Could use some help before I visit repair shop re a nail in a tire

[djp]

I think the best solution is to stick a buffer on the back of the pad in addition to using those strips on the caliper. I'm using the caliper strips with red goo right now, they help a bit but don't entirely eliminate the rattle. I've also found the red goo is more effective if you dry it with a heat gun before reinstalling the pad.

Rattles coming from brakes

 

[dpeilow]

When you say red goo, is it "CRC Disc Brake Quiet"?

 

[djp]

When you say red goo, is it "CRC Disc Brake Quiet"?

Yes, that's it. I've had to reapply it a few times and my rear pads could use another coat again. Next time I pull the tires off I'll use a rubber buffer on the back of the pads instead.

 

[dpeilow]

By the way, I came across these. I wonder if they would work on the Roadster in lieu of not having the Tesla lifting adapter?

Lift pucks (Elise / Exige) [EELPC] - €22.00 : Elise Shop, Performance parts for your Lotus Elise

 

[dpeilow]

Right so I ordered both the Elise rubber pads and the red goo.

The pads came with no instructions and it was really not obvious where to fix them to the calipers.

A local Roadster owner came over to assist and we decided to go with the red goo. After applying a layer as directed and curing it a bit with a hair dryer, we replaced the pads and tested it. I did a couple of hard stops just to get the calipers to bite. The pads seemed more solidly held.

But it's made zero difference to the rattling. We both agree it's coming from the left but it sounds like inboard of the wheel.

 

[wiztecy]

Looks like your CarboTech pad has some sort of metal shim on it. My AX6's never came with that, I don't think the 1521's came with that unless they're now adding it as part of the brake package. I know Dave @ CRF who made the two piece rotors did discuss the rattling issue with them over at CT, so possibly they're now adding shim to help eliminate the rattle. Unless it was there from the original brakes, possibly I tossed mine out back at 6k miles.

Anyways, with the wheel off you can always verify the rattle by grabbing the top of the pad and try moving it back and forth towards the inside of the car then to the outside.

 

[djp]

The rubber buffers go on the calipers above and below the brake pads.

Another thing you can try is to use your fist or a rubber hammer to bang on the underside shroud. I've found a few loose bolts in there that were bouncing around.

 

[wiztecy]

Blackwatch racing (which I recommend) in the USA has the buffers. Here's below they say and why I presume the CarboTech pads rattle. As BWR mentioned, Lotus/Tesla already put a buffer there so don't be surprised as i did when you see one but can wear or might not be as thick as you ideally want it in order to take up the space between the metal of the brake backing and the caliper:

Anti rattle brake pad buffer

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Alleviates brake pad rattle.

If you compare most high performance brake pads to original pads, you will find the backplate of the pads to be smaller on the high performance items. The reason for this is because high performance pads are designed to be used at extreme temperatures. The backplate of these pads expands further then what you'd expect with pads for road use.

Besides that, as the Elise or Exige is a relatively light weight car, the temperatures of these pads normally don't go up as far as when being used on heavy saloon cars. The backplates won't expand that much and you might experience an annoying rattle from the front brakes while driving your car.

Lotus has anticipated on the above and stuck small patches of rubber inside the front brake calipers. This rubber tends to wear over time, or even completely disappears.

Our adhesive anti rattle brake pad buffers are a high grade, adhesive backed material which simply needs to be stuck in the same location as the original buffers. They're very easy to install, especially when you're replacing the brake pads.

------------------

 

[strider]

My 1521's have the metal plate. I used the red goo on mine and they don't rattle. The key is to follow the instructions exactly. They say to spread the goo and then wait like 10 mins for it to set up and then install the pads. If you don't wait the goo will just squish out when you install and won't do its job. I have thousands of rattle free miles on mine.

 

[dpeilow]

@wiztecy that text is cut and paste on every website I have seen selling the pads. They really need to supply the drawing of where to put them with the product. I will be making that feedback.

@strider I might reapply a little more of it. The only instructions with the bottle were to apply 2-3mm. We used a hairdryer as per the recommendation above, but were probably too impatient as it did spread a bit on putting the pads back in.


Yesterday I doorstopped the local Lotus dealership. I got chatting to a tech as I wanted to know if they also needed the lift adapter. He said no they don't and gave me a copy of the page from the Elise manual that just shows normal jacking points covered by the undertray underneath the engine bay.

He also said that when he has heard the same rattling sound on Elises, it is normally cured by bending the spring clip to create more pressure on the two pins that go through the pads and calipers.


Interestingly on the way back from there to my place (about 10 miles) the noise almost completely stopped. It had become noticeably cooler and I wonder if there is a temperature element to this? Maybe the red goo cured better.

There was a thread on here about someone possibly CNC machining a batch of them to sell, but as far as I know, nothing came of that.

