Sweating Cohline hoses

[paulsco]

My restoration has been long and drawn out, but I thought I was finally finished at the end of last year.
I had rebuilt the brakes and the clutch system and had installed new reservoirs and rubber hoses.
The clutch hydraulic system has been filled and bled some years back, but I have only recently filled up the brake system with fluid.
All seemed fine at first, but the seals in the servo appear to have a problem and the driver side (RHD) brake reservoir is emptying and the servo one has overflowed, spilling fluid down the bulkhead.

As if this wasn’t bad enough, I have noticed that both the hose from the clutch and brake reservoirs and the hose from the reservoir to the servo are sweating fluid.
I have also noticed that the clutch fluid is darker than the more recent brake fluid.

I have concluded from this that the brake hoses may be deteriorating internally. The reservoirs look fine.

I noted from the forum that it is necessary to get Cohline brake hoses as anything else weeps.
Ah, I thought, I must have bought the wrong hoses all those years ago, so ordered Cohline hoses from Merlin Motor Sport.

I have been looking back through some old invoices and noticed to my horror that the ones I have been using are Cohline (2337), which I bought from Merlin Motor Sport some years ago!

Has anybody else bought Cohline hoses and had a similar problem?

Thanks,
Paul

[mgcjag]

Hi Paul...does your hose say cohlin on it.....did they supply the wrong hose....Steve

[Series1 Stu]

Hi Paul

This is interesting because I have just noticed the same problem.

I bought Cohline for my car and fitted it on all 3 reservoirs (Series 1 3.8 Kelsey Hayes set up).

Now it appears that the clutch flexible pipe is sweating, although the brake flexible pipes appear fine.

I have my pedal box dismantled at the moment so may replace it all but I did question whether I'd actually got the Cohline, despite it being printed on the pipe.

Regards

[cactusman]

It should have 'Cohline 2337 stencilled into the outside...Cohline make many grades of tube ....possibly you got the wrong one by mistake.

Other possibility is that the tube is not sweating but the reservoir has cracked at the bottom and fluid is gradually seeping out and flowing down the outside of the tube. I've had three reproduction reservoirs (round 3.8) split where the outlet joins the base. It looks as though the tube is sweating but it is not....There are several threads relating to the reproduction revervoirs. Afraid a lot that have been sold by all the usually suppliers over recent times have been substandard and not fit for purpose although things may have improved.....

[rswaffie]

[paulsco]

Hi All,
Thank you for your input.
After posting my question, I wondered if it was even possible for all of the hoses to be sweating at the same time. After all, the clutch one had been in use for considerably longer than the brakes.

I had another look today and I can see no sign that the reservoirs are split or leaking.

However, I have established that the hoses are Cohline , but they are Cohline 2190!

https://www.merlinmotorsport.co.uk/p/ru ... -2190-0615

Which appears to be fuel line.

I have checked my invoice again and the order was for 2337, so the wrong hose was supplied.
The new hose is however correct.

A costly mistake not checking my orders








Thanks again,

Paul

[Series1 Stu]

It should have 'Cohline 2337 stencilled into the outside...Cohline make many grades of tube ....possibly you got the wrong one by mistake.

Other possibility is that the tube is not sweating but the reservoir has cracked at the bottom and fluid is gradually seeping out and flowing down the outside of the tube.

For completeness, I did use Cohline 2337 and, you are correct, it was a defective "new" reservoir.

I have now reconditioned my original reservoirs and will be re-fitting them this weekend.

Regards

[cactusman]

It was another defective new reservoir.....hopefully the usual suppliers are more than slightly aware that those sold hitherto are poorly made and unfit for any purpose let alone something as critical as a brake system. They need to be manufactured as a single seamless bottle and not as two half sections badly welded together.....it is possible!

[288gto]

It was another defective new reservoir.....hopefully the usual suppliers are more than slightly aware that those sold hitherto are poorly made and unfit for any purpose let alone something as critical as a brake system. They need to be manufactured as a single seamless bottle and not as two half sections badly welded together.....it is possible!

From Julian Barratt himself back in June 2019 following the Barratts feedback day....

I note there is a Sovy bottle thread elsewhere on the forum - my recollection of this is that the spec was changed some years ago to help reduce the possibility of any failures - but my colleague Paul is looking into this as i write.
Many thanks again to those who took the time to come over and i will report back in due course...

And from the Barratts Manifesto published a few days later...

Many thanks again for those who took the time to come and see us and share their views a couple of weeks ago........... a few of the key take-aways that I will be taking away from the day and working on during the months to come.

1. Give customers more feedback on issues that have been resolved/addressed. There was a feeling that issues can drop into a black hole of no feedback even when they may have been resolved or addressed from our side

Out of interest, did Barratts go back and look at the manufacturing methods used on these and what was the outcome? Perhaps I missed it somewhere?


Simon

[cactusman]

All the ones I have ever seen for sale have been moulded as two half sections and then welded together....this may have been how the originals were made....but I have had three copies from different suppliers fail over the past five years....all three failures were the weld seam splitting just below or at the sharp bend at the bottom where the outlet is. So unreliable are they I have two spare bottles in stock for a rapid swap should a split happen.
Whether or not the originals were moulded in two bits and joined seems irrelevant. It is perfectly possible to blow mould as a one piece bottle removing the seam weakness entirely...be interested to hear it SNGB have indeed managed to make such a bottle as that is the solution....

[mgcjag]

Please see post 70 http://forum.etypeuk.com/viewtopic.php? ... f9#p131189

[288gto]

Cheers Steve,

The only reason I ask is that I've been holding back ordering some from Barratts until they were 100% sure they had fixed the problem. I cleaned my old ones up pretty well but they are still slightly yellow and over 50 years old..

I wonder whether it would be worth Julian updating the Barratts Users Group thread about issues they have resolved or are still looking into so that the updates don't get lost or missed. Maybe just a link that ties the updates together?

I know what you're going to say......concentrate on getting the damn thing on the road. I had to go and check my hoses to make sure they are 2337.


Simon

[mgcjag]

No mate wouldnt say that at all.....i dont know how you will cope with the dust dirt and stone chips

[JulianBarratt]

Hi All,
I have updated the Barratt User Group for this one as it seems that my updates on other threads are not cohesive and will aim to do that for the future also. Thanks Steve for pointing people in the right direction to my response on this specific issue above also.

http://forum.etypeuk.com/viewtopic.php? ... 5e#p140480

number #131.

Feedback always welcome and if the "new" failure above is from a recent purchase from us, then i would be interested to hear.

[Series1 Stu]

If its my failure you mean Julian then no. They were bought a good while back.

Regards

[paulsco]

Is this a problem confined to the round reservoirs as most of comments appear to be from people with 3.8’s?

My reservoirs were bought from SNG several years ago 2015??

They are the square reservoirs and have a substantial metal tube support for the hose spout.

My reservoirs are fine and I can find no evidence of splitting.

My problem was with the hoses.

Paul