The topic of the rear brake dust seals has come up here and there. Both myself and the late, great Gordon Raymond have been discussing and researching the topic and we are ready to report our findings. Ok, so he’s not dead yet.
We know of three possible sources for these dust covers: AlfaStop, OKP, and Moss Motors. It has been pointed out that the dust seals for the TR6 were the same. Gordon already had a set from AlfaStop, and I already had a set on the way from OKP when the news about Moss Motors hit the press. So, why not just get a set from Moss and compare?
When I had the sets from OKP and Moss in-hand, I sent them to Gordon for a side-by-side comparison. He has graciously taken some detailed pictures of the versions, and I will post them here.
From what I can see, AlfaStops’s version is the highest quality. It even has the Girling script molded into it. The OKP version is next in line followed by the Moss version. As you might guess, the quality follows the price. Not to worry, I can’t see why any of them wouldn’t work just fine. Personally, I would choose the Moss version since all I am after is a nice driver. If you are creating a prize-winner and you know that some Alfa snob is going to crawl under your car with a magnifying glass looking for the Girling script on your brake dust cover, and that is your game, then the AlfaStop versions are the only way to go.
Gordon wrote a little about the quality of the materials used. With his permission, I am reprinting it here:
Christian’s (OKP) are closer to the OEM than the Moss. The moss rubber is softer, and smells more rubbery than either Christians or Tony Stevens, Girling marked dust shields. The Moss is a little more pliable than the Girling marked, but seems the same as Christians.
You probably need to check with a chemical engineer, but many years ago, I was told, (correctly or incorrectly) that rubber that smells rubbery, has more volatiles available to oxidize, and will age more quickly (harden) than non smelly rubber. Ozone is very bad for rubber, and attacks smelly rubber more than non smelly. I also understood that all the rubber treatment products, like Armor All, were intended to seal and protect the rubber from ozone. Race car tires smell less and less as they age and get harder. Gummy slicks are really stinky when new.
The other side of the argument goes like this. Non smelly rubber has aged, lost its volatiles and begun to harden.
Not being a chemical engineer, specializing in rubber, I'm clueless. I have a set of Tony (Alfa Stop) Girling rubbers. If I did not, I would probably use Christians, as the look more like the Girling than the Moss. The Moss, having the most odor, might be either the very best, the worst, or the same as the others as far as service life is concerned. Chemical engineer required.
Big problem is once installed, and the brake system bled and functioning, to replace a bad dust seal is not only a mess, but can result in loss of paint on backing plates if brake fluid contacts them when disconnecting the hydraulic lines. This is MY reason for not installing my Girling set.
At this point, I became a little concerned for Gordon’s health. I wrote him and pleaded with him to stop sniffing the “volatiles.” I even threatened an intervention.
I kid you not; this is what he replied with:
Daaaahhhhh... Um .. WhAt??
Seriously, we are all indebted to Gordon on this website. He does outstanding restoration work. If you have carbs, oil pumps or water pumps that need rebuilding, it is my opinion that you are wasting your money by having anyone else do it. Moreover, he is the only one that I know of that can revive 750 and 101 oil pumps by machining them to accept 2liter oil pump gears. So, send your stuff to him. We will work on getting him to wear a respirator while using the parts cleaner. Baby steps, baby steps.
Here is a link to the dust shields on Mossmotors.com
MossMotors.com - Restoration Parts And Accessories For British Cars
Look at #59.