Rubber Brake Line Collapse - What Causes This?

 Light, simple, safe. We obsess over those three words. But even the humble parts—like rubber brake hoses—age out. A recent case on a very low-mile ’05 Elise reminded me how quietly time can catch up and change how a car stops.  Disaster struck this car when the rear driver side caliper locked up.  Fortunately the owner was able to nurse the car home safely and have it towed to us for repair.  

Symptoms were odd: only one rear corner dragged; eventually it freed itself. Fluid was old but in OK condition. The car still had its original OEM rubber brake lines. My working theory: internal hose aging created a one-way restriction—easy pressure in, slow/no return—so the caliper stayed applied longer than it should resulting in a smokey brake and a fully locked up corner!

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How OEM Rubber Brake Hoses Are Built

An Elise OEM hose looks simple, but it’s a multi-layer composite that works hard every time you hit the middle pedal.

• Inner liner (EPDM): Carries brake fluid; resists heat/chemicals.
• Reinforcement braid: Limits expansion under pressure.
• Outer jacket: Protects from heat, ozone, abrasion.

Nothing exotic here—and that’s the point. It’s good, durable, serviceable… but it still ages and why we wrote a previous: BLOG

What Age Does to Brake Hoses

Outer cracking is easy to spot. The sneaky failure is inside the hose—where you can’t see it.

Failure mode	How it develops	Real-world symptoms
Internal collapse / check-valve effect	Inner liner hardens, micro-cracks, or delaminates; a flap or swelling narrows the bore.	One corner drags, brakes feel uneven, wheel runs hot; caliper may “release itself” later.
Reinforcement fatigue	Braid loses stiffness after years of heat cycles and moisture.	Softer pedal, more travel, vague response under repeated stops.
Outer jacket degradation	UV, ozone, road spray, or heat near rotors/exhaust.	Visible cracking, surface bubbling, damaged sections near fittings.
Fluid & moisture interaction	Old DOT 4 absorbs water; moisture + time accelerates internal deterioration.	Lower boiling point, discoloration, more fade when hot.

Yes, even Exiges...

Why only one side? Hoses age unevenly: routing, heat (exhaust proximity), flex cycles, and tiny manufacturing variances mean one line can fail years before its twin.  See the picture below of the Elise that failed and note the sourcs of heat.

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OEM vs Upgrade Options

• Fresh OEM rubber: Restores factory feel; perfectly fine for road cars.

• InoKinetic braided / stainless kit: Improved pedal consistency, durability, and peace of mind. Designed specifically for Elise/Exige fitment.  Our QWKbleed SS Lines are worth a look - see them: HERE

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Elise Brake Hose Refresh: Quick Checklist

• Replace all four hoses together. Don’t chase symptoms one corner at a time.
• Flush with fresh DOT 4. Bleed thoroughly; check for equal flow at each corner.  We like: Motul
• Inspect calipers. Verify pistons, seals, and slide pins; address any asymmetry you find.
• Route & secure. Ensure full droop/compression clearance, no twist, no chafe.
• Road-test & heat-cycle. A/B stops, then re-check for drag or wheel-to-wheel temperature differences
• Set an interval. For street cars: consider 10–15 years as a practical horizon; sooner for heavy track use.

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Bottom Line

Yes, even new Emiras will eventually succumb...

Rubber brake lines don’t ask for attention—until they do. If your Elise or Exige is still on originals, consider this your nudge. Replace the hoses, flush the fluid, verify the calipers, and get back to what the car was built for: precise, confidence-inspiring braking that lets you carry speed where it counts. 

4pt Harness Install Considerations for the Lotus Emira

 Safely fitting the Schroth Profi II 4pt harnesses into an Emira is a priority for us.  We know many weekend warriors have bought the Emira to drive on the road AND track.  We have long been fans of the Schroth harnesses and sell them exclusively.  Now that our QUADloc Harnessbar is in production, we could turn our attention towards a suitable 4pt harness.

The shoulder belts are easy to fit and will work perfectly with a harnessbar.  The waist belts are the challenge when it comes to fitment.  Fortunately the Emira seems quite friendly to the addition of waist belts while still maintaining the stock 3pt belts.  

The inboard belt attaches slightly different than the outboard belts.  Both are easy to access and offer enough thread engagement to make adding a waist belt a possibility.

Schroth offer different tabs to attach the belt so we have some options.  There are two options that we investigated.  One of the tabs was designed for the Elise/Exige and looks quite conventional - triangular in shape.  The other tab is a specialized tab that Schroth developed and we have used in many applications.  This one is longer but offers flexibility - which is an advantage in this application.  

  The image shown to the right is the Schroth tab that we like for the Emira.  It can be bent to conform which the other tab can not.  It also provides better clearance for the 3pt bolt and tab that is shown in the image below.

good clearance

We will spec this tab on all the Emira belts that we will offer as a result of the better fitment.  Installing harnesses into a car will make you more confident as you will be in better control of the car.  Naturally the assumption is that you have installed harnesses in a safe and proper manner.  We're happy with this solution as it fits the bill.

Not so good clearance

Emira harnessbar Dev: Part 4

 Our QUADloc harnessbar has approx 1.25" of height adjustability.  The two anti-rotation mechanisms offer enough adjustment to make this possible.

Based on Schroth's recommendations for belt orientation, we will be compliant for the vast majority of drivers.  Interestingly enough, torso length is the critical measurement as overall height is not relevant.  We have had clients with very short legs but very long torsos.  These folks can sit very high in a seat.  We also have seen the opposite - clients with long legs and short torso.

Fine tuning the fitment will quite easy for clients and does not require advanced mechanical skills.

