Hydraulic Ram Stuck

[Mark]

Hi all

Owned a Brian James Tilt Bed Trailer for probably 25 years. Used it on a very few occasions. Collected several cars with it over the years.  A couple of GT6's, Herald a few Spitfires and my Vitesse in 2006. Also 400 mile trip for my nephews MGTF ebay win and moved an mx5 for another nephew, last used about 4 years ago.

As it stands unused year in year out I have neglected it. New tyres have now cracked and I need to replace the decking. Recently I've been using it to store my Mazda Eunos. Unloaded it yesterday for an MOT it, which it passed. Tilt bed pumped up fine, but when I turned the valve to lower the bed it just stayed there and wouldn't go down.

I used a jack to support the bed and removed the pump and ram and lower the bed. Emptied the oil from the reservoir which worryingly was a mix of oil sludge, rust and a fair bit of water. Still the ram is extended and wont retract. Took the pump off the reservoir, thinking the pump oil ways were blocked with sludge, but it made no difference. The Ram appears to be an integral part of the reservoir, which looks to be a sealed unit. I used compressed air on the pipe from the reservoir to see if the ram would move, but I just pressurized the resevoir and was covered with oil/water sludge when removed.

Any ideas of what is likely blocked and any suggestions on how I might unblock it and retract the ram?

 

[Hamish]

I would try and “encourage” it back in. May be with a ratchet strap wrapped around it top the bottom 

perhaps over extended ?

I guess the external pipe is the bypass

Edited July 19, 2024 by Hamish

[Mark]

16 minutes ago, Hamish said:

I guess the external pipe is the bypass

Thanks Hamish

I did think it may be the the pipe that the pressurized oil escapes down when the valve is opened, I don't know enough though.

I did try a meaty ratchet strap around the top of the ram and a cross member on the trailer along with the weight of the bed, but it was jammed solid, and I was worried I was going to start bending things. Maybe different now the oil has been emptied, ill give it another go.

Edited July 19, 2024 by Mark

[thebrookster]

I can't tell if this is single acting or double? 

Assuming it is single, it should drop under its own weight. If so, you pump to lift and operate the lever to drop? The extra pipe may be to allow oil to fill the top of the ram, in order to protect the ram.

Two options. One, as Hamish says try a ratchet strap or a heavy soft mallet. Or even both lol.

The other is try and open the top and remove the rod, which would allow a wee service before reassembly?

[thebrookster]

2 hours ago, Mark said:

I used compressed air on the pipe from the reservoir to see if the ram would move, but I just pressurized the resevoir and was covered with oil/water sludge when removed.

Having read your post again, it sounds very much like a single acting cylinder. (Which is what I would have expected).

This means the hydraulic pressure only lifts the ram, so using air has the same effect. It's trying to push the ram further.

If the pipe going to the top is to the "other" side of the ram, then you might be able to stick an airline on that and blow the ram back down?

The other possibility for that line is as Hamish suggests, it's a bypass to stop you raising the ram too high. Once it is uncovered, oil returns back to reservoir instead of pushing the ram.

[Mark]

 

29 minutes ago, thebrookster said:

Assuming it is single, it should drop under its own weight. If so, you pump to lift and operate the lever to drop?

Thanks

Yes, that's how it would normally operate. The lever has a double action and pumps the ram up both ways, open the valve and it normally drops.

Can't access the external pipe as it enters into the sealed reservoir. As you and Hamish suggest I'll give the ratchet strap another try. 

If I tap the base of the reservoir tank on the ground I get spurts of oily water out of the short pipe bottom centre of the reservoir, but the ram doesn't move.

Edited July 19, 2024 by Mark

[Nick Jones]

I’m suspecting it’s simply mechanically stuck. Most likely corrosion around the rod seal where it protrudes into the outside world. Are there any rub marks on the chrome of the rod?
 

Trouble is, you’ve got all that hydraulic force to push it out, but nothing much to push it back…..

I was going to suggest a ratchet strap but Hamish beat me to it!

[JohnD]

From my extensive research (see Cutting Edge Engineering on YouTube:  https://www.youtube.com/@CuttingEdgeEngineering) I suspect that this ram, mounted upright on the trailer, with the top of the cylinder upwards, has accumulated dust/debris in and on that seal, and damaged it.  Kurtis' business is mostly repairing such damage!

His solution is often to remove the seal mount from the cylinder end, which is cost effective when a replacement cost thousands, but that may not be practical or economical here.

John

[Mark]

Thanks all

With brute force and not so much ignorance, thanks to you lads, got the ram to move. Heavy duty ratchet strap was not enough. In the end lost patience turned it onto the chrome ram end and bounced it onto a block of wood like a pogo stick and it gave in. Twisting the fully exstended ram with a bar through the hole seems to have removed the crud/rust that as suggested must have wedged it in the seal. No scratches on the ram so hopefully got away with it. Now to clean out the shite from the resevoir, and try and flush out the ram with new oil. Presume water is moisture that  built up on the inside over the years, because its all sealed up externally. 

Edited July 20, 2024 by Mark