Richie's Mk1 Restoration - Page 21

Michael R. · #**601** 03-07-14, 02:19

Why was one shoe worn?
With the expander assembly free to float, the shoes should have self centered.

RichardT10829 · #**602** 03-07-14, 09:09

One adjuster had stuck so one shoe was contacting more than the other

RichardT10829 · #**603** 03-07-14, 14:47

Does anyone have a datum ref regarding the ID of the drum when new ? And the thickness of the shoes when new ?

rob love · #**604** 03-07-14, 15:34

Brake lining dimensions are given at the back of the Brake section in UC-F1 as 3/8 thick, 2-3/4 wide, 12-1/4 long.

I have had sets bonded before. If you have your drum turned by a known diameter, you can have an equal thickness of shim installed under the lining to get the proper arc, but in that case you will also have to rivet as opposed to bonding the linings to the shoe.

Personally, I have always turned the drums clean, had the shoes relined, then had the shoes ground so they fit into the arc of the drum. They will still need to set themselves in to some degree, so don't expect perfect brakes right off, and expect to have to re-adjust them a time or two as they fully set in.

The braking/turning power of a clean set of drums and shoes will not be experienced with grooved drums. Surface area is the key.

Lynn Eades · #**605** 03-07-14, 15:35

Rich. theres no spec in my book so try this. I think the original lining thickness was 3/8" So take the curve of a shoe with no lining. Plot a circle from it, adding 2 x the lining thickness, which should give you a nominal size Something like 15" From this and the unworn lip inside your drum, you should be able to make an educated guess at the original drum dia, and how much might already have been turned from your drums. Probably Richard F. is on the nail when he said it might be original dia. plus wear.

RichardT10829 · #**606** 03-07-14, 15:44

Cheers guys, just at work trying to organise stuff so don't have my book to hand

Lynn Eades · #**607** 04-07-14, 00:29

Rich. be aware that when I said 15'', I should have said " a std nominal size" (what ever it is) I don't have one to measure, here.

Richard Farrant · #**608** 04-07-14, 00:48

Quote:

Originally Posted by Lynn Eades

Rich. be aware that when I said 15'', I should have said " a std nominal size" (what ever it is) I don't have one to measure, here.

The drum inside diameter is 14 inches. (taken from Canadian manual). Cannot recollect what was removed to clear the wear on the Scout, but no doubt got it here on my notes somewhere. The machining of drums was done by a local machine shop and shoes were relined by a brake specialist, I informed them of the diameter difference and they finished the shoes accordingly. A bit of hand fettling of linings to ensure shoes fitted the drum snuggly, as I know that modern linings will not bed in quickly and this proved worthwhile on the first test run of the Carrier as I understand.

regards, Richard

chris vickery · #**609** 04-07-14, 01:08

One website I visited recently on this issue suggested that lining are available in a variety of widths and thicknesses by the 1/8".
Since military drums are so heavy and likely original diameter, a quick turn with as minimal skim as possible should even them up. If originals were 3/8" maybe it is possible to use 1/2" linings by removing adequate material to suit.
I had CMP brakes relined this way with lots of material left on the drum.
When you consider how thin modern drums are, the old military ones are built like tanks. Also, the vehicles we are putting them on are not seeing service conditions loaded to the max or overloaded even. For something like a carrier I personally wouldn't get overly concerned as long as you get new shoes to match up to freshly turned drums.

Ben · #**610** 04-07-14, 16:35

What Richard said. They were spot on!

RichardT10829 · #**611** 04-07-14, 16:46

how did you hand fettle them ? sand paper then offer them into the drums ?

Richard Farrant · #**612** 04-07-14, 20:13

Quote:

Originally Posted by RichardT10829

how did you hand fettle them ? sand paper then offer them into the drums ?

You've got the picture ! Making sure they touch all round and don't rock.

RichardT10829 · #**613** 05-07-14, 21:40

Well had a busy day at work, then came home and broke the tracks, and took the drums off, here are my findings:-

Left drum (the problem drum)

RichardT10829 · #**614** 05-07-14, 21:45

Right drum:-

RichardT10829 · #**615** 05-07-14, 22:13

If the drums start at 14" looks like they have been skimmed once and had an 1/8th taken out. Yet the shoes have no shims underneath ? So if I was to get another 1/8 taken off to correct the drums do I need to factor in the previous metal takenout plus what I have taken out this time ?? How thick do the shoes need to be then ?

