Hydraulic cylinder reseal

This is not a Ford unit, but a single action 3.5" ram cylinder on a forklift - no maker's tag or any identification that I can find, it dates from the 1950's - I removed the cylinder a few years ago and took it to a shop, it was better after that, but still leaked and it's gotten worse - it's a PITA to remove the cylinder and I can remove the retaining nut and o-ring/seal retainer with the cylinder mounted on the machine -



I found 4 of these cupped composite seals stacked on top of each other - one is ragged the others look good - and an external and internal o-ring - the internal o-ring is 'vented' and I think is mainly for dust/dirt exclusion -



I'm not sure why there are four seals -

anybody here with experience? there doesn't seem to be anyplace on the larger board that is for hydraulics - if anyone is aware of someone posting elsewhere on this forum who is recognized as 'expert' on this, please advise me -



I'd like to get this sealed better, but am uncertain of what I'm doing - where does one purchase seals/o-rings for this sort of thing? I could likely get o-rings at one of the supply shops in town, but don't have a clue as to who supplies these cupped seals
thanks
David

Any decent hydraulic repair shop should be able to match them. Since you had it at a shop before why does it still leak. They should have inspected the rod and cylinder.

Those look like Vee packings, sometimes known as Chevron packings.
The stack usually consists of a male adapter on the bottom, multiple
Vee rings in the middle, and a female adapter on the top. Usually you
find them on pretty old equipment. They are still available at Baum
Hydraulics or a Seals and Packings house such as Zatkoff. Your local
hydraulics shop should also be able to get them.

...why does it still leak?

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Good question - several possibilities - I'd guess the main factor is the ram not being what it used to be, but I don't know - - I just checked and the shop I took it to (this was probably 10 years ago) seems to still be in business, tho some distance away - I'll likely run over there Monday and chat with the fellow - -

This is a weak point in my knowledge base, I've never done much work on cylinders -

Thanks, Andy - does this male adaptor stay in the cylinder? As I recall, when I got the cylinder back from the shop the fellow told me that if it leaked to tighten the nut at the top, which I have done a couple of times, but while it's usable, I'm running thru 15+ gallons of oil a year - - this unit is real handy and does get used nearly every day, but I hate the oil spots where it sits -

The adapters just make the top and bottom of the packing stack flat,
so yes it stays in the cylinder.

<img src = https://s19.postimg.org/uqm5k59df/Vpack.jpg>

Thank you for that scan, Andy - it discusses details of which I was unaware - I'll be doing some internet research today utilizing this new knowledge -

10 years on a cylinder used daily is not the shop that rebuilt it's fault! I am all for standing behind my work but after 10 years it's not anything the shop did wrong pomester!

I'm not blaming the shop - it's an imperfect world and there's only so much you can expect from 60 year old equipment (what you can expect is continuous maintenance) - I think they did as good a job as possible with what they had to work with.

It just needs to be done again, and I'd like to avoid removing the cylinder. It's heavy and in a hole and I did it myself last time, but I'm uncertain I could do it again without help.

From the bit of research I've done now, it looks like the question is the condition of the 'male adapter', which is inside the cylinder - Zatkoff, referenced in Andy's post above discusses wear of the adapters as being a big deal - in this unit the female adapter is an integral part of the brass o-ring retainer and the male adapter is down in the cylinder and I doubt I'll be able to remove it short of removing the cylinder from the machine. I'm just guessing that it is brass also and how worn it is is unknown.

Dunno - plan as of right now is to get new 0-rings and V-packings, maybe use 5 V-packings instead of 4, put it back together and see how tight I can get it.

Don't forget the quality and cleanliest of the oil plays a role also. Was the inside of the bore honed?

Don't forget the quality and cleanliest of the oil plays a role also. Was the inside of the bore honed?

Click to expand...

dunno -

I had a nice chat with Mark from Zatkoff today - they are sending me a half-dozen V-packings @$5.90 each - - I'll pick up new o-rings locally - when the cylinder was rebuilt it was disassembled and they did a nice job cleaning the ram, I'd guess they addressed the bore also - inspecting from the top I can see the bronze male adapter in the bore and the area looks uncorrupted

I also inadvertently flushed a couple of gallons of oil out of it today by running the engine with the control lever locked in the 'down' position - who knew? - there's a filter in the system and I've been running TSC's cheap hydraulic oil - it looks good -

I've been servicing the whole unit, pressure wash, all new fluids, new air filter, carb rebuild, pulled the distributor and reconditioned, (cannot find any timing marks on the pulley however...) new regulator/diodes in the alternator, new belt, new fuel line, tidy up some wiring, etc, etc - - this tractor was rode hard before I got it and fits right in with the rest of the fleet -