Sovy Failure

[288gto]

Hi
It’s in the Knowledgebase.

http://www.exisle.net/mb/index.php?/top ... after-all/

I did actually try this with partial success. They were definitely less yellow at the end of the process but not white like a new bottle. As mentioned above I considered slightly yellow bottles better than paint stripper all over my bulkhead. There are companies manufacturing reservoirs for race, rally and kit car applications that don't leak so clearly something is going wrong.

Simon

[ysmalkie]

Thanks Richard!

[mgcjag]

Well worth mentioning here (but dosnt solve the sovy problem).....and please lets not start a discussion here but dont forget the option of Silicone brake fluid.....it dosnt strip paint.....some of the top restorers use it and so have i for about 15 years with no problems.....Please start a new thread if you want to discuss or pm me and i will start one.....Steve

[ralphr1780]

Hi
It’s in the Knowledgebase.

http://www.exisle.net/mb/index.php?/top ... after-all/

I did actually try this with partial success. They were definitely less yellow at the end of the process but not white like a new bottle. As mentioned above I considered slightly yellow bottles better than paint stripper all over my bulkhead. There are companies manufacturing reservoirs for race, rally and kit car applications that don't leak so clearly something is going wrong.

Simon

After disastrous similar failures, I too have opted for cleaning the old bottles which are still holding well.
First pushed the filters out, then a bath in an ultrasonic cleaner, and onwards discretely in the family dishwasher. Result is absolutely satisfying, and in the engine bay they look in harmony with the rest.

[JulianBarratt]

To update on this one from our QC team:

Having reviewed the material specification with positive results, we can further advise that our long term test examples that have been in constant exposure to both clean and contaminated brake fluid, have not revealed any detrimental effects or resulted in any observed failure. In house destructive testing does not indicate any additional weakness other than that, that is inherent in the original design. The thin feed tube can all too easily suffer stress and consequential damage when be when the hose is attached – Detailed guidelines indicating the best installation techniques will now be included with these products as standard.

Additionally, we also now plan to sell these bottles with the hose and the clamp pre-fitted as an option.

We will, of course, be looking at any failed ones that come back to us to determine why these have failed and why we were not able to reproduce such a failure in our own testing. As some forum members may know, we did apply some significant changes to the spec of these bottles in recent years in terms of the thickness of the material used - this was further to customer feedback.

It is our plan to look at the possibility of a full redesign and retool of this product to see if we can make an improvement on the design - which is from the tooling we acquired when we purchased sovy 20+ years ago - but this will be subject to the usual commercial constraints.

I will update further in due course should there be any change on this.

[Heuer]

I just fitted a new replacement bottle and used red rubber grease on the spigot. The pipe pushed on with no resistance or stress to the bottle. May be worth including that in the instructions or provide a tiny packet of rubber grease; only a thin smear is required. The idea of pushing a short piece of Kunifer into the hose and shaping it to a constant radius would also help ensure there are no lateral forces on the spigot.

In my research I also found the original style 5/8" (15.88mm) clips C15886/5 are too big for the diameter of the currently supplied low pressure hose C18717 (13.5mm) and do not fully clamp to produce a seal - 1/2" (12.7mm) clips should be used. The original Girling 'yellow strip' hose was 5/8" but no longer available.




So do NOT use C15886/5 clips on the bottles as they will allow fluid to seep out. Maybe worth a warning with the bottle/hose instructions. Standard Jubilee clips or Cheney clips would work or use the smaller C15886/4 specified for securing the hose to the hydraulic pipes. Those C15886/4 clips (£0.62 ) are also 1/10th of the price of the C15886/5 clips (£5.88).

C15886/4 superceeds to C43599/8:

[rswaffie]

Great work Julian.
I’ll send mine back as per your PM, this is where it split, which ties in with the hose fitting/positioning root cause.

The split started at the base of the spigot ....



And continued across the base.

[Whitact]

Hi Julian,
Thanks for the quick, thorough and positive response to us all.
Quite different to the terse response from the vendor of my failed unit a while ago.
I think the recent forum visit demonstrated very well the challenges SNGB face as manufacturer and vendor of so many different parts to a market which has moved on a long way in the decades since those parts were first produced. Your response reflects the substantial investment and commitment SNGB have made in addressing those challenges.
Cheers

[rswaffie]

[Heuer]

It does show SNGB need to take a synergistic approach in that you can't look at one item in isolation but also consider the other intervening variables. In this case the bottle, the hose and the clip all need to work together. One could also add the bottle bracket, filler cap and pipe.

