Advice please, new brake hoses seem incorrect
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Post by: HJF » Sat Jul 18, 2020 9:40 am
Just had new brake hoses delivered for the Sprint.
The ends that fix to the chassis mounting tag, and then the hard brake line attaches to, do not seem correct. They are countersunk reducing the mating face area to the brakline flare.
When I offer up a flare there is minimal contact. My flares are fine as I have a professional quality flaring tool that gives good results.
Just feel that this is wrong; opinions please?.
Harry
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Post by: Craven » Sat Jul 18, 2020 12:36 pm
This might interest you.
4. A flare is a precision device: Never take a flare for granted. To seal brake lines against 2,000 psi takes some geometry. The male and female surfaces of the fitting are three to five degrees different between the sealing surfaces. In some cases, the flare is designed to crush or compress onto the surface to form a seal, and the tolerances can stack up quickly against you. An off-center cut combined with a poorly clamped line may look fine to the naked eye, but the connection may leak when it is compressed by the fitting.
4. A flare is a precision device: Never take a flare for granted. To seal brake lines against 2,000 psi takes some geometry. The male and female surfaces of the fitting are three to five degrees different between the sealing surfaces. In some cases, the flare is designed to crush or compress onto the surface to form a seal, and the tolerances can stack up quickly against you. An off-center cut combined with a poorly clamped line may look fine to the naked eye, but the connection may leak when it is compressed by the fitting.
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Post by: Elanman99 » Sat Jul 18, 2020 2:06 pm
That does look to be excessively de-burred/ countersunk compared to the fitting on the ends of the correct hoses.
Since the one shown is a SS(?) braided hose assembly it may not pretend to be a copy of the original, I would suggest checking with whoever supplied it and see if they confirm its usage on an Elan.
I see you show your location as 'North' so presumeit is somewhere above the equator. Did you get the hoses from a Lotus specilaist in the UK?
Ian
Since the one shown is a SS(?) braided hose assembly it may not pretend to be a copy of the original, I would suggest checking with whoever supplied it and see if they confirm its usage on an Elan.
I see you show your location as 'North' so presumeit is somewhere above the equator. Did you get the hoses from a Lotus specilaist in the UK?
Ian
68 Elan S4 DHC. Built in a weekend from a kit (just like the advert said)
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Post by: HJF » Sat Jul 18, 2020 2:59 pm
Elanman99 wrote:That does look to be excessively de-burred/ countersunk compared to the fitting on the ends of the correct hoses.
Since the one shown is a SS(?) braided hose assembly it may not pretend to be a copy of the original, I would suggest checking with whoever supplied it and see if they confirm its usage on an Elan.
I see you show your location as 'North' so presumeit is somewhere above the equator. Did you get the hoses from a Lotus specilaist in the UK?
Ian
Yes, a UK Lotus Specialist, advertised as being for a Sprint. I am wondering if it is a JIC form? Could see this sealing a concave seat say in a caliper, but doesn’t look secure enough sealing against a traditional Girling flare. Had a look on Matty’s online shop at a traditional version of this hose, see below, his looks correct to my eyes.
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Post by: elansprint » Sat Jul 18, 2020 6:07 pm
HJF you are correct in your final comment we used goodridge for updrating Stag braking and this is a universal end for concave/convex caliper which was good for us as we used Volvo and mazda calipers which were different to each other but we could use a common hose. Work perfectly never had a problem
Ian
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Post by: HJF » Mon Jul 20, 2020 11:20 am
Found out what this is now!
It is called a Dual Seat and seems to be a proprietary design and appears to be favoured by HEL. They say it will mate with any type of flare.
Really not happy using this to replace an existing hose with a standard convex mating face to existing flared pipe work. Don’t like the idea of having to deform the hard line flare to achieve a seal.
Found a screenshot on the web from a HEL instruction sheet. Found similar concerns to mine on other car forum.
It is called a Dual Seat and seems to be a proprietary design and appears to be favoured by HEL. They say it will mate with any type of flare.
Really not happy using this to replace an existing hose with a standard convex mating face to existing flared pipe work. Don’t like the idea of having to deform the hard line flare to achieve a seal.
Found a screenshot on the web from a HEL instruction sheet. Found similar concerns to mine on other car forum.
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Post by: Elanman99 » Mon Jul 20, 2020 11:36 am
I too am not impressed with this dual taper idea.
Having said that I am sure it will seal fine with a standard brake tube flare whether its steel or the copper alloy material. However if its a joint that is going to be undone and redone regularly, the reduced annular area might be less tolerant of re-sealing if the alignment of the two surfaces is not identical every time.
The hose end in your picture looks to be mechanical assembled on to the tube and braid, rather than the swaged type. Personally I am not in favour of SS braided brake lines on a road car because I have been told they suffer from corrosion. Not a problem on a race car with continuous inspection or if the car is only used a few times a year on dry roads.
Ian
Having said that I am sure it will seal fine with a standard brake tube flare whether its steel or the copper alloy material. However if its a joint that is going to be undone and redone regularly, the reduced annular area might be less tolerant of re-sealing if the alignment of the two surfaces is not identical every time.
The hose end in your picture looks to be mechanical assembled on to the tube and braid, rather than the swaged type. Personally I am not in favour of SS braided brake lines on a road car because I have been told they suffer from corrosion. Not a problem on a race car with continuous inspection or if the car is only used a few times a year on dry roads.
Ian
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