I popped back to the local independent garage down my road. The other brother was in and also super interested in the car so I gave him the tour.

We chatted again about this lifting adapter issue. I think it would be a good idea to resurrect this CNCing an equivalent part idea. If it allows a local place to fix a minor issue that might not even be safe to take 100 miles to the nearest SC, I think that is worth having. Who would be in?

 

[wiztecy]

Here's the thread on the lift adapters, best to wake that thread back up to get the project going again:
Simplified Roadster Lift Adapters

 

[Habious]

I think it would be a good idea to resurrect this CNCing an equivalent part idea. If it allows a local place to fix a minor issue that might not even be safe to take 100 miles to the nearest SC, I think that is worth having. Who would be in?

Here's the thread on it...

Simplified Roadster Lift Adapters

I'd be interested.

 

[hcsharp]

...
We chatted again about this lifting adapter issue. I think it would be a good idea to resurrect this CNCing an equivalent part idea. If it allows a local place to fix a minor issue that might not even be safe to take 100 miles to the nearest SC, I think that is worth having. Who would be in?

I'm NOT in. I started to make my own before discovering the two shops that I visit could not use the adapters if I had them. One shop has a lift that doesn't allow you to use lift adapters (no holes). The other shop can't get its arms low enough to fit under the adapters once they're in place. Even if you find a lift that might work, there are 3 different common sizes for the post on the bottom of the lift adapter. So we would have to make 'adapters' to go along with our lift adapters. I've started using 4 x 4 blocks. You just have to make sure it's not positioned under the brake line that passes next to where the lift adapter goes.

 

[Stefan T]

I have used 4x4 wood 160-165mm long when i lift my roadster on my lift

 

[dpeilow]

We are looking into 3D printing some adapters. That way we can more easily customise the lift side to whatever you or your local shop have.

 

[dpeilow]

So after a week I decided to redo the anti rattle compound and leave it longer to cure. Pushing the pad back in it still scraped on the caliper but was much better than the first attempt.

I hear rattle from the left side very rarely now but interestingly the right side started it, although infrequently.

The car passed the annual MOT safety check yesterday so I hope that means other joints are ok.

 

[Mark77a]

Just fixed annoying brake rattle.
Turns out it can be fixed by ... wait for it ..... the anti-rattle spring plate

See the little hook along the top of this plate - which hooks onto the top pin - call it a
Also see the horizontal wider bit below the hook - call it b

b fits under the extension of the backing plates, around top pin hole, that sticks out backwards.
The pin holes in back plate are much bigger than the pins so the pad can move, expand and be pushed UP against caliper on braking.
When the spring is new (or tweaked), b holds the pads higher, nearer to the top surface inside the caliper which they are pressed against on braking. This also means they dont rattle - which is the pads especially when hot / expanded bouncing on the lower surface of the caliper.

The cure is: buy new anti-rattle spring plates AND/OR make sure they hold the pads HIGH in the caliper (braking position).
I found my 26K old anti-rattle spring plates allowed ~1mm free play which let the pads bounce about enough to hit the lower surface of the caliper. The free play downwards, can be reduced by reducing the distance between a & b.
I found the easiest way to do this was the very slightly squeeze the hook, reducing its inner radii, and so reducing the a to b gap.
This simply raised the pads by about 0.5mm, without adding any more friction or restriction in movement.
The pin holes in brake back plates are now held so that pins sit below centre - as pads sit higher.

After getting annoyed by this rattle coming and going, and loads of surprising miss-info 'bum-steers', on various forums etc. this worked.

What bends the anti-rattle plates, so they need renewal/tweaking, and make the rattle worse, is braking in reverse, especially when pads are cold, or slightly smaller higher performance pads (which might be smaller for wider expansion tolerances), this pulls the pads DOWN, stretching the anti-rattle plate in the wrong direction, hence allowing the pads rattle on the bottom surface.

Please note: all "you do at own risk" provisos apply to these notes.

 

[dpeilow]

I forgot to mention that I also bent this to put more tension on the locking pins.

 

[Mark77a]

I forgot to mention that I also bent this to put more tension on the locking pins.

Too many J turns then ?

 

[wiztecy]

Mark.... Is this just me or does it look like your arrow in the metal spring plate is pointing the opposite direction than what's pictured in the schematic you supplied? I haven't verified with my setup (been a while since I pulled my pads off completely) or anywhere else to verify which direction it should be placed and if one side is opposite of the other, but just an observation....

Looking at it it appears that clip is longer on one side, so it may have clearance to fit only one way in the caliper. That does appear to be the case, fits only in one orientation to clear the pins.

Looking at other places online I find the arrow pointing the same way you have yours. So what does that arrow indicate? Up, such as pointing towards the sky and not the ground?

Lotus Elise Maintenance, Front Brake Pad Replacement