Vixen S2 rear brake cylinders upside down?

[NicBowman]

Hi, still rebuilding, three steps forward two steps back.

I appreciate all the input I have got from the group and from the TVR club forum.

Another…. Rear brake cylinders, the originals had the hose at the bottom, as expected and bleed at the top. But, that is not how they are supplied or designed.. The female form for the bleed is the lower one, the upper is a male cone (within the female thread form) as opposed to female in the lower. So, sealing not as designed and a bit dodgy, honestly.

What is the story? Just reverse the bleed as it was? Or keep the hose at the top and struggle to bleed?

Thanks


Nic

[Adrian@]

That I know of it has never been an issue, mine are as was (it is used this way up on other cars). An issue with the copper washer sealing if you are using braided hoses with smaller than OE/OD fitting, as the copper washer needs to be made bespoke (create your own with a OD correct copper washer filed out to spin down the 3/8 thread of the hose) to stop it from exuding out from the slave face/hose fitting and then leaking. A@

[Moto]

NicBowman said:

Hi, still rebuilding, three steps forward two steps back.

I appreciate all the input I have got from the group and from the TVR club forum.

Another…. Rear brake cylinders, the originals had the hose at the bottom, as expected and bleed at the top. But, that is not how they are supplied or designed.. The female form for the bleed is the lower one, the upper is a male cone (within the female thread form) as opposed to female in the lower. So, sealing not as designed and a bit dodgy, honestly.

What is the story? Just reverse the bleed as it was? Or keep the hose at the top and struggle to bleed?

Thanks


Nic

Hi Nic,

My rear brake cylinders were hose at top and bleed at the bottom. This was how the car was when I bought it and as now after the rebuild. I presume that is correct but ....

I don't understand why you suggest sealing is not as good. Certainly I've never experienced any sealing issue.

Before :



After :



Hope these photos help.

Moto

[LLantrisant]

a brake cylinder sould always have the bleeding-screw on the highest point...at least higher than the lqiuid-entry-point.

otherwise you risk not being able to bleed 100%

[Adrian@]

All the Thurner designed chassis TVR's are run like this and I have never known an issue. A@

[NicBowman]

Hi

Thanks!

Moto, in answer, the form of the machining inside the two female ports differs. The bleed screw (lower holes as fitted to TVR) is a female cone, designed to mate with the male cone on the bleed nipple. The upper port is a male cone within the female. Hence using the bleed nipple in the upper puts a male cone (on the bleed nipple) against a male cone in the housing. Hence, sealing of the bleed nipple if fitted in the upper port is male cone to male cone. Obviously not ideal. But, clearly people do it and it seems not to cause problems. You have it 'right' way from a design point of view ref sealing.

I will leave it as Moto's, but, if it won’t bleed properly I can reverse easily enough.

Nic

Edited by NicBowman on Thursday 5th January 07:57

[NicBowman]

Hi

Thanks!

Moto, in answer, the form of the machining inside the two female ports differs. The bleed screw (lower holes as fitted to TVR) is a female cone, designed to mate with the male cone on the bleed nipple. The upper port is a male cone within the female. Hence using the bleed nipple in the upper puts a male cone (on the bleed nipple) against a male cone in the housing. Hence, sealing of the bleed nipple if fitted in the upper port is male cone to male cone. Obviously not ideal. But, clearly people do it and it seems not to cause problems. You have it 'right' way from a design point of view ref sealing.

I will leave it as Moto's, but, if it won’t bleed properly I can reverse easily enough.

Nic

Edited by NicBowman on Thursday 5th January 16:37

[nwarner]

As Adrian said they are the same way up on other cars and I have them on my Scimitar SE5A and Austin 1800 and never had any problems when bleeding them and also no problems when bleeding the brakes on my Vixen.

Nige