Stainless Steel Braided Brake Hoses

In common with the majority of brake systems, the Elise brake system comprises metal piping and rubber hoses. As the brake pedal is depressed, the brake fluid in the system is forced into the brake cylinders, pushing the against the pistons which in turn press the brake pads against the brake disc. When under severe pressure the rubber hoses can expand a little, resulting in a softer pedal 'feel'. Replacing the rubber hoses with stainless steel braided ones prevents expansion thus maintaining a firm pedal 'feel'.

The fluid plays an important role and many people are unaware that it should replaced after two years, irrespective of how many miles the car has travelled, as the fluid absorbs moisture over time. Here's an interesting fact; when a car's brake fluid is one year old, it contains 2.5% water. At 18 months the water content is up to around 3% which is enough to lower the boiling point of the fluid by 25%. After a few years, the fluid can have 7% to 8% water. I'd like to acknowledge that this is a summary from a very interesting article at Lotus Elan Central and suggest you take a look at Doug's site for more information.

Now you know more about the fluid I should point out that you might transform your brakes and brake 'feel' by simply replacing the fluid, particularly if you have no idea when it was last done!

This step-by-step guide will show you how to replace your rubber brake hoses for stainless steel braided versions. I'll point out a couple of things that aren't covered in any other guides I've seen and, of course, the whole guide is made as simple as possible through the extensive use of photographs in the Elisenet tradition!

WARNING. YOUR BRAKES ARE ESSENTIAL TO YOUR SAFETY AND THE SAFETY OF OTHERS. PLEASE MAKE SURE YOU HAVE READ, UNDERSTOOD AND AGREE TO THE IMPORTANT DISCLAIMER ON THE ELISENET HOME PAGE SHOULD YOU DECIDE TO FOLLOW ANY OF THE INFORMATION THAT FOLLOWS.

What you need:

1. Goodridge Brakeline Kit, Part Number TLS1100-4C.

Available from Eliseparts.com, £65.95 exc. VAT & P&P;

2. 6mm (1/4 inch) Stainless Steel Rubber Lined P-Clips (x 4).

Available from Aerotek, Part Number 171-3C, £0.95 each exc. VAT & P&P;

3. 5mm Stainless Steel Nyloc Nuts (x 4).

Available from Aerotek, Part Number M5NYC, £0.11 exc. VAT & P&P;

4. Duralac MSDS anti-corrosive jointing compound, Lotus Part Number A111C6017S.

Available from LightAero.co.uk, Part Number DTD369B, £4.16 exc. VAT & P&P.

Alternatively, pay more for the same product from Lotus using the Lotus Part Number at Race Speed, £16.48 exc. VAT & P&P;

5. Castrol SRF Racing Brake Fluid (the best DOT 4 non-mineral fluid).

Available from Race Speed, £39.00 exc. VAT & P&P;

6. Brake Piston Removal Tool, Lotus Part Number T000T1242.

Available from Race Speed, £22.00 exc. VAT & P&P.

Alternatively, use the 'Rear brake adjusting tool' available from Eliseparts.com, £9.95 exc. VAT & P&P.

Alternatively, use a pair of long-nose pliers;

7. Permabond Anaerobic Adhesive, Lotus Part Number A912E7034 (for front caliper retaining bolts).

Available from Lawson HIS Ltd, (50ml) £7.79 exc. VAT & P&P.

Alternatively, pay more for the same product from Lotus using the Lotus Part Number at Race Speed, £25.58 exc. VAT & P&P.

8. Gunson EeziBleed system;
9. Tyre inflator (the EeziBleed uses compressed air from your tyres);
10. 10mm Spanner (for P-Clip retaining nuts);
11. 11mm Spanner (for bleed valves);
12. 13mm, 15mm and 17mm Spanners (for brake hose ends);
13. 8mm Hex Socket (for front caliper retaining bolts);
14. Torque Wrench (for front caliper retaining bolts);
15. 3mm punch (or 3mm hexagon (Allen) Key) (for pad retaining pin);
16. Hammer (for pad retaining pin);
17. Wire brush (to clean the P-Clip wishbone screws);
18. Adjustable Screw Clamp (x 2) (for retaining rear caliper piston).

Alternatively, use two 55mm lengths of 20mm x 20mm wood;

19. Container, tubing and peg (for old brake fluid);
20. T15 Torx (for radiator water shield fixings);
21. Jack & Axle Stands (x 4);
22. Wheel spanner;
23. Disposable latex gloves (e.g. Halfords) (brake dust is horrible);
24. Plenty of clean rags (honestly, brake dust is really horrible);
25. About two hours time.

