Hydraulic ram refurbish

[Bensdexta]

Can anyone suggest where I might get the rams of my front loader repaired? Unfortunately the chrome surface on the piston rods is damaged.

Any advice appreciated.
Thanks,
Ben

[michael dyer]

My experience with getting hydraulic rams repaired for farm machinery is that it is usually more cost effective to have a new ram made, they can be manufractured to virtually the same dimensions as the orginal with matching hole sizes etc.

I guess there are lots of these companies out there if stuck I have a contact for a company in Bridgwater (Somerset)

[Bensdexta]

I guess there are lots of these companies out there if stuck I have a contact for a company in Bridgwater (Somerset)

Yes please I would like to have your contact.
Many thanks,
Ben

[Nevis]

I have a Horndraulic loader ( I think the same as yours) and the rams are plain steel without any chroming. This causes no issues with function or leakage I think because the rams are single acting so a pressure seal is not required between ram and outer seal. The reason for mentioning this is that they may work perfectly well without spending money on chroming or replacement

Andy

[Tubal Cain]

I was informed by a friend who worked at Dowtys that chromium plated bars of various diameters are available from which replacement rams can be cut to length and the ends machined accordingly. There must be firms up in the North West who can supply new rams and suitable seals, or who will recondition the rams for you.

Gerald

[Bensdexta]

Andy,
Thanks for your advice. I'm pretty certain my rods are chrome plated. Can someone tell me if the seal at the top of the cylinder, through which the chromed-rod passes is the one and only seal, or is there another seal at the bottom of the rod, sliding on the internal wall of the cylinder?

I think there is a hydraulic shop in Whitchurch (Egerton) - any experinece of them? Perhaps I should try the rams first.
Thanks,
Ben

[Nevis]

Ben
My rods are not chrome plated (I have to keep them oiled to prevent rust) and the rams work perfectly- so yes I reckon you should try them first before deciding to spend money.
Andy

[Mike Kuscher]

Hard Chroming is, of course, carried out by 'industrial platers'.
The 'finishing' process though is 'cylindrical' or 'centreless' grinding.
It is not usual to find many companies who do both processes.
Also, the rams will need the old chrome 'stripping' first.

This whole thing though, is something very common with manufacturing or repairing 'Pressure Dies', 'Plastic Moulds' or 'Press Tools'.

Just happens to be 'my old job'. So here's my advice...
Go look for a small, local Toolmaking Firm working with tools for Diecasting, Plastic Moulding, or Pressings.
Talk to them 'nicely' (otherwise it's not too cheap and you want a 'favour').

They will be able to measure the existing size (over the chrome), cylindrically grind the old chrome off (quicker and cheaper than chemical stripping), send the rams to their favourite plating company and ask for 10 thou hard chrome (must be HARD, soft chrome is looks only and flakes off) then cylindrically 'finish grind' to 'size'.

(Sorry! not in 'that game' any more)

Avoid anyone who offers to 'spot chrome' the 'missing bits'. Won't last 5 minutes !

Mike

PS. Just read your reply whilst I was typing this one.
You rams are guaranteed to be chrome plated steel.
Solid Chrome bars don't exist, they would be several thousand pounds EACH !

[Brian]

Horndraulic loaders came with plain steel pistons or, for extra cost, chromed ones. Either will work.

[Bensdexta]

Horndraulic loaders came with plain steel pistons or, for extra cost, chromed ones. Either will work.

Brian,
Thanks for the clarification.
Which is the most important seal, the one at the top of the cylinder or the one at the bottom of the rod?
Thanks,
Ben

[Brian]

There is no seal on the rod it is a displacement ram. The only seals are "O" rings in the cap and a dirt seal right at the top.

[Bensdexta]

There is no seal on the rod it is a displacement ram. The only seals are "O" rings in the cap and a dirt seal right at the top.

Thanks for clarifying that. So damage to cap seals and rod surface is likely to result in leaks.

[Bensdexta]

As Brian pointed out, they are displacement rams, so there is only one main seal at the top of the cylinder and damage to the chrome rod is likely to result in leaks.
I've had a couple of quotes for repairing these rams. Seems to be a fairly standard repair involving manufacturing new chromed rods, fitting a new seal pack and testing. Cost per ram £150-£200. I'm still investigating a Kuscher sneeky repair

I think I'll see how badly they leak before spending the money.
All the best,
Ben

[dexta4]

http://cgi.ebay.co.uk/HYDRAULIC-TRACTOR ... 7C294%3A50

[Bensdexta]

Thanks. I've asked him what is the condition of the rod surfaces.
Ben

[dexta4]

they look ok in the pics but you never know whats on the other side

[Tmac]

I take that displacement cylinder means a one way cylinder? I have never heard that term.

Here is what can be done on the cheap.

