Oil Pipe, Split Nut.

Soenvious

Soenvious

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Changing the oil, I noticed the dreaded tell-tale crack in the large brass nut connecting to the oil tank. Obviously it's got to be an immediate fix. The question is do I buy the Hills Eng. split nut, or go for a second hand replacement oil pipe, or buy a new oil pipe? The split nut option seems favourite, and involves less work but is it a permanent fix?
 
mjheathcote

mjheathcote

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Would a jubilee clip tightened around an existing non split nut be a good safety measure?
Would look like it had been fitted as a bodge repair to a split nut though!
 
Zep

Zep

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To my understanding the nut splits because it is incorrectly used to drain the oil and then over tightened. If it splits it doesn’t fail catastrophically it just weeps oil. So I doubt a jubilee clip would help.
 
safrane

safrane

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Except for Loz's car that failed catastrophically dumped the contents on the garage forecourt.

Mines been done as it had micro cracks when treated to a dye check. Has full history by MD and specialists who always showed me photos of the oil change using the correct method... so I remain unconvinced its down to the above Zep... but happy to be proved wrong.

I was told it was down to two types of metal at the join and heating/cooling cycles being a source of stress.
 
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Soenvious

Soenvious

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129
Managed to remove the threaded nipple that is the other half of the connection to the nut. Pictures show the crack in the brass connecting nut and damage to the threaded nipple. The nipple damage looks more like electrolytic corrosion rather than mechanical damage. If so, this could be a hidden issue on other cars with this set up.
 

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Zep

Zep

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safrane said:
Except for Loz's car that failed catastrophically dumped the contents on the garage forecourt.

Mines been done as it had micro cracks when treated to a dye check. Has full history by MD and specialists who always showed me photos of the oil change using the correct method... so I remain unconvinced its down to the above Zep... but happy to be proved wrong.

I was told it was down to two types of metal at the join and heating/cooling cycles being a source of stress.
Click to expand...

Fair enough, I wasn’t aware of that. In that case a clip would certainly slow down, but not prevent a failure.
 
dgmx5

dgmx5

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Having just had the oil changed on Thursday, with thankfully no issue reported, I missed the chance to do this but at £100ish for the Hill split nut is this seen as a worthwhile preventative measure rather than await catastrophic failure?
 
Soenvious

Soenvious

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mjheathcote said:
Would a jubilee clip tightened around an existing non split nut be a good safety measure?
Would look like it had been fitted as a bodge repair to a split nut though!
Click to expand...
Considering the nut and pipework are on the suction side of the pump, then the connection should not be under pressure. A piece of rubber hose and two jubilee clips should sort it.:confused: (joking). It looks a bit over-engineered, unusual for Italian engineering.
 
midlifecrisis

midlifecrisis

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16,194
mjheathcote said:
Would a jubilee clip tightened around an existing non split nut be a good safety measure?
Would look like it had been fitted as a bodge repair to a split nut though!
Click to expand...
No!
Just cut the old nut off, fit the split nut. Job done.
The issue is that the old nut suffered from dissimilar metal corrosion and that mechanics tend to use this nut to empty the sump and not the sump plug. Extra wear on the nut resulting in its failure.
 
mjheathcote

mjheathcote

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midlifecrisis said:
No!
Just cut the old nut off, fit the split nut. Job done.
The issue is that the old nut suffered from dissimilar metal corrosion and that mechanics tend to use this nut to empty the sump and not the sump plug. Extra wear on the nut resulting in its failure.
Click to expand...

I'm not saying as a repair, but to stop the nut failing apart if it decides to split in the future to prevent then a catastrophic failure.
Or are we saying we should all fit the Hills nut now?
 
Zep

Zep

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If I still had my car, I would be considering it.

This is a failed nut, following removal, there are hairline cracks around the inside edge of the nut, which to me suggests over tightening. There is no evidence of corrosion.

80519

The end of the pipe has an “olive” shape which is a standard socket type hydraulic connection, it is designed to the majority of the sealing, the nut is just there to hold it in place.

80518

The Mav style replacement (as adopted by Hills) is sturdier, but only by virtue of needing to be to allow it to be installed in two peices.

80520

Do I still think it is due to over tightening? Yes. Once the cracks have formed, over time they will propagate and eventually fail. This is likely to take a long, long time. So for me, if you are minded to, replace when doing an oil change. Otherwise, make sure it is inspected at every annual oil change. It is always important to check your nuts!
 
redsonnylee

redsonnylee

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1,549
As soon as I got my GS I had the split nut installed. Its an easy piece of preventative maintenance.
When I read about the repercussions of it failIng it was a no brainer.
 
Soenvious

Soenvious

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129
Oh well, just ordered the nut and threaded connector. A lovely Saturday afternoon shopping treat, not.:confused:
 
Mr S

Mr S

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821
I found it difficult to spend £100 on one nut, BUT, when it arrives you will see it is more than worth it in the finished product alone. Not to mention the actual issue of the nut failing and dumping your oil, probably whilst going down the road.
The nut that @Zep posted, is my old one. Glad he spotted the original was cracked. When we did an oil change, we Dremel'd the old one off, make sure you do it so the swarf goes away from the pipe, and block the end with rag etc. We also made sure we flushed the pipe as well as we could with brake cleaner just to make sure.
Fit and forget
 
conaero

conaero

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34,626
We are seeing the oil tank flange degrading and they are a pain to get.

we have our engineering guy on it to make some for us.

Watch this space...
 
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Soenvious

Soenvious

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129
Just cut the nut off in preparation for my new, shiny replacement.
Pic is both halves of the old nut, I'm sure I didn't do that much thread damage when unscrewing it:rolleyes:
 

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