A few words about using Stainless Steel P-Clips and Nyloc Nuts. Put simply, corrosion can occur when two different metals are joined to each other. There's a straight-forward explaination by Brian Martley to be found on the Elise-faq entitled "Stainless Fasteners - Good or Bad". Whilst mixing materials means that preventative steps are required to prevent corrosion, the original fitment of carbon steel (mild steel) parts brings with it other corrosion (rust) problems, as you'll see on your car. There are a variety of approaches to deal with this (use similar materials, provide a grease barrier and so on), I've chosen to use Duralac (which is used by Lotus when, for example, assembling the alloy hub carrier with steel shim plates to the steering arm). You choose!

Supplementary (22 November 2003).

My thanks go to Bruce and Morgan for their additional tips (posted on the Lotus BBS) that I have incorporated into this Guide.

Bruce suggests an alternative method for bleeding the brake system, and for fitting the rear hoses. I hadn't followed Bruce's method, but it's included here for your information:

Firstly I don't see the need to bleed the whole system dry. I do one hose at a time, bleeding each one as I go - it's a little easier and also you know where any air is if the pedal's not firm, because you make sure it's firm after doing each one.

Also, there's no need to get any air in the front calipers in the first place. I remove the caliper, then using a bit of wood or a pair of pads in the middle, press the brake to get the pistons right out (not falling out!). Then, you basically have calipers with loads of fluid in.

Then I disconnect the inboard end of the hose, keeping fluid spillage to a minimum with fingers and rags...attach the inboard end and let fluid drain out to the tip of the new hose...you now have very little air anywhere.

I then screw the hose to the caliper. Once tight, I retract the pistons, pushing any air that might be there back up to the master cylinder and out, thus filling the new lines with fluid and no air...then bleed through with new fluid.

Also - at the rear there's no need to remove the discs - it's much easier to undo the top bolt (17mm socket) and swivel the caliper back out of the way - then you don't need to disturb the discs at all. The bolt should be done back up to 50NM with Permabond A131 on it.

So that's just all IMHO obviously - it's just the easiest way I've found of doing the job - but probably not as clean and you need to be quick with rags / fingers.

Morgan has provided additional material to ensure all air is expelled during the clutch bleeding process, this has been incorporated into the main text (Step 31).

Step 1: Remove the Wheels

Remove the security wheel nuts and lightly loosen the remaining wheel nuts by following Steps 2 and 3 in the Engine Cover Cable fitting guide. Now remove all four road wheels by following Step 2 in the Race Exhaust fitting guide.

Step 2: Preparation

Open the front compartment lid (i.e. the bonnet) and keep it open by supporting it with a length of wood. Remove the emergency tyre (the can of Tyre Weld!). Remove the brake fluid reservoir filler cap and clean it, taking care to ensure no fluid comes in contact with any paintwork. Now remove the simple filter (pictured right) by withdrawing it slowly so that the fluid drains into the reservoir. Use a rag to clean the filter.

To ease the access to the front upper brake hose fittings, remove the five (T15 Torx) plastic fixings securing the radiator water shield to the top rear edge or the radiator monting panel, and withdraw the shield. Put it and the five fixings safely to one side.

Step 3: Remove the Bleed Nipple Caps

Step 4: Drain the Front Nearside Caliper

Step 5: Disconnect the Front Top Hose Connection

The flexible brake hose is connected to the fixed metal hose pipe visible through a slot cut into each panel protruding from each side of the windscreen frame. From what I can tell from postings on the Lotus BBS, it would appear that earlier cars do not have this slot and that the recommended course of action is to drill and file each panel to provide the necessary access.

You'll now need your 13mm, 15mm and 17mm spanners. Referring to the diagram below, undo the 13mm sleeve whilst holding the 15mm hose fitting in position. This will free the metal brake pipe from the top of the hose. Now undo the 17mm lock nut whilst holding the 15mm hose fitting in position. This will free the hose from its mounting. Retain the lock washer as you'll need this when fitting the stainless steel braided hose.

Step 6: Remove the Hose P-Clip

Step 7: Free the Hose from the Caliper

The flexible brake hose can now be unscrewed from the caliper using a 15mm spanner.

Step 8: Remove the Front Caliper Retaining Bolts

Step 9: Connect the Stainless Steel Hose to the Caliper

No pictures here as this is very simple. Take one of the new stainless steel braided brake hoses and discard the lock nut provided at one end. Screw this end of the hose into the caliper. Tighten (but not too much else you'll damage the caliper!) using a 15mm spanner. Position the caliper back onto the hub carrier but don't secure in place just yet.

Step 10: Connect the Stainless Steel Top Hose Connection

We'll now connect the new stainless steel braided brake hoses to the fixed metal pipe. Following the graphic in Step 5 above, feed the threaded end of the hose through the body panel and secure using the lock washer and new lock nut. Tighten in place. Now position the flared end of the metal pipe against the end of the hose and secure using the sleeve, preventing the hose from turning using a 15mm spanner on the hose fitting. Take care not to overtighten the sleeve!

