Brakes again

[1958trebor]

Hi all, I would be grateful for your usual expert advice. I have a '54 series 2 which has been heavily modified over the years and its 24 (at least) previous owners. The front brakes are now the later, larger drums, which I think are 8". The problem is, every time I fit new shoes, they have to be wound out to the last click of the adjuster before they bite. Is there a part such as a shim that has gone missing or are modern shoes too small? I always specify to the supplier that my car has later brakes i.e 1098 and they always say that they have supplied the correct shoes. The drums are in good condition without a huge amount of wear. Also the car suffers from variable brake pressure. Sometimes there is a firm pedal, sometimes it's soft. There is no pattern and I have bled the brakes and checked for leaks more times than is sensible. I am beginning to lose heart with this car, it's becoming potential danger. Having spent the best part of four years trying to sort out the brakes, it may be time to steal the reg and scrap the stupid piece of ****

[kennatt]

when you fit 8 in drums there is also a need to fit the larger cams,or you will always need to wind them right out .this also means that with the slightest wear on the shoes the brakes go out of adjustment.make sure you have the 8 in cams fitted,also old cams wear and can slip on application of the brake ,also loosing adjustment.hence the classic ,having to pump the pedal to get it firm.One cure ,that many have done if you have a welder,is to put a stroke of weld on the non cam of the shoe making them slightly longer.

[Nickol]

Check the condition of the hoses, if not new. Get someone to put pressure on the brake pedal and check for any Expansion of them under pressure - there are three : i.e do not Forget the felx hose at the rear. Replace if necessary.

[philthehill]

You do need to confirm what front brakes you have fitted to the car.
The car could have been fitted with the Wolseley 1500 brakes which look identical to the Minor but at of a slightly larger diameter.
A photograph of the brakes with the drums off and a confirmation of the brake drum size would be especially helpful.
Comparing the 7" and 8" snail cams the main difference is the size/diameter of the shaft through the centre of the snail cam.
The 8" brake snail cam has a larger dia shaft to accommodate the extra rotational forces acting on it generated by the additional power of the 8" dia brakes.
The lift of the snail cam is the same whether it be a 7" or 8" dia drum.
Because of the difference in shaft diameters the 8" snail cam is not suited to the notch in the 7" brake shoe and the smaller shaft diameter of the 7" brakes is not man enough for use with 8" brakes.
The small difference in shaft diameters will have little influence on the ability to adjust the brakes.

[Dogsdad]

Bull Motive sell a larger cam and mask which should solve your problem.
It did for mine.

R.M.

[philthehill]

http://www.morrisminorspares.net/shop_item.php?ID=5276

Bull Motif Pt No: FBK110

Appears to give a larger adjustment than the standard item.

[1958trebor]

Thanks Guys, I will order the parts tomorrow.

[philthehill]

Whilst the parts listed above may or may not get over the problem of brake adjustment the underlying problem has not been identified.

[kennatt]

[quote][/Bull Motive sell a larger cam and mask which should solve your problem.
It did for mine.
quote] interesting info phill,just thought they were larger,but the ones I was supplied with by Tom Roys were distinctly larger ,and cured the same problem as posted, must be a regular available alternative cam.

[philthehill]

I came to the conclusion that the snail cams are physically the same except for the shaft diameter by comparing a couple of the 7" brake snail cams and masks with a couple of the 8" brake snail cams and masks both assembled and dis-assembled. The parts examined are genuine OE BMC parts.
Note:- The 8" snail cam and mask are used on the rear brakes of the Wolseley 1500, the Minor 8" front brake drum is also used for the brakes on the rear of the Wolseley 1500 but of course with only the one cylinder/one leading brake shoe arrangement.

[Dogsdad]

Phill, I can assure you that the snail cams supplied as extra-large by Bull Motif are larger than the usual 8 inch
cams.
The cam is larger although the shaft is the same diameter ( 10mm ).
The need for these is hard to pin down.
Worn brake drums? Mine don't seem to be.
Pattern brake shoes slightly wrong size? Copies of copies of copies ?
Pattern brake cylinders not quite right size? Again copies of copies of copies?
I suspect a combination of all these.
It must be a common problem to warrant production and sale of these large cams which seem to be the only new ones Bull Motif now supply.

Anyway the adjustment is now possible.

Richard M.

[philthehill]

Richard
Many thanks for the details.
I also have no idea why the larger snail cam is required/produced - perhaps all will become clear in time.
Phil

[shoebone]

Drums may of been skimmed by one of the 24 previous owners

[philthehill]

If the drums have been skimmed to such a degree that they need oversize snail cams the drums should be replaced as the shell of the drum will have been reduced in thickness by some serious amount; and having checked the thickness of a pair of 8" drums there is little thickness to start with.

[Dogsdad]

24 previous owners?
My car has only had 14!
I suppose skimming is a possibility although there seems ample thickness to the drum.

Richard M.

[1958trebor]

Hi, I'm back again with another question about the brakes on my series 2. Since I last posted I have replaced with new parts; Front and rear drums. Front and rear shoes all round. All wheel cylinders. All adjusters. N/S handbrake cable. Small springs in rear hub. Completely bleed fluid. Renew flexis and fit copper pipes. Test master cylinder for leaks etc.
So now I have a new problem. Although the car pulls up straight and has passed its MOT, as I cover the brake pedal and begin to apply pressure, there is a violent shuddering from both front brakes, enough to set my dash-cam to 'Lock' as if it's been in an impact. As i press harder and actually apply the brakes, the shuddering stops and the car pulls up straight. It feels like the drums are warped but they are from a well known supplier and are new. I have checked to see if the tyres are warped or deformed, if the wheel bearings are loose, even if the steering column is loose. Nothing! It does not do it when first setting off and the brakes are cold but within a mile or two off we go again. I had a problem with the rear brake not coming off after application of the handbrake but that seems to have settled down.I really don't know what to try next.

[ManyMinors]

I had a similar issue after fitting brand new drums to my car. I sourced a good secondhand pair in the end which cured the problem and sent the new ones back to the supplier.

[philthehill]

Did you chamfer the leading edge of the brake shoes?

Having the chamfer helps to lead the shoes to the drum without chattering.

[1958trebor]

OK I'll try that. There is a small amount of squeal but I put that down to bedding in. The car has now done 200+ miles so I would have thought it would have settled down if that was all it was.
Present wife available for assistance tomorrow, so she will be on pumping duties!
(phnar phnar!)
Sorry, very 'Vis' circa 1980s