to remove the cap or is it just a big wrench? Does anyone know how much torque should be used when tightening the cap?

KJM · May 1, 2007

chanceu said:
Is there a special tool used to remove the cap or is it just a big wrench? Does anyone know how much torque should be used when tightening the cap?

You need what in Australia we call "Crescent Spanners". In the US, "Crescent" is a brand and means something different.. The proper tool is a circle segment with a handle and pin that engages in the pin on the rim of the cap. If your cap has two pin holes on the end - then there is a wrench like you use on an angle grinder to tighten the friction disc.

Now, I'm all for using the right tools - BUT - my backhoe and loader between them have 4 different diameter cylinders and hence would need 4 different wrenches. So I used a 1200mm (4') pipe wrench I use for 3" pipes

It leaves a mark, of course, but it isn't a big deal. Just carefully put it on the exposed edge of the cap. Some caps with the pin drives on the ends screw in internally. If you have one of those, you'll need the proper pin drive spanner.

Undoing the caps on the backhoe required a cheater bar on the end of the pipe wrench handle and me "bouncing" to loosen. (Recall mention of 400lb Gorillas!). This is why you need to leave the cylinder attached with at least the bottom pin.

Doing it up was no real drama - the caps hydraulically seal with an O-ring - just like a standard SAE port on a loader valve. So the sealing is O-ring - no need for insane torque. SAE fittings will seal "finger tight", in fact, but that is certainly not the recommended way to tighten a loader valve port! So all I have done is do the caps up with my trusty pipe wrench tight. The backhoe has done about 100hours since without any problems at all.

I guess it would be possible to kiss off the pipe wrench marks with a file, but I painted the cylinders before re-installing and you'd be hard pressed to see them as anything but "new looking".

Hope this helps
/Kevin

john_bud · May 1, 2007

Yeah, we all have used pipe wrenches .... but.... they are really not the first choice in tool. A pin wrench can be had off e-bay for 20-30 bucks.

Issues with pipe wrenches are the obvious teeth marks, and the less obvious but more serious distortion of the cap. This only occurs when a 400 pound (that a 180 kg gorrilla for you Ozzies...) puts the cap on. A pipe wrench will squeeze the thing it is working on and if you apply enough force (3 foot breaker bar - 1 meter Ozzie!) it will put a lot o squeeze on and can deform the cap enough that you may have to spend some $$$ on a replacement.

G'day!

jb

gemini5362 · May 1, 2007

Would that be dollars or pounds to the aussie?

chanceu · May 2, 2007

It's dollars either place.

Unless I misunderstand, both KJM and john_bud have mentioned a wrench that enganges holes on the side of the cap. My cylinder caps don't have holes, just two round sides and two flat sides. These are fairly small cylinders, 2 1/8" from flat side of the cap to flat side of the cap.

As for a pipe wrench, I'll take the cylinders to the dealer and get them repacked before using a pipe wrench. I've found service/pump wrenches that size (around $30), but I'm not sure they'll work. The other options are a regular wrench or a large adjustable wrench which would both be around $100.

bones1 · May 2, 2007

Have you been successful finding spanner wrenches?.I am also looking for something to remove the "round nut" on both my loader cyl.Mscdirect has about200 different ones