Step 11: Repeat on the Offside

Follow Steps 4 to 10 on the offside, leaving the caliper in place against the hub carrier but not secured (as before).

Step 12: Drain the Rear Nearside Caliper

As with the front calipers, take the length of clear tubing and push it onto the rear nearside caliper bleed nipple. Put the other end into the container and peg in place as before.

Open the bleed valve (11mm spanner) a few turns then gently pump the brake pedal so that any remaining fluid in the pipework is drained into the container. There wont be much left.

Step 13: Rear Brake Pad Removal

Step 14: Remove the Brake Discs and Pads

Remove the outer pad. To remove the inner pad and gain access to the caliper piston it is necessary to remove the brake disc. This is where my car differs from the description in the Elise Service Notes. The Service Notes describe the need to remove a single socket head screw that retains the brake disc against the hub. If you have this, remove it now. If your car is like mine, there wont be a screw to remove (it's not missing, there's no hole in the disc!).

Mark the orientation of the disc on the hub, so that it can be replaced in the original position. The disc simply pulls away from the hub. A gentle hammer tap on a piece of wood positioned next to each wheel screw will ease the release of the disc. Once the disc is free the inner pad can be removed. Note that you should mark the metal side of the pads so that you can put them back into their original position.

Step 15: Screw Piston into the Caliper

Screw the piston into the caliper, gently pressing on the tool to help ease the piston in. Do this with the bleed valve open so that fluid in the caliper drains out. The piston is fully retracted when its face is level with the compressed piston boot. At this point the piston will continue to rotate without retracting any further.

Pictured below you can see the piston being screwed back into the caliper using the Lotus tool.

Step 16: Clamp the Piston in the Caliper

Use a clamp to retain the piston in the caliper. No need to tighten it, this Step will prevent the piston from being pushed back out when we bleed the system.

Step 17: Disconnect the Rear Top Hose Connection

The rear hose is fixed in the same manner as the front hose so, following Step 5, unscrew the 13mm sleeve and then the 17mm lock nut, enabling the top part of the flexible hose to go free.

Step 18: Remove the Hose P-Clip

Step 19: Free the Hose from the Caliper

The flexible brake hose can now be unscrewed from the caliper using a 15mm spanner.

Step 20: Connect the Stainless Steel Hose to the Caliper

Take another new stainless steel braided brake hose and discard the lock nut provided at one end. Screw this end of the hose into the caliper. Tighten (but not too much else you'll damage the caliper!) using a 15mm spanner.

Step 21: Connect the Stainless Steel Top Hose Connection

You're now experienced at this! Following the graphic in Step 5 above, feed the threaded end of the hose through the body panel and secure using the lock washer and new lock nut. Tighten in place. Now position the flared end of the metal pipe against the end of the hose and secure using the sleeve, preventing the hose from turning using a 15mm spanner on the hose fitting. Take care not to overtighten the sleeve!

Step 22: Fit the Stainless Steel Hose P-Clip

Use a wire brush to clean the threaded screw welded to the rear wishbone. Adjust the position of a new stainless steel P-Clip on the new braided brake hose so that the path of the hose has no tight bends or obstructions. Spread a thin layer of Duralac MSDS anti-corrosive jointing compound on the thread and the part of the P-Clip that will come into contact with the wishbone. Using a 10mm spanner, screw the stainless steel nyloc nut onto the threaded screw to secure the hose P-Clip to the wishbone.

Step 23: Repeat on the Offside

Follow Steps 12 to 22 on the offside.

Step 24: Clean the Fluid Reservoir

Step 25: Bleed the System: General EeziBleed Guide

Rather than repeating the EeziBleed instructions, I'll point out a few hints from my own experience:

1. Use the plastic reservoir cap;
2. Fit the thick rubber seal into the cap (the reservoir is manufactured by ATE and has a 45mm diameter thread);

3. Check that all the bleed valves are closed;
4. Release air out of one of the tyres until it's down to 20 psi;
5. Connect the EeziBleed pressure vessel to the reservoir, then attach the tyre connector to the wheel. Check and fix any air leaks (at the device, reservoir cap, and all the new hose connections);
6. Remove the tyre connector;
7. Fill the pressure vessel with brake fluid. Stand the vessel vertically near the reservoir and reconnect the tyre connector;

8. Bleed each wheel caliper at a time, in the order of decreasing brake line length. For the right-hand drive Elise this means:

1) Rear Nearside;

2) Rear Offside;

3) Front Nearside;

4) Front Offside.

9. Connect the bleed tube to the bleed nipple, open the bleed valve (allowing the fluid to flow freely) until the fluid caught in the container is clean and air free (absolutely no bubbles). Retighten the valve;
10. Repeat for each wheel, noting the specific points relating to the front calipers below;
11. Check that the fluid in the pressure vessel does not drop below the minimum level line (refill as required);
12. Remember to disconnect the tyre before removing the cap from the reservoir or refilling the pressure vessel;
13. Between calipers, check that there is air in the tyre and pump back up to 20 psi if there is little pressure remaining.

