Rear Calliper/Handbrake fitting/adjustment.
This is just an amalgamation of the information needed to set up a set of Dorman Rear brake callipers (part numbers CA10113L & CA10113R) and Algirdas’ handbrake levers with either the already-fitted or new handbrake cables. I’m pretty sure it also would apply to the original callipers if there has been a removal for any reason.
I am not wishing to take credit for any of this information, as it is all freely available either in the workshop manual, or elsewhere on the LEC site, but having just fitted a ‘full set’, including stainless flexible brake hoses, new solid brake pipes, rear suspension wishbones, and rear wheel bearings I found myself looking at so many ‘reference works’ in order to get it all to work, that I thought a bit of a write-up was in order.
Jack Axle stand(s) Wheel-brace Spanners (wrenches) – 10mm, 11mm, 17mm, 18mm, 19mm. Pipe wrench, monkey wrench Sockets – 17mm, 18mm, 19mm Torque wrench Snipe-nosed pliers Selection of screwdrivers/lever bars or similar Small hammer
Lets start with the assumption that you have suitably supported the rear of the car (on flat ground) having taken off the handbrake, selected a gear and chocked the front wheels, removed the road wheels and are now looking at the bits inside the arch.
First thing to consider is the original pipework – examine the proportioning valves (aluminium ‘cylinder’ things about 4” long and 1” in diameter which are set between the solid brake pipe which comes from the front of the car, and the short solid pipe which connects to the flexible hose which runs to the wishbone.) if there is any sign of leakage, they should be replaced in matching pairs – they are not considered to be repairable. Next look at the condition of all solid pipes and flexible hoses. The original fitment pipes are steel and will possibly be showing signs of corrosion by now. The flexible hoses may be starting to perish and/or split. All pipe fittings in this area are ‘standard’ M10x1.0 metric brake fittings, and will probably be 11mm spanner size.
If you are replacing the flexible pipes, it will probably be necessary to replace all of the solid pipes from the proportioning valve back to the calliper – either because the old ones will be rusted solid, and/or will be too short to correctly fit the new Goodridge hoses.
Depending on what you are re-using, and what you are replacing, depends on where you go next – lets assume that all pipework on the car is okay (either existing or newly replaced) and we are only talking about the calliper itself.
Remember that any calliper/pipework which is not already in the car will have air in it instead of fluid, and brake bleeding by the ‘industry standard’ pedal-pumping method is not considered efficient on the Elan, it really is worth using a Gunsons Eezibleed with a maximum of 20psi in the tyre powering it.
Okay then, a bit of ‘theory’ here – the handbrake works on a screwthread which is operated by the lever on the back of the calliper – as the lever is pulled, the thread turns and pushes the calliper piston out and causes the calliper to clamp the disc and hold the car. When the handbrake is released, an external spring pulls the lever back to its starting position, releasing the piston from the disc.
Inside the calliper is a clutch mechanism which is the self-adjustment facility for the handbrake, but it will need to be set up to start with (or at least, I spent a long time sorting mine out, and wish I had known then what I know now about how it all works!)
I will concentrate on the Dorman callipers and Algirdas’ levers, as that is what I fitted – The levers come with clear instructions on how to fit them to the callipers – but they are basically a straight swap for the original items. One thing I should mention, it may be easier NOT to re-fit the return spring at an early stage, but just note which way it goes on.
I have to assume that your rear discs are in tolerance and have no big lip where they are worn – also that the pads are either new or in good condition if being re-used.
The piston should be well retracted into the calliper when it comes ‘out of the box’, but if not you will need to push the piston back into the calliper – remembering that it will need to be rotated as it goes back in order to override the screwthread. It will be quite tight and should require a fair bit of force to move it, but is achievable with a selection of screwdrivers and levers. (Right and Left callipers work in opposite directions).
Okay then, with the pads fitted in the calliper, slip the calliper into its correct position and loosely secure with the 2 x 18mm bolts provided.
Connect up the hydraulic hose, using 2 new copper (Dowty) washers and banjo bolt – torque up as stipulated (stainless ones are different to mild steel, so I ain’t going to publish the numbers!), making sure the hose is not unduly twisted.
Now is the time to bleed the calliper – the bleed nipple is 10mm spanner size. I found that it needed a few goes to remove all of the air from the system – if you lightly tap the proportioning valve (with a small spanner – not a hammer!) as you go it may help dislodge any bubbles in there. Likewise, tapping the calliper will help to dislodge any bubbles in there.
If you can’t get a good pedal try removing the calliper bolts and moving its position around whilst bleeding – it will help air bubbles to rise and escape from the bleed nipple. If using old (thinner) pads, it may be necessary to wind the piston out (quarter-turn at a time) before you can get the pads to touch the disc with a full pedal travel – this is not a problem/defect just makes the final adjustment a bit easier!
Once you get a good foot pedal, it’s time to set up the handbrake.
In an ideal world, the handbrake levers will only move a small amount between their cast ‘stops’ on the calliper and the position where the disc is locked up – if you are in this position then you’ve been lucky/done really well – have a beer and relax!
In reality you will probably find that you need to fully operate the handbrake levers for their full travel (hence not fitting the springs earlier!) in order to operate the adjusting mechanism and get it close.
Once it seems that there is no further adjustment being done when you move the levers, you’ll probably find there is still about a 40 degree (or more) rotation of the lever before it locks up. If you re-fit the springs and then the cables at this point you will find that you can pull the handbrake up for its full travel on the ratchet and still not be able to hold the car still.
So before you do that, slip the calliper bolts out and lift it away from the disc slightly. Now operate the lever a bit and watch the piston/pad move about a millimetre or so – when you release the lever, the piston will stay out where it moved to (hopefully). Now slip the calliper back over the disc and have another go. A couple of goes and I ended up with a suitable adjustment whereby the calliper only just went over the disc. It still turned without binding and only a slight movement of the lever locked the wheel up.
Now is the time to tighten up the calliper mounting bolts and torque them up. There is a discrepancy in the Workshop manuals as to how tight they should be – one section (Rear suspension) says 100 – 110 Nm, another (Brakes) says 90 – 110 Nm – so I went for 105!!!
Re-fit the return spring (a bit of a lever with a screwdriver and a pair of pliers got it in straight away).
Refit the cables by pulling the levers round a bit and slipping the cable through the fork. The two cables are joined together at the handbrake lever with a pivoted ‘compensation’ link, so if the second one will not fit onto the calliper, whilst allowing the spring to pull the lever back against its ‘stop’ position it may be that they need adjustment inside the car…….
Last bit then, as per the manual – adjust the cables……
Except, it isn’t quite as easy as it looks in the manual …..
Once you lift out the ‘oddments tray’ from the armrest (held by 2 small screws), you’ll see the cables – however, the nuts/brackets to adjust them are under the actual armrest fixing, so you need to undo the 2 cross-head screws which hold the rear of the armrest and lift it up a bit. You can now (just) get a couple of 17mm open ended spanners onto the adjusting nuts and set the cables to the correct length (just take up the slack, but no pre-tension on the cable).
If it has all worked out okay, you will have a solid foot pedal, and a handbrake lever which will lock up the wheels with about 4 clicks of the ratchet.
Equally importantly, it will release when you lift up your foot or take the handbrake off!