Richard Farrant · #**616** 05-07-14, 22:36

Quote:

Originally Posted by RichardT10829

If the drums start at 14" looks like they have been skimmed once and had an 1/8th taken out. Yet the shoes have no shims underneath ? So if I was to get another 1/8 taken off to correct he drums do I need to factor in the previous metal takenout plus what I have taken out this time ?? How thick do the shoes need to be then ?

The Canadian manual UC-F1 quotes 14" so looks like the drums might have been skimmed. Bad practise to shim between lining and shoe, best solution is thicker linings, you know the standard lining thickness from the manual. The brake reliners will work it out from there. They can profile to fit the drum.

I am surprised you never inspected the brakes earlier on, a crucial area, being steering and brakes. Check the hub bearings for pitting too, due to condensation and standing around.

RichardT10829 · #**617** 05-07-14, 22:51

The bearings are all good, have had them all out and cleaned then.

I knew the drums were pitted but thought there was little I could do about it...

kevin powles · #**618** 05-07-14, 23:02

Rich, your drums look quite thin, as I recall I think there is a tell tale chamfer on the inside which is there on new drums and gradually wears out or is lost with remachined. What I would do is get some new shoes in before next week and take it easy at the show. I have a set of drums true and smooth available but will require oversize shoes, we can talk about this after the show if you are interested.

Your sprockets look like they have seen better days. Something to look at later.

Kevin.

RichardT10829 · #**619** 05-07-14, 23:06

Cheers Kev.

And there was me thinking that there was a fair bit of meat left on them, just over half an inch.

Lynn Eades · #**620** 06-07-14, 02:55

Richard F. has it right. The brake shop will take the minimum required out, and thickness the oversize linings by radius grinding them to fit the drum.
Check your wheel bearings carefully, fit new inner hub seals, and make sure you remove the tin shields from the axle (6 castle nuts each side) clean inside them, and make sure you clean out the "tell tale" holes, through the backing plates. This shows you if a hub seal has started leaking, so that you can catch it before it gets to the new linings.
Note. the rust pitting has happened to your drums where the linings don't touch them, when your carrier has sat for 25 years at a time. This rough bit tears your linings to bits.
While you are waiting for the drums and linings to get done, I would strip, clean, and re assemble your bisectors (making very sure you assemble them properly. If you get the wedges in the wrong way around, very little travel will be the result. Use a good grease, and be very careful with the alloy housings
You might advise the brake people that this job would maybe be better done with low speed (woven?) linings.

eddy8men · #**621** 06-07-14, 11:37

rich you could just put the good shoes on the leading edge and the bad ones trailing, then do war and peace and worry about faffing around getting it right after the show when things have calmed down a bit and are back to normal.
I think I have a set of good spare shoes in a truck axle I could bring to the show as a plan B.
the most important thing is to not get too caught up with getting it perfect and just enjoy the show.

rick

Lynn Eades · #**622** 06-07-14, 11:41

Rick, the shoes are not the same as any truck ones as far as I know.

eddy8men · #**623** 06-07-14, 11:46

ajmac might know, I have a rear hub set from a fordson 7v axle that I bought for a loyd project that never happened

RichardT10829 · #**624** 06-07-14, 14:10

Well it's do or die for me, any pads that go in those drums as they are will be destroyed rather quickly... So as long as the company can get the shoes turned around in time we might yet win...

The drums look like they will take 1/16 to make good, that added onto what has alread been taken off will mean the shoes need to be 1/4 over sized. Looking closer at the shoes that are in, they have a shim behind them which for the better part is heavily corroded.

Stress is through the roof at the moment everything is prepped up for Monday... Found out last night my engine covers won't be done either which has been a kick to my guts as I won't have time to make any now....

Lynn Eades · #**625** 06-07-14, 14:57

Each step carefully after the last. Engine covers won't stop it going.
See you there!

RichardT10829 · #**626** 06-07-14, 18:22

Exhaust cans completed and fitted... Another job ticked off !

eddy8men · #**627** 06-07-14, 22:33

rich i'll bring my engine covers down and you can keep them til the end of the show if you like

RichardT10829 · #**628** 06-07-14, 22:43

Cheers, Shaun is going to try and make some out of wood.. It's just to limit the Mount of dust getting into the engine area.

eddy8men · #**629** 07-07-14, 00:30

lol tell him not to bother, it's no trouble at all and besides I can say I got my carrier to the big get together (well a little piece of it anyway)

Marc van Aalderen · #**630** 07-07-14, 20:14

As the fan is sucking in all the dust anyway, sandblasting you along the way, it makes no difference to the amount of dust getting in your carrier. I know from last year and several years at the Hopfarm.