Step 26: Bleed the System: Front Calipers

In order to remove all air from the front calipers it is necessary to invert them during the bleeding process. This is because the caliper has two pistons (one on each side), fluid being fed to the outer piston via a tube at the bottom of the caliper.

Inverting the caliper allows air to rise to the pipe which is then forced into the outer piston compartment and out through the bleed valve. When bleeding it is best to imagine where any air may have risen to and gradually invert the caliper through 360 degrees. Once all the air bubbles have gone you can close the bleed valve.

Don't pack away the EeziBleed system yet, we'll need it later on.

Step 27: Complete Front Nearside Hose and Caliper Reassembly

Use a wire brush to clean the threaded screw welded to the front wishbone. Adjust the position of a new stainless steel P-Clip on the new braided brake hose so that the path of the hose has no tight bends or obstructions. Spread a thin layer of Duralac MSDS anti-corrosive jointing compound on the thread and the part of the P-Clip that will come into contact with the wishbone. Using a 10mm spanner, screw the stainless steel nyloc nut onto the threaded screw to secure the hose P-Clip to the wishbone.

Refit the two 8mm hex socket bolts securing the brake caliper to the hub carrier. Apply Permabond A131 to the threads of the bolts, fit the caliper over the disc and secure to the hub carrier using the two bolts. Use a torque wrench to tighten to 45 Nm (33 lbf ft). Note: over tightening could ruin the thread in the caliper, or even crack the caliper housing. It is really advisable to use a torque wrench!

Step 28: Complete Front Offside Hose and Caliper Reassembly

Repeat Step 27 for the front nearside hose and caliper.

Step 29: Reassemble Rear Nearside Brake

Before re-fitting the brake disc, clean the mating faces (disc and hub) so that you'd be happy to eat your dinner off them. This will stop any vibration from misalignment due to dirt being trapped between the surfaces. I used wire wool, but fine emery paper will do the job too (whatever you use, make sure all debris is blown away).

Remove the clamp securing the piston in position. Slide the inner brake pad into its slot in the caliper, then refit the brake disc into its original position using the marks applied in Step 14 (if originally fitted, secure with the countersunk retaining screw to 12 Nm). Slide the outer brake pad into the caliper. Now refit the pad anti-rattle spring in the caliper, making sure the spring ends are located in the recesses provided. Referring back at the pictures in Step 13, insert the Pad Retaining Pin so that it passes through both eyes of the Anti-Rattle Spring and both brake pads.

Push the Pin fully home, use a punch (or Allen key) to ensure the snap ring is seated flush with the outside edge of the caliper.

Step 30: Complete Rear Offside Hose and Caliper Reassembly

Repeat Step 29 for the rear nearside brake.

Step 31: Bleed the Clutch

Here's a job most (all?) other guides forget. The clutch and brake systems have a common fluid reservoir. This means that there is the possibility of contaminating the new brake fluid with old clutch fluid (that is in the clutch pipework) over time.

Open the engine cover and find the clutch slave cylinder which is located on the transmission close to the nearside cockpit bulkhead. Take the cover off the bleed nipple and connect your drain tube and container as you did for the brakes. Set the EeziBleed system up so that the reservoir is under pressure (remember to check that there is new fluid in the pressure vessel!). Open the bleed valve and drain the old fluid out whilst pressing in the clutch operating lever so that the pushrod is fully closed (to dispell any air in the cylinder), then close the valve, tightening to 7 Nm. Replace the bleed nipple cover. Job done!

Step 32: Finish!

Now to put everything back in place:

1. Refit the four brake caliper bleed nipple caps;
2. Refit the radiator water shield using the five (T15 Torx) plastic fixings;
3. Press down on the brake pedal a few times and pull the handbrake on and off in order to reseat the brake pads. This will result in fluid transferring into the space created by the pistons in the calipers, so (not yet) you'll need to top-up the reservoir;
4. Place the brake fluid filter in the reservoir, being careful not to force fluid to overflow (i.e. place it in slowly and gently);
5. Now top-up the brake fluid reservoir to the 'Max' level;
6. Refit the brake fluid reservoir filler cap;
7. Refit the can of Tyre Weld;
8. Check the tyre pressures and refit the wheels. Tighten the wheel nuts to 80-85 Nm. Refit the security wheel nut covers and replace the key into its position in the front of the car.

Do a final recheck that no parts are left over, that all tools are out of the way and no leaks are visible. The brake pedel should have a firm 'feel'. Go for a test drive, then recheck for any leaks. All OK? Smile and congratulate yourself for doing a great job!