Is this right?

[MorrisJohn]

This is a genuine Lockheed mask (8”) with what is supposedly an adjuster cam for 8” brakes. The cam looks smaller than I remember. Does this look right?

It’s maybe just me, but I thought the cam should be a little bigger than it appears?

[unclealec]

I'm watching this with interest. It is just this sort of post that will help me short-cut my way into Minor knowledge. General principles fine, but every make/model has its idiosynchrasies and I am too old to find out the usual way - make a mistake, remember, and don't make it again!
I would have thought that the indentations on that camwheel are almost worn off, so it will be interesting to hear from the experts.

[MorrisJohn]

I'm watching this with interest…

I’m pleased others find this sort of question useful too. I know the adjuster cam teeth are meant to be smooth and that, generally speaking, they don’t wear out. According to ESM the masks are more likely to wear over time.

As a side note, the Lockheed mask in the photo is new old stock.

[philthehill]

The indentation in the rim of the snail do not have to be fully shaped to hold. As they are the snail is perfectly ok.
The main difference between the snail adjusters of the 7" and 8" diameter brakes is that the 8" adjuster is slightly beefed up but overall size is the same. If I can lay my hands on the 7" & 8" snail adjusters I have spare I will photograph and post on here.

[MorrisJohn]

The indentation in the rim of the snail do not have to be fully shaped to hold. As they are the snail is perfectly ok.
The main difference between the snail adjusters of the 7" and 8" diameter brakes is that the 8" adjuster is slightly beefed up but overall size is the same. If I can lay my hands on the 7" & 8" snail adjusters I have spare I will photograph and post on here.

Brilliant - thanks again Phil.

[unclealec]

Great. Next time I am in my workshop I will eagerly examine the adjusters from my van rear brakes and ponder.

[geoberni]

It's a little hard to tell with it in that position.

Last summer I fitted 8" Cams to my car front brakes because I found that it had 8" brakes with 7" cams!
As a SII, it originally had 7" all around, but a PO had fitted 8" to the front but didn't fit the correct adjusters.

I've just made up this comparison image by lifting images from a certain interweb auction site.

Brake Cams.jpg (107.13 KiB) Viewed 825 times

[MorrisJohn]

It's a little hard to tell with it in that position.

Last summer I fitted 8" Cams to my car front brakes because I found that it had 8" brakes with 7" cams!
As a SII, it originally had 7" all around, but a PO had fitted 8" to the front but didn't fit the correct adjusters.

I've just made up this comparison image by lifting images from a certain interweb auction site.

Brake Cams.jpg

If what Phil says is correct (I believe him when he says both cams are the same size), then it shouldn’t matter if 7” cams are fitted with 8” drums?

Both should give the same shoe to drum adjustment?

[geoberni]

Phil is only right in that the cam is the same size.
That's probably the same mistake the PO made in not fitting the right ones to my car years ago.

If you look at the centre section of the 2 adjusters, the 8" is fatter than the 7".
So it's not the cam size that's different but the 8" brake shoe is sitting on a fatter cylinder.
If you fit a 7" adjuster, the shoe is sitting slightly lower, so overall you don't get the same amount of adjustment.

You're using some of the adjuster range of movement to raise the shoe up to the place it would have been if you had the right adjuster to start with....

[MorrisJohn]

Ahhh!! It all makes sense now