We the angle for the belt with the bar in the lowest position.  The driver is a 6ft guy and the belt angle is at -10.5deg.  This is within the 0-20deg spec.  If the bar were to be raised, we could reduce the angle even further.  

Emira Harnessbar Development Part 3

Love this version!

 

We have successfully test fit the latest version of our QUADloc harnessbar for the Emira.   Overall I'm pleased with it but we are going to add an additional gusset to the outer tabs to make that portion super strong.

I did some math on our Anti-Rotation mechanisms:

1. Primary anti-rotation: 1 on each side (two total)
• Each of the bolts that secure this mechanism will take 29,000lbs of force
• Total strength = 58,000lbs of force
2. Secondary anti-rotation = 1 on each side (two total)
• Total strength = 6,000 lbs

With two 180lb people in the car, wearing harnesses, they would exert approx. 5,400lbs onto the QUADloc bar  in a 30g crash.  Our QUADloc will restrain up to 64,000lbs.  I’m confident it will not rotate!

We also confirmed our adjustability that eases installation works as expected.  This will be a very easy bar to install thanks to the split main bar.  It will also ship very easily.

We are now finalizing the costs to manufacture along with the final weights.  

Emira Harnessbar Development

 We have test fit the second proto bar in the car.  I had a brainstorm during my trip to Japan -  jet lag fueled!   We will have two anti-rotation mechanisms in our QUADloc bar.  I decided that the primary mechanism will change in form from a bracket to a bar.  This bar will feature a cam mechanism that will allow the bar to lock into the car more securely.  We prototyped this bar and test fit it into our bar.  It works really well and will play an integral role is saving the rear shelf space.  

Additionally, we confirmed that we have full seat travel with the bar.  This will be great for the tall folks out there!

We should have the third and final prototype into the car this coming week.  Once we confirm fitment, we will move forward into production....and reveal our innovations to the community.
 

Emira Collision Part 2

The Emira rear subframe came in and was swapped. 

Jorge got the power unit back in the car and started it within a few days.  It lacked a muffler so we started it outside!

We discovered some interesting things that make this car better than the previous Evora.  There is an access panel for the wiring harness that is far more durable so assembly/disassembly is easier.

The ECU is located in the engine bay, whereas the Evora has it located within the passenger compartment.

Lotus Elise and Exige Stage 2 & Stage 3 Developments

 We have sourced a new cold air intake (CAI) from ITG.  We had worked with these guys back in 2005 but the intakes flowed too much air!  We did not have the tuning ability to deal with the added airflow so our car would get too lean.  Now that we have proper tuning ability, they are back on our shelf as I love the better filtration that their filters offer.

We have also sourced new headers that offer a decat or sportcat option.  These are made here in the US so we can avoid those pesky tariff and exchange rate headaches that are a constant challenge with this business.  The quality is great so we are pleased with the prospects.  Plus they offer a EPA Certified Catalytic Converter which will allow many of you to stay emissions legal in your state.

We know many clients are looking for solutions beyond a Stage1.  Both the CAI and Exhaust solutions will complement our other options.  We know that many of you are looking for NA solutions but some of you with SC are also interested in upgrades.  We are running the 111RS with the CAI, Header and Decat now with the KATANA3.  Much like our previous KATANA265, this new solution essentially features the same types of hardware with our updated tuning ability.

Brent will be in late Aug and we will begin to tune our cars with these various hardware options.

Emira Harnessbar

Driving a Lotus on track is something that is a joy. But for some of us, a harness to hold us in the seat, becomes an important upgrade to really feel in control.  But safety drives our designs and we strive to produce products that not only work properly but also meet our clients needs.

We have begun designing a new harness bar for the Emira.  Our goal is to create one that:

1. Safe
2. Will be easy to fit
3. No modifications to the car
4. Preserve rear shelf space
5. Light

We have been designing proper harness bars since 2004 for Lotus cars. We were the first to offer a solution for the S2 Elise/Exige in the US.

We created one for the S1 Evora and have created them for other cars like the Alfa 4C.

We understand the safety requirements for this type of product as we work closely with Schroth USA owner, Joe Marko. Joe has guided us over the years to advise us of the latest safety practices. This helps when we are unable to crash test our products!  Joe's advice caused us to make improvements to our first two Elise bars.

We all understand that anything less than a full cage, 6pt harnesses and race seat is a compromise but if it is done well, a safe solution can be created. We know most weekend warriors need a solution that still allows them to enjoy their cars on the street.

Our bar will be quite innovative and easier to fit. Ours will be safe but also light and bolt-in with NO modifications needed. Our bar will offer more shelf space behind the seats than other options.

Here is a picture of the first prototype - this is far from the final design but gave us what we needed to further flesh out our concepts.

ABS Block Delete for S2 Elise and Exige

 Some of you know that we are working on a simple solution to delete the ABS on the Elise/Exige.  The stock ABS comes off a Minivan from the 90s and is not a great performer.  'Black Ice" mode is a common issue for aggressive drivers - especially in bumpy conditions.

We have been working with Girodisc on an idea that would delete the ABS system and replace it with a simple block that would route the fluid to the front and rear circuits via a bias adjuster.  This would allow the driver to adjust the bias to his liking. 

We received the ABS Delete Block (need a better name!) to install.  It is on our ArtCar2 and has seen some quick street testing around our shop.  The block originally came with the bias adjuster connected to it but we decided to install a remote bias adjuster so we could place it in the cabin within reach of a driver.  The servo remains in the system but you lose the speedo.  This car runs the AiM MX2E so we are using the GPS antennae for speed.

The install is slick and I'm looking forward to getting it to the track to test.