Humber front hatch fluid

[webley455]

Afternoon all

my Pig has had a fluid seeping from the Drivers hatch hydraulics,  it has now stopped seeping but the hatch only opens halfway.

i am going to remove the piston and clean / replace the seals but is there any particular hydraulic fluid I should use to refill?

Ta

Norman

[fv1609]

Norman the fluid will be defined in Army Code No.13068 Servicing Schedule, Humber 1 Ton. Jan.1974 (Revised 1990) but I think it is OM-13

I think I should be able to tell you the part numbers for the seals as I think they are mentioned in the EMERs covering the vision blocks.

You may well know this, but it is widely believed that the vision blocks were an integral part of the Op Bracelet upgrade (ie to Mk 2). But that is not so, the hydraulic vision blocks were a later upgrade. The Mk 2  originally used the existing visors with Periscopes No.17 Mk 1 or Mk 3 (don't know what was wrong with Mk 2!) which were then overlaid with a large steel sheet with a side flange & of course an 'ole for the visor.

[Richard Farrant]

As Clive says, OM13 is the army designation for the visor oil. This will mean little to an oil supplier, but it is in facthydraulic oil to the grade of ISO 10 that you need and it is often hard to find in small quantities, but just seen this link to the grade in 1 litre bottles:

https://www.ebay.co.uk/i/111658331319?chn=ps

regards, Richard

[Degsy]

If you have difficulty obtaining ISO10 try m/cycle dealers, that's where I used to get it.

[webley455]

Thanks for that info, much appreciated.

is there a bleed nipple anywhere or is there anything else I need to know before I attempt the fix?

thanks again 

Norman

[fv1609]

Can't remember a bleed nipple but don't you have the complete assembly?

I have the installation EMER for them but not easily accessible at the moment, maybe able to dig it out at the weekend.

[webley455]

I do have the complete assembly, as there is no bleed nipple I assume it bleeds itself through operation ( like power steering?)

the air in the system is preventing the hatch from fully raising, I am having to peer through a smaller opening and apart from giving me neck ache the Pig is going through our Jersey DVS next month for its full inspection prior to its registration.  Restricted visibility would probably mean a fail ☹️

[Richard Farrant]

1 hour ago, webley455 said:

I do have the complete assembly, as there is no bleed nipple I assume it bleeds itself through operation ( like power steering?)

the air in the system is preventing the hatch from fully raising, I am having to peer through a smaller opening and apart from giving me neck ache the Pig is going through our Jersey DVS next month for its full inspection prior to its registration.  Restricted visibility would probably mean a fail ☹️

It may not be opening far enough becuase the oil level is low. You did say you were looking for oil.

[Peakrec]

Light hydraulic oil om10 is fine, do NOT use brake fluid as that will rot the seals. Fill the reservoir  and slighty undo the small flexible pipe at the ram, use the hand pump and expel any air. Tighten when fluid seen. Then the ram should move. Make sure pump works on both strokes. There is a filter in the reservoir clean as can get blocked.

[webley455]

Excellent, thank you very much, I will hopefully get it sorted this weekend 🙂

 

[webley455]

Oil procured, hatch now working, I still need to source replacement seals as it still seeps.  However, I can now drive without difficulty 🙂

many thanks for advice given

Norman

[Peakrec]

When you remove the cylinder, there is a small grub screw holding the pin (Located between the cylinders). Remove that. Tap out the pin,  careful not to mushroom the end.  Will need a stout piece of wood to hold the hatch open to help removal of the cylinder as a tight fit. Leave the pump lock off valve open so fluid returns to the reservoir and not all over the instruments. Will still need to cover though.