Hydraulic Lift Table Help

[Terryb]

Hi guy’s, not sure if this is place to ask for help/advice, but I’m out of idea’s.

The priming pump on my Hydraulic Bike lift table is leaking badly. I’ve taken it apart and purchased replacement seals. Ok, I can assemble the 12mm ID seal in the pump body entrance, but I’m finding it impossible to push the pump shaft in. I’ve checked the seal ID is correct, but I’m afraid that if I is force the seal will get damaged. Any idea’s?

[dave55]

Hi Terry , are you sure that seal came out that way up ? looks upside down to me

[Billybream]

Looks like a neck or nose seal, and appears the wrong way around as Dave states
It seals the rod but acts a scaper also.

[muskrat]

G'day Terry.
+1 ^^^^^
Cheers

[Terryb]

I’m sure that’s the correct orientation. The recess just inside the cylinder has a lip, but thinking about you may be right. I’m indisposed at the moment, so I’ll check and get back to you. Thanks guy’s 👍

[RDfella]

Without seeing the other side of the seal, not so sure it's wrong way round, but can you fit the seal in the tube first and and the ram after? Just a suggestion - there's so many different types of hydraulic ram seal and retaining mechanism.

[BSA_54A10]

What retains that seal ?
if there is a circlip then it would be wrong way up
If it just squashes into the hole or has a wire retainer then it is wrong way up

[Terryb]

Hi Guys, still not in a fit state to resume fitting a new seal. Firstly the new one is being looked after by the GPO. Secondly, still Tom & Dick.

The ram has a rectangular recess about 3mm inside, like an ‘O’ ring grove, but rectangular. So I guess the seal can fit either way. When I fitted it back as show in the photo, I couldn’t push the ram piston in. Thinking about what you guys have said, by rotating it should make it easier to assemble the piston.

When I get the new seal and get back to getting about, I’ll try again. So Merry Christmas All and I’ll speak to you in the new year

 

[Swarfcut]

  That seal should not affect the movement of the piston in the cylinder. Surely that is only the external dust seal? A little lubricant on the chromed ram and the seal should slide easily.

 Swarfy.

[Terryb]

Hi All, hope you all had a great Christmas and getting back into your Workshops/ Sheds for a bit of pre-riding maintenance.

OK the new seal has arrived and I need a bit of advice as to the orientation. I've asked the supplier, but no response from them as yet.

Attached is the new seal, can someone advise which way I need to install it please. From the comments I received before regarding the old one I'm guessing the conical end should face out.

[muskrat]

G'day Terry.
I would say yes the "conical" side out. That would act as a dust seal. It should have one or two lips behind it facing the other direction.
Cheers

[Terryb]

Thanks Muskrat for the help. Another question, how the bloody hell do you change out the O-ring and the nylon washer?

[Swarfcut]

 I've lost the plot here. This can only be a low tech style piston in an open ended cylinder for assembly, then capped off with some sort of ram support bushing  and finally  a dust seal to wipe the ram and keep oil in and dirt out. If the ram won't move, something is broke or if assembled the  release valve is still closed or the return blocked.

 Seal on the ram piston can be simple eg O ring, complex as in spiral wound segments, but in any case how it comes apart is self evident once you have it down to the basic assemblies.

 Having risked pain and maim with a  Hydraulic Chinese Log Splitter...containing an unexpected big bastard of a return spring that took some getting back in, I'd first suggest a YouTube search on hydraulic rams and their workings. Simple enough in principle, but care still needed to avoid injury on some of the bigger stuff. More pictures of the rest of the pump and ram would help. Are we talking the same seal? The blue one pictured is distinctly different from the original black one, being thicker and with a different edge profile.

 Swarfy.