8 replies to this topic

[Nookie]

Just going great guns with the re build then tried to connect the front to rear brake line to the three way union on the rear subframe and Doh stripped the thread, is replacing the whole line easy enough to do as there is no room to do a new flare and union repair? are the unions front and back the same (93 Mayfair) and would you remove the rear subby to route the pipe up and over? any tips Cheers Nookie

[bmcecosse]

I suspect the unions will NOT be the same - front will be M10x1  and the rear 3/8" UNF.   Put in a new pipe in KUNIFER.  You should be able to thread it down behind the front subby - leave it long at both ends and put in a coil or two to allow for future repairs etc.  

[A-Cell]

Unless you need to replace the whole pipe eg for corrosion , then just cut and join a piece using a connectors. also No need to remove the rear subframe, unless you ar after originality. Route the pipe under thebsubframe.

Edited by A-Cell, 02 August 2013 - 08:08 PM.

[Noris8322]

I've just changed this brake pipe, as the original got damaged by the paint shop. It almost impossible to follow the route of the original pipe if the rear subframe is still in place. So instead I run the pipe under the subframe and secured it with a P-clip. You can buy the correct pipe, pre-made from Minispares ctr  

[Nookie]

Brilliant thanks for your replies.

[Captain Mainwaring]

If you use the dreaded and much maligned copper piping, you can form a swan neck and feed it over the subframe where the tunnel lump is - just clip it under is fine though....

[tiger99]

No it is not. The pipe is routed above the subframe specifically to protect it from being caught by debris and ripped off. It is not all that hard to do the job properly, but there must be a large loop left to allow some flexing as the subframe moves slightly on its mounts. Even so, a copper pipe will rapidly fracture in that position. Cunifer is ok, but make the loop slightly larger than original, or increase it to 1.5 turns instead of a plain U bend.

[Captain Mainwaring]

No it is not. The pipe is routed above the subframe specifically to protect it from being caught by debris and ripped off. It is not all that hard to do the job properly, but there must be a large loop left to allow some flexing as the subframe moves slightly on its mounts. Even so, a copper pipe will rapidly fracture in that position. Cunifer is ok, but make the loop slightly larger than original, or increase it to 1.5 turns instead of a plain U bend.

 

If you've ripped that off, then you've taken the subframe off with it, together with half the floor pan,and, for what it's worth, i'll eat your underpants without sugar if a copper brake line fractures because of flexing between subframe and body. The subframe was above the floor pan last time I looked - surely the brake pipe on the floor pan would get damaged first? 

 

I'm all for good engineering, but I think this scaremongering is just a bit heavy, don't you?

Edited by Captain Mainwaring, 04 August 2013 - 12:03 PM.

[A-Cell]

The brake pipe was routed above the subframe due the precedence of the manufacturing processes. Brake pipe to body first, then further along the line install the subframe. There is clearance against the heel board and under the subframe to route the brake pipe around the subframe. A standard method of replacing the corroded portion of pipe behind the subframe for MOT purposes for the last 50 odd years.