Hydraulic hand pump – air release? What are these screws?

[ell81Participant @ell81]

OK. So I have bought a hydraulic hand pump at auction. It sounds hollow, so obviously I need to fill it with hydraulic oil.

I googled that and know how to do it.

But….I have to bleed the air out of the system which makes me wonder – how does the air bleed out of it, and when it does, why doesn’t the hydraulic oil bleed out of it too?

Also, this pump I have, has 2 identical screws in it, where the arrows are in the pic, with rubber o rings, I assume to stop hydraulic oil leaking out of them. What are they for?

Also, one more question – what is some appropriate and cheap hydraulic oil to use for it? Thanks.

Thanks in advance.

[noel shelleyParticipant @noelshelley55608]

It’s an ex hire unit may be from a pipe bender, the colour minds me that its an Enerpac unit. Hydraulic oil SAE 10 or ISO32 If your near me I can give you a fill, It is available from motor factors and good bearing and transmission specialists, or  use an ordinary power steering fluid, mineral not synthetic. One of the valves (screws ) will be the relief set at 10,000 psi, YES 10,000 ! The threads in the outlet will be either 1/4 or 3/8 BSP and from the picture the coupling looks as though it is an iso A, may be 3/8″. Do you have a cylinder and hose for it ? To be able to bleed it you need to just expel the air, if you use a spring return cylinder then just pump it up a short way and then release, the air will be returned  to the reservoir. Need more info just ask. Noel.

[howardbParticipant @howardb]

Can’t help with what the screws are for, but just go to a car accessory store and ask for jack oil or ISO 32 hydraulic oil.

eg –  https://www.wilcodirect.co.uk/product/hydraulic-fluid/comma-jack-oil-500ml-gc-0177/GC-0177

[ell81Participant @ell81]

Thanks guys. And @Noel  I thought all Enerpac stuff was yellow? Or did they used to be red?

[noel shelleyParticipant @noelshelley55608]

OH DEAR, I thought it was a yellowy green – but I’m colour blind, may be it’s worse than I thought ! Noel.

[Martin ConnellyParticipant @martinconnelly55370]

We bled them with a jack on a hose. Tilt the pump with the outlet down a bit relative to the other end of the pump. make sure the hose slopes down to the jack and the jack is the lowest point. Pump up the jack and then release the pressure and push the jack back in. Repeat. When you stop hearing and feeling bubbles moving through the system it is fully bled.

Martin C

[not done it yetParticipant @notdoneityet]

Good luck with your ‘auction’ pump.

I am always expecting problems with items bought at auction (no warranty).  I would be expecting to likely need to source new seals for that item.  But, if cheap enough, maybe worth a punt….🙂

[noel shelleyParticipant @noelshelley55608]

I have a unit not unlike this but with a built in control valve allowing double acting and a double acting cylinder so it can push or pull with a force of about 10 tons – handy for all sorts of jobs. The way industry seems to work specialist tooling is brought in, used (or not ) and then sold off at a fraction of the new price when the job is finished. Numerous gear I have has been acquired this way. Noel.

[not done it yet]

On not done it yet Said:

Good luck with your ‘auction’ pump.

I am always expecting problems with items bought at auction (no warranty).  I would be expecting to likely need to source new seals for that item.  But, if cheap enough, maybe worth a punt….🙂

I’m a pessimist too!  Why has someone drained the oil?  I guess it’s misbehaving and the owner only got as far as draining the oil before finding spares are too costly or not available.  Or maybe they found bad damage inside.  With luck, they just ran out of enthusiasm and it’s a cheap easy fix.

I have several items awaiting repair, which someone with time and energy could easily bring back from the dead. Won’t be me – I’m knackered!

🙁

Dave

 

[DiogenesParticipant @diogenes]

I’ve seen some great stuff go from dispersals and retirement auctions.. ..and I’ve seen some truly heart-breaking stuff left behind for the scrap-man..

 

 

[Author]

Posts