Jump to content

What do you use instead of OM13?


Recommended Posts

At the moment, I'm using Clarkes SAE30 oil designed for compressors and garden engines. I read it was a decent replacement for OM13 on some website a while back. But is it any good? What is the best stuff to use? Castrol 15/30w part synthetic? I've read through the various threads here and to be honest I got even more confused lol. Anyways, I'm going to clean out the system and fill it up so would rather use the best stuff.

Link to comment
Share on other sites

OM13 is ISO 12, ISO 10 & 15 is easily available... I use ISO 10 in the Fox... (from Rye Oils)

 

You're going to need a good few gallons to flush that lot out...

 

Richard Notton wrote....

OM-13 - This stuff still causes a heap of hand wringing, its just ISO 12 or 12cSt hydraulic oil and militarily has a weeny tad of stearic acid added that private owners can wholly ignore. Hydraulic oils change viscosity hugely with temperature and OM 13 is no exception, especially as no Viscosity Index (hydraulic term for "multigrade") improvers (VI) are allowed. As you can see from the chart referenced above, the spec is always at 40ºC and the cold oil is far thicker than at the reference temp. Hydraulic circuits are extremely tolerant (they have to be) and a lot of the mil fittings are commercial parts anyway intended for the middle of the road, to be found in every JCB, ISO 32. You can get Shell Tellus 15 and that's easily close enough but I do have 32 in everything except the very fine manual controls. Lets face it, the systems just think its a bit colder out than it really is and even OM13 is treacle at -25ºC as the spec says so (1250cSt):

http://www.dstan.mod.uk/data/91/044/00000100.pdf

 

 

Edited by Marmite!!
Link to comment
Share on other sites

Val,

 

Where are you putting the SAE30? In the engine is fine, in the gearbox is ok, anywhere else and I think you may need to read the manual again!

 

Chris

 

 

That's why I was saying he's going to need a hell of a lot of OM13 to flush that lot out if he's put it in the brakes....

Link to comment
Share on other sites

The SAE 30 is going in the engine bay, left hand side from the front, where it is marked OM13, the manual diagram seems to say this is the right place.

 

Have I broked it?

 

Quite possibly, and this may explain why the hose burst. SAE30 is not equivalent to OM13 - ISO10 hydraulic fluid is. SAE30 is OMD110, which is engine oil.

 

Read through this, it's not 100% relevant but might help... http://www.users.zetnet.co.uk/lsm/dhmg/fer-oils.html

 

Chris

Link to comment
Share on other sites

 

Not sure what SAE30 will do to the braking system
OM13 and SAE30 are both mineral oils, so no real harm done in this case, except that the 30 is too thick a viscosity. It should not have got to the brake cylinders so far, so if all the oil is purged through the blown hose, that will get rid of a lot of it, problem is that it has circulated the steering system.By the time the system is refilled with ISO 10 grade hyd. oil it should have thinned out.When you refill the reservoir, before you start the engine, release the bleeder screw on top of hyd. pump and wait for the oil to come out of it, tighten up and then run. If you do not do this, there is danger of the pump running dry due to an airlock.
Link to comment
Share on other sites

Quite possibly, and this may explain why the hose burst. SAE30 is not equivalent to OM13 - ISO10 hydraulic fluid is. SAE30 is OMD110, which is engine oil.

 

Read through this, it's not 100% relevant but might help... http://www.users.zetnet.co.uk/lsm/dhmg/fer-oils.html

 

Chris

 

The Clarks stuff is an awful lot thinner than any engine oil I've seen, bugger though. How do I get it all out? The SAE30 stuff has been in there for a year and working fine up until I topped it up the other day :(

Link to comment
Share on other sites

The Clarks stuff is an awful lot thinner than any engine oil I've seen, bugger though. How do I get it all out? The SAE30 stuff has been in there for a year and working fine up until I topped it up the other day :(

 

My eyes rather glazed over reading this thread as it isn't really my scene. The Clarks, is this what people have recommended as an OM13 substitute? If so, it most certainly IS an awful lot thinner than any engine oil you've ever seen, because OM13 is NOT engine oil. Among other things it is used as lightweight gun-oil where, in civvy street, I used to use All-In-One.

 

I do remember on my gunnery course being blindfolded and having to identify OM13, OMD75 and I think probably OEP220 so that I could service Scorpion weapon systems and not use the wrong oil.

Link to comment
Share on other sites

OM13 is a very light oil, it's almost like water. SAE30 is thicker, but still thinner than a modern engine oil.

 

Val, I think you're going to need to check every lubricant you've used and make sure it's suitable. Any which are wrong will need a thorough flushing through, or you could just park the Saracen up for a few years and wait for it all to drain out!

 

Chris

Link to comment
Share on other sites

How much is the Morris stuff?

 

How do I flush the SAE30 from the system?

 

 

Not bought a drum lately, but would think with oil prices rising, not much different to the one you found.

 

To drain system, drain off brake system from you damaged hose, the motor oil will not have got very far through brake system as the oil does not circulate around it only pressurised from twin control valve. The steering system circualtes. Take top of reservoir and remove filter, pump out the tank and refill, this will thin out any remainiing 30 in the system. You will have to bleed all the brakes and purge air out of steering, this is done by getting front four wheels off the ground and working steering lock to lock.

 

Don't forget what I said about bleeding air from pump, before starting engine. You really should get hold of the workshop manuals for the Saracen, they are known as EMER, covering all levels of maintenance and repair.

Link to comment
Share on other sites

  • 7 months later...

Really good advice above and very relevant to my very cautious renovation of my Saracen. Can I add another question, re OM13 equivalents and the jungle of comparing ISO OM SAE etc

 

I have got LIC 10 ( Lic 10=ISO VG 32 ) see:

 

Looking at the Richard Norton's quote: "As you can see from the chart referenced above, the spec is always at 40ºC and the cold oil is far thicker than at the reference temp. Hydraulic circuits are extremely tolerant (they have to be) and a lot of the mil fittings are commercial parts anyway intended for the middle of the road, to be found in every JCB, ISO 32"

 

This looks about right. My dip stick is just touching the top of the hydraulic oil so I am looking at topping up. LIC10 (depending on how I interpret the above) appears to be spot on.

 

Is anybody going to say - don't.

 

Simon

Link to comment
Share on other sites

Can I add another question, re OM13 equivalents and the jungle of comparing ISO OM SAE etc

 

I have got LIC 10 ( Lic 10=ISO VG 32 ) see:

 

 

 

 

Hi Simon,

 

You cannot compare ISO grades against SAE. ISO is used for hydraulic type fluids, SAE is used for engine and gear oils.

 

OM13 is equivalent to ISO10. Comma LIC10 is an ISO grade of 32 which is the common hydraulic grade for plant equipment, etc. The higher the number the thicker the viscosity. The difference in grades is done for a reason, otherwise the military would have standardised with the 32 grade, which was also widely used in their plant. Best to keep with the specified grade, then if any problems occur, you know they are not related to the incorrect fluid.

Edited by Richard Farrant
Link to comment
Share on other sites

Thanks Richard

 

Shows what my local garage knows, I asked if they had any ISO10 oil and I left with LC10 - clearly not ISO10. It'll stay in its carton.

 

I must admit it did look a lot more viscous than I was expecting!

 

I'm in Lenham (I think you're in Ashford?) is there anywhere local that you would recommend for ISO10?

 

regards

 

Simon

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...