It seems that the chrome is coming off near the end of the stroke. Most likely cause for this is a worn rod guide bushing, not uncommon. Also would suggest the piston is worn too. The piston should be attached by either a snap ring or locking nut. In most ag type applications this piston is made from cast iron. This piston is more than likely worn on the edges from tipping at the outer most extension. This is from the guide bushing being worn. It will also mean the bore is worn oval some too. If not oval bell mouthed, tapered. Near the extended end. You may also have scoring which has to be fixed if any of the scoring is raised or has sharp edges. The cylinder bore needs to be smooth.

Repairing the chrome for use "as is" can be accomplished, 1. Buffing, cloth or sisal wheel using chrome polish on the wheel, the rod with a power buffer. 2. by crocus cloth either by hand or in a lathe. 3. By use of a die grinder and rubber, emery embedded, wheel. This would entail doing each spot individually by hand. You need to feather edge the chrome on each bad spot. This has to be done to prevent further peeling. There can also be no raised galling on any of the exposed steel base metal of the shaft, which none can be left either. Small rounded smooth dents left, usually will work.

The guide bushing and the piston will need to be replaced. The bore of the cylinder will need to be honed if rough. This is only a "fix up" repair and sometimes just dont get the job done. But I have done many this way, that have worked. I have a forklift that this was done by me to, on the main lift cylinder, 18 years ago and is still working.

[Brian]

Tom,

A displacement cylinder has no seal on the piston and has a slight dish/flat on the bottom of the piston. This prevents it coming straight out of the cylinder.

To lift, the whole cylinder fills with oil and the pressure builds up. Pressure is transmitted equally to all areas within the cylinder and onto the piston. Because the surface area is greater on the bottom of the piston than it is on the top surface (because of the piston rod) the piston rises, lifting the load. This is the "displacement" part

The only oil seals are usually "O" rings around the cap and onto the piston rod. There are no internal seals on the piston. Of course the cylinders are only single acting and not double acting.

The only guide bushings are usually part of the cap which typically, is an aluminium one. I have seen them get worn and allow the piston to "cock" to one side and jam up in the cap. As you can see, this is very dangerous as, with the cylinder empty of oil, a slight jar and the loader will come down like a rat trap. (Been there, done that, missed me).

This loader was made for Ford by a company called SteelFab previously known as Horndraulic. They were one of the most popular loaders in the 1950's through to the 1970's and made loaders for all the major manufacturers like Massey Ferguson and Ford under their own names and colours. They also made construction equipment and back hoe fittings.

From what I remember there was about £10.00 difference between the cost of a loader with steel rams and one with chromed rams when I was selling them.

Sorry if I'm "teaching my grandmother to suck eggs" again.

[Lesfen]

Brian,

Thanks for explaining the operation of a displacement cylinder. We have them on post pounders here and I always wondered how they could possibly work with no solid piston or seal filling the cylinder.

Les

[Bensdexta]

This loader was made for Ford by a company called SteelFab previously known as Horndraulic. They were one of the most popular loaders in the 1950's through to the 1970's and made loaders for all the major manufacturers like Massey Ferguson and Ford under their own names and colours. They also made construction equipment and back hoe fittings.

Brian,
Thanks for the background on SteelFab. There's an interesting page on Wiki: http://en.wikipedia.org/wiki/Steelfab which says:

"In 1949 SteelFab who were based in Cardiff, negotiated a licence with Horn Brothers USA, to manufacture and market agricultural hydraulic loader attachments and well over 100,000 "Horndraulic" loaders were sold. In the early 50's it was decided to go into the Backhoe market, which resulted in the introduction of the "Scout" Digger, manufactured under licence to the Shawnee Manufacturing Company of the USA.

In 1952 a subsidiary Company was formed in Australia and this Company had a modern plant on the Moorabbin Industrial Estate near Melbourne, Victoria.

In 1954 a licence was finalized with the Shawnee, to manufacture and market "Shawnee" industrial loaders and diggers.

In 1959 Steelfab initiated a project to introduce a Combination Unit as opposed to the Shawnee Warrior type attachment digger. The Steelfab Unit was designed to fall between the JCB4 and Massey Ferguson Backhoe loaders models.

Several hundred 160/180 combinations units were build but the early models were built on the light weight Fordson Dexta skid unit which was not strong enough to carry the stresses produced by a backhoe loader and units started to fail."

Units were also produced for the stronger Ford 5000 skid and the Steelfab SF 122 loader was used to build the "Roadless 700" Tractor loader in 1968, based on the Roadless Plougemaster 65 and 75 tractors.

It seems SteelFab eventually fell victim to JCB amongst others, in the backhoe market ceasing production in the early 70's.
All the best,
Ben

[aldo]

Well I'll be, that's amazing Ben.
The FEL on my Dexta (you may have seen the photos), has a plate on the side saying 'designed and manufactured by Cranes and Shovels, Pty Ltd, Moorabbin, Victoria '. I wonder if that's the subsiduary company you mentioned.