Saracen driver's hatch hydraulics and vision block

[trophy160]

I've got around to the last of the cosmetic improvements to my Saracen, namely the drivers hatch. The hydraulics have never fully lifted the inner flap presumably due to a lack of fluid. There are also signs of historic hydraulic leakage near the ram. So I have several questions:

 

1. What hydraulic fluid should I use?

2. Where is the filler, there are three allen bolts on the top of the pump/reservoir, I have unscrewed the one on the left in the photo and the one near the handle, is this where I fill from?

3. Is there any need to bleed the system, if so from where?

4. With regard the ram, it may be that it would benefit from a change of seal(s), is this possible. There is what appears to be a non removable circlip at the top, should it be possible to strip the ram?

 

I also managed to remove the centre vision block which was knackered (I have a replacement one to fit). Since this was rusted in, the technique I used was to smash each of the 8 layers of glass in turn and once all the glass was removed I was able to collapse the outer frame of the vision block and remove it. In front of the vision block set into the armour is a separate piece of glass, I was very please that I had not broken this whilst smashing my way through the vision block.

Much to my annoyance, when I went back to the vehicle a few days later a crack had appeared down the middle of this piece of glass.

 

Does anyone know if this piece of glass is available, I have tried Richard Banister but he can't help

 

Nic

[fv1609]

Nic it looks to be the same as in a Mk 2 Pig. I have the EMER with drawings of pump & ram if you get really stuck.

 

The fluid is OM-13

 

There are three Allen screws on the top of the pump, is there not a hexagonal headed screw on the top in lower right hand corner hidden in the photo by the pump handle? That is the filler plug.

 

PS You can dismantle the ram & replace the four O rings by removing the "internal circlip".

Edited April 20, 2016 by fv1609
PS

[Starfire]

Yep, OM13 is what you should use (ISO 12 hydraulic fluid), but auto trans fluid will work. The filler should be the bold that is sticking up under the handle - careful though, if you overfill it, it'll spray out from the overflow.

[trophy160]

OK I was being particularly thick yesterday, I shan't bore you with my excuses.

 

So I have dismantled the ram and can see the O rings, I am reluctant to remove them to take measurements in case they break and I can't get any replacements, so the next question perhaps for Clive is do you know what their dimensions are/where I might get replacements from?

 

Nic

[fv1609]

Nic I suppose if the rings were that vulnerable then they are not worth retaining. Perhaps buy an O ring selection box & see what you can match & then hunt in earnest for any remaining. (If stuck I have a good range of O rings that I got from a scrapyard as they had no value as they were only interested in metal).

 

Below is a picture of the ram circa 1973. Not a lot of help I'm afraid.

 

 

The pump & ram were upgraded in 1975 there are lots of NSNs but none of the component internals.

 

2590-99-821-8227 Pump, hydraulic

2590-99-821-7966 Ram, retraction

[trophy160]

Thanks for the drawing Clive

[fv1609]

I've got an exploded diagram of the pump if you need it.

[trophy160]

I think the pump is OK thanks Clive