[cactusman]

Had I made it to the user group this was an issue I planned to raise as I have had three fail all at the bottom where the outlet comes down. I am not sure how the originals were made but to me the solution is a bottle blow moulded in one unit with no welded seam. I am not a plastic moulding expert but I see no reason why it should not be possible. Good to see SNGB are On the case

[mgcjag]

Just for info...the bottles are blow moulded and not made in two parts and weded together....this was confirmed by SNG at their Sale day today...Steve

[Heuer]

I don't think there is a welded seam, just the line between two halves of the mould. I am guessing but I think they are blow moulded.

To be fair to SNGB they have no control over how these are fitted. If the pipe is too long it will stress the spigot when the bottle is clamped in place. Ideally the hose would be cut to a length that prevents any excess being taken up by bending of the spigot.

My process now is:

1. With a dab of red rubber grease push the hose onto the spigot
2. Attach the bottle to the bracket and loosely tighten
3. Put two clamps on the hose and secure the top one
4. With red rubber grease on the copper pipe slide the hose on and dress so there is minimal stress on the bottle. The grease makes this easy.
5. Tighten lower clip, tighten upper clip, tighten bottle bracket
6. Ensure the clips are the correct size for the hose. If in doubt check tightness with a spare piece of hose and pipe
7. Check the supplied hose is of the correct type. This subject is fully detailed elsewhere on the Forum. Using the incorrect hose may lead to it 'sweating' brake fluid onto the frame. http://forum.etypeuk.com/viewtopic.php?p=15015#p15015

This build sequence seems counter intuitive as it would seem easier to put the bottle on the hose last.

[cactusman]

Sorry...don't believe they are made in one piece. Millions of blow moulded bottles are made daily for e.g lemonade bottles....no seam. look at any plastic milk carton and you will see no seam....There is no reason for a seam....in fact a genuinely blow moulded bottle won't have a visible seam.......unless they are moulded in two parts and then bonded together....I appreciate that all the suppliers get their bottles from the same place....and they may well be good that they are blow moulded whole....but to me the evidence points very much to this being untrue.

[Heuer]

Easy to confirm - if it is blow moulded there will be no seam on the inside. The seam on the outside is where the two halves of the mould meet. If it is made in two parts there will be a seam on the inside and outside.

The seam on the outside is because the tooling is old and the moulds do not mate perfectly. It should not be a line of weakness though.

[mgcjag]

Hi Julian.....you have worked close with SNG before......both Paul Domican( Group ops dir) & Peter Stant ( Head Tech) confirmed that the bottles are one piece moulded......please use your contacts and let us know what you find out....Steve

[cactusman]

Indeed....the ones that failed definitely had a seam....more a visible crevice...inside....after the last failure I bought three! I have just looked at one of my spares....brand new in bag....it has a visible seam inside... So to me it has either been made in two halves and then bonded together...or the mould edges are extremely poor...either way the manufacturing process generates an inherent weakness and this is then exacerbated by pressing the aluminium ferrule and filter....failure of the bottle is safety critical and also removes paint if you have glycol fluid...Hopefully Julian and the SNGB team can talk to the supplier and a solution can be found.

[Heuer]

The (square) bottles on my OTS have been there for 20 years without problem. Failures are associated with wrong or poor installation IMHO and there is an easy way to check your bottles. Undo the fixing bracket and see if the bottle moves upwards - if it does them the hose is too long and will be putting constant pressure on the bottle base/spigot which will ultimately lead to failure. This is my FHC bottle loose in the holder. You can see it drops about 1/8th of an inch below the locating hole when set free but is otherwise self supporting.


When I released the failed bottle it rose upwards and the 'dot' was above the bracket by 1/2" (no photos unfortunately) so when fitting the new bottle I dressed the hose so it supported the bottle at the correct height as can be seen above.

We have to take some responsibility for best practice and not lay it on the supplier when failures happen unless there is outright proof of manufacturing error. I do think it would be good practice for SNGB to include fitting instructions with such safety related parts along with warnings about the effects of poor installation. Whether anyone will read them is another matter

[ysmalkie]

I had 3 that were:
- split at the seam (hose end) on arrival - hardly an assembly fault
- split on the seam at the bottom,
- leaking near mounting, either due to poor mounting or due to fatigue.

In the last 2 cases they were not leaking after the installation, they were however leaking after a (short) period of time.

I do not believe Julian these are simply mounting issues, I believe these are issues do to vibrations that cause them to brake.

Unfortunately, it's difficult to remove the vibrations from the engine....

Tadek

[cactusman]

Sorry David. It is not an install issue but a manufacturing issue. Lemonade bottles are under high pressure from the contents, are jangled and bashed about during transit, have much thinner walls than the sovy copies and do not fail. Brake fluid bottles are secured to the bulkhead, are not under pressure and would not fail were they properly manufactured. I am with tadek .