How do the Brake Lines run?

[WilST]

I have a PO-induced conundrum hopefully you folks can help me with. The PO's resident "expert" (the PO was a rich guy) decided to re-do the brake lines in steel of my LHD S2 and made a hash of it. Attached are a few pictures of how my front lines were run, what a mess. It's hard to mess up the rear ones, being so simple, but I'm going to re-do them anyhow because I want them all to be in cunifer.

I would be grateful if fellow listers could submit some pictures of how the brake lines are run on their LHD S2, I have nothing to go by on my car, and what books I have don't show the routing of the brake lines.

Thanks,
Wil

[billwill]

Those might be the original placements. I recently replaced my steel (Bundy) pipes with Kunnifer ones as the steel had rusted at one of the fittings.

In the RH drive car the front pipes meet as shown at a 5 way junction fastened to the chassis near the oil filter. It looks as if your LH drive car left it like that and then brought the feed from the brake master all the way over from the left side to the 5-way junction.

This diagram shows the RH drive brake pipe placements. http://www.lotuselan.net/wiki/JA_-_Brakes_-_Bundy_Pipes

[prezoom]

Early on in my S2 ownership, I experienced an unusual braking issue. The PO had routed the front cross brake line across the rear of the vacuum tank, placing it very close, almost touching, the oil pan. On a very hot summer day, and stuck in stop and go traffic for what seemed like a lifetime, enough heat was transferred from the pan to the brake line to heat/boil(?) the fluid, causing a minor lockup of the opposite wheel. More like a significant pull to that side. I rerouted the line to the top of the vacuum tank and have not had a problem since.

[nmauduit]

Early on in my S2 ownership, I experienced an unusual braking issue. The PO had routed the front cross brake line across the rear of the vacuum tank, placing it very close, almost touching, the oil pan. On a very hot summer day, and stuck in stop and go traffic for what seemed like a lifetime, enough heat was transferred from the pan to the brake line to heat/boil(?) the fluid, causing a minor lockup of the opposite wheel. More like a significant pull to that side. I rerouted the line to the top of the vacuum tank and have not had a problem since.

This sounds surprising as brake fluid can hardly boil from engine oil temperature : typ. boiling temp 230?C (DOT4) or greater (unless massive amounts of water is present in the brake line) vs. overheating engine temp 120?C or 130?C max I would think (that would be high revs under load, not traffic jam); plus when brake fluid boils the cold fluid gets back to the MC tank and resulting effect is zero pressure on the brakes (even with pedal pressure) rather than lock-up...

An other story is when a brake pad actually catches permanently (piston stuck or otherwise) and can get the disk very hot : then the pad can transfer some heat to the piston and get the brake fluid to boil, from the disk heat out of friction (then again pedal to the floor).

[prezoom]

What made me think it was excessive heat was, I eventually pulled off into a convince store, and bought a large bottle of water to try pouring on the line. After the stop and the water, the brakes returned to normal. Traffic had also thinned at that point. After moving the line, I drained the unknown brake fluid and installed Motul, which I have found to be the best brake fluid I ever found when I was racing.

[WilST]

I guess it makes sense that, for a LHD drive car, the simplest way for the factory to deal with it is to make a run from the master cylinder all the way round to the four-way fitting next to the oil filter as used on RHD cars--but then one has to double-back to the LF caliper. I would've thought they'd start from the master cylinder, T-off to the LF caliper before the vacuum tank, then on to (what would be) the three-way fitting. Saves on tubing and labour. That's what I'm wondering if they did or not. Maybe there's a hydraulic issue with T-ing off willy-nilly, but then again that's basically what happens where the either 3-way or 4-way fitting Ts off to the rear brakes T-fitting.

Ah well, just need to find some pictures of how the factory did it on LHD cars.

[nmauduit]

I guess it makes sense that, for a LHD drive car, the simplest way for the factory to deal with it is to make a run from the master cylinder all the way round to the four-way fitting next to the oil filter as used on RHD cars--but then one has to double-back to the LF caliper. I would've thought they'd start from the master cylinder, T-off to the LF caliper before the vacuum tank, then on to (what would be) the three-way fitting. Saves on tubing and labour. That's what I'm wondering if they did or not. Maybe there's a hydraulic issue with T-ing off willy-nilly, but then again that's basically what happens where the either 3-way or 4-way fitting Ts off to the rear brakes T-fitting.

Ah well, just need to find some pictures of how the factory did it on LHD cars.

My Federal S4se has actually 3 lines running on the vacuum cross member, since it has the tandem master cylinder... but that would not apply to your S2

[WilST]

My Federal S4se has actually 3 lines running on the vacuum cross member, since it has the tandem master cylinder... but that would not apply to your S2

How are the lines attached to the vacuum cross member on your S4? Obviously they don't drill mounting holes in it. The PO on my car rigged up these awkward braces that hold the two lines going across the vacuum member.

[nmauduit]

How are the lines attached to the vacuum cross member on your S4? Obviously they don't drill mounting holes in it. The PO on my car rigged up these awkward braces that hold the two lines going across the vacuum member.

I don't have these tubular protections, my lines are mainly held by some steel tabs welded on the cross member (from memory 1/4" wide and 1" or 1"1/2 long) and bent around the lines (plus the multiple way fitting that is bolted to the frame, and occasional P-clip each side of the cross member) - they also are quite rigid so don't move much (the cunifer version would need more support - though I personally would not use cunifer because of the higher risk of a puncture when striking it with a tool or an engine).

[pharriso]

My Federal S4se has actually 3 lines running on the vacuum cross member, since it has the tandem master cylinder... but that would not apply to your S2

Same on my LHD Federal Sprint, the design is ahem... pretty stupid....

The line for the front brakes goes from the master cylinder over the vacuum tank to a 3 way splitter on the RHS of the chassis. The line for the LH front caliper then returns over the tank...

Why they could not put the splitters on the LHS of the chassis on LHD cars is beyond me...

[billwill]

Possibly they would get too hot from the exhaust manifold on the LH side.

But it's more likely that more of the parts (pipes) are standardised by keeping the branch points on the RH side.

[S2Jay]

Hi Will,

I have a LHD S2, and it looks like your setup is similar to mine, except for the PO added bracing.
I believe that this car is mostly original, and likely the brake piping is all original. This is S2 26/5009, so a bit later than yours, but looks very similar at least regarding the brake line routing.

I have a number of pics taken near the beginning & during the ongoing rebuild of this car after the engine/trans was out. I will post a few pics here, but if you need any further detail, I have loaded a few more into Flickr.

Not sure if these are just what you need, but if I can be of any further assistance, let me know.

https://www.flickr.com/gp/68999653@N07/eq6spG

[WilST]

S2Jay, thanks very muchly, that set of pictures is about perfectly what I'm looking for!
Sorry for the delay in getting back to you, finally made it home.
Regards,
Wil

Hi Will,
I have a number of pics taken near the beginning & during the ongoing rebuild of this car after the engine/trans was out. I will post a few pics here, but if you need any further detail, I have loaded a few more into Flickr.
Not sure if these are just what you need, but if I can be of any further assistance, let me know.
https://www.flickr.com/gp/68999653@N07/eq6spG

[WilST]

...and you have some really great photo albums on Flickr too!

Thanks Again,
Wil

[S2Jay]

Wil,

Thank you for the kind words, always glad to help when I can. Also glad that you enjoyed the pics in other albums.

I am still loading albums & pics into the "Flickr" site since I have just recently found that they provide 1 TB of storage free.
Jay
_______________________________________________________________________