7 replies to this topic

[Rata Road]

1970 stock drum brakes with car been in long time storage, brakes havent been used for over 15 yrs.

 

One front cylinder had leaked, rest of brakes, cylinders/shoes etc look newish to the eye.

 

4 new cylinders fitted to front end. The right side front (that had the leaky cylinder) had the shoes and drum cleaned as best you can.

 

Removed master cylinder, drained, Refitted and bled entire system until new fluid at all corners.

 

It still takes one pump to get full pedal. I am sure there is no air in system.

 

Front wheels will lock via the adjuster so set them correctly but rear the wheels will NOT lock via the adjuster. However if I pull the handbrake on 3/4 way it removes the need to pump the pedal suggesting the rear brakes are the cause of the pump.

 

The rear shoes look meaty but I suspect the rear drums have been turned and perhaps standard shoes don't reach correctly. Before I order new parts from the other side of the world can you please advise.

 

1. What is the inside dia of a standard brake drum

2. How thick (including the metal) is a new standard rear brake shoe. I seem to remember you could order oversize brake shoes to fit a turned drum.

 

With these measurement I can judge if either new shoes/ new drums or both is needed so I can get a tight adjustment and hopefully remove the pump the pedal situation.

 

Also I notice the car pulls left slightly if I pump the pedal once and brake firmly. I suspect this is due to an oil soaked brake shoe on the right front still containing some fluid.

Do you suggest replacing the front shoes will eliminate this or perhaps a good drive up and down a steep hill with lots of firm braking to try and burn the fluid out/bed the shoes in etc?

 

Thanks in advance

 

[Miki Leyland]

Once the shoes have been in contact with hydraulic fluid it is nearly impossible to clean them properly, so I'd go for a new set of shoes and flexible brake hoses as these can be in very bad shape without any sign from the outside.

When adjusting the shoes you have to let them drag a bit with the drum and never let them spin freely. This is normally achieved by releasing the square nut 1/4 of a turn from complete lock.

[Ethel]

https://www.minimani..._Brake_Data_591

 

In my experience after market linings tend to be a tad on the large size, if anything. It doesn't take long for drums to wear a lip on the edge where's no friction lining contact, that's usually a good enough wear indicator. Drums rarely need replacing.

 

You could be right on the handbrake, but it could also just be compensating by taking up the slack from elsewhere.

 

Apologies for the egg sucking advice, but the shoes are fitted with the leading edges leading? Also, turning the front adjusters  the same as the wheel rotation gives a little bit more control of the adjustment.

[Rata Road]

Thanks Guys.

There was no ridge on the drums that's why I thought they may have been turned. I've done thousands of miles in early Land Rovers and it was common to get the drums spun and oversize shoes fitted, perhaps not so much in a small mini hub.

 

I went for a drive after I posted today and gave the brakes a heavy work out on a steep hill, both forwards and backwards with strong braking action about 20 times. I notice going backwards the handbrakes stops the car well but the footbrake doesn't do as good a job?

 

The result is they no longer pull to the left even under firm braking but when I do a lock up test on gravel at slow speed only the front left skids so I suspect your right about the oily shoes on the RF.

 

Also now pulling the handbrake on doesn't reduce the need to pump them up so I plan to adjust the front brakes again and hopefully get the result I'm seeking. No need to adjust the rear as I set them to max out before I fitted the rear drums.

 

No I didn't replace the flexi hoses.

 

Ethel to be honest I didn't check to see if the leading edge was leading as it looked to me the spring/adjuster holes would only allow them to be fitted one way, was I wrong?

 

Thanks

[sonscar]

Apologies if you know this but did you slacken off the handbrake before adjusting the rears?then readjust it.Steve..

[R32Egor]

HI,

 

Great video from these guys in Canada about adjusting rear brakes - I did it the same and perfect

 

 

[Ethel]

Yes, it's only the rears you can get the shoes back to front on.

 

Foot brake (on the rear) is via the pressure limiting valve while the handbrake isn't. Of course, you also have only one leading shoe out of 4 when you're going backwards too.

[Rata Road]

Good feedback thanks.

Today I removed all drums.

Rear shoes are fitted correctly but hadn't been off by me. Thanks to that brilliant video that R32Egor posted above I learnt that if I kept winding the adjuster they would tighten up and also to set them firmer than normal. I did this and got them set correctly hence no need for new shoes or drums on the rear!

Front brakes were in correctly, while I had them off I cleaned the oil stained shoes again with turps, then buffed them with a wire brush on my drill, hand buffed with sand paper and blew them clean. Gave the drum a sand also and now the shoes look the correct fawn colour. Put the drums back on, adjusted up and road test.

 

I now have a full pedal...excellent!

Gave them a good downhill workout again. Still have a slight pull to the left under hard breaking so will order a new set of shoes for both sides just to be safe. Interesting that when I do a slow speed slam them on on gravel both front wheels lock up now.

 

Once again guys thanks for your guidance.