Drum Brake Ajustment

[GregFrench]

Used search, but my specific question was not answered.
My brakes have been slowly getting worse and in need of adjustment. Took it to the local brake place, and they adjusted the little thing through the holes on the backside of all 4 wheels. Drove it away, and had no brakes at all.
Took it back in, and this time they pulled the tires and adjusted the little turn-wheels inside the drum. Put the tires back on, and the wheels would spin a bit, but with noticeable binding. Drove it away, and the brakes still did not work.
My question is: what is the correct adjustment for these drums. Do they need to be loose, barely touching, or binding, and how do you know when it is correct?

 

[1phrogguy]

Hi,

Looks like you need to find another shop. Type this in search in this forum: drum brake adjustment

 

[amaurer]

Took it to the local brake place, and they adjusted the little thing through the holes on the backside of all 4 wheels. Drove it away, and had no brakes at all.
Took it back in, and this time they pulled the tires and adjusted the little turn-wheels inside the drum.

When they adjusted them through the holes they're turning the "little turn-wheels", both procedures are equivalent. You have to do this with the drums on, however, which is why the holes exist... I don't know what they were doing when they took the drums off, maybe making sure the adjusters were free.

Anyway, with everything on (drums, wheels), adjust each cylinder separately until the wheel won't turn, then back off two clicks. Some drag is OK, but you should be able to spin the wheel one full rev by giving it a twirl with your hand.

I think your shop is incompetant.

 

[Joe Egolf]

2xI think your shop is incompetant

 

[John McVicker]

If EVERYTHING else in your brake system is in good working order...this is what I suggest. You don't say what year you have but this assumes you have 4 wheel drums.

Adjust each wheel cly. seperately. 2 on each wheel if you have drums around.

A) Jack the wheel up. Adjust one cly. until the wheel has almost no movement. Then back off by 1 or 2 clicks at the most. One or two only...not 5 as the FSM says.
B) Then do the same with the 2nd cly on that same wheel. You are trying to get both clys. on that wheel to work in exact sync.
C) Do the other 6 the same way.
D) Go for a test drive and adjust again as needed...to correct any pulling etc.
E) Once you correct any pulling, drive a few miles without using the brakes. Pull to the side of the road & touch your wheels/drums. Careful they may be hot...maybe very hot. If so adjust back a click & go for another test drive. On this test hot drums are not good...but warm is ok.


There are a bunch of ways to do this & get good working brakes...this way works for me. No matter what way you choose, it is a very tedious procedure. But you can have great working brakes...even with 4 wheel drums.

John

 

[GregFrench]

Thanks. I have never had brake problems before. Last year they started to get weak and took it to be adjusted (at the same shop...I have used them for years, so this trip really surprised me). I'll do it myself tomorrow. From the way it sounds, I think they have them too tight. The brakes got worse the more I drove.
They took the drum off to see if there was anything they were missing in there, and to make sure they were turning them the right way.

 

[Pin_Head]

You tighten the cylinder until you can't turn the wheel any more. This is important to center the shoe in full contact. Then you back it off 3-5 clicks. It will still drag noticably, but this is normal and proper.

 

[El Cazador]

Jeff Zepp has a pretty good tutorial on drum brakes.

Land Cruiser Drum Brakes

 

[jimhendrixx]

Pin-Head has the right idea. that is how i did/do it on my cruiser.

 

[rusty_tlc]

You tighten the cylinder until you can't turn the wheel any more. This is important to center the shoe in full contact. Then you back it off 3-5 clicks. It will still drag noticably, but this is normal and proper.

Thats is the way, if that doesn't work you have other problems.

 

[lostmarbles]

.....Then back off by 1 or 2 clicks at the most. One or two only...not 5 as the FSM says.........John

......Then you back it off 3-5 clicks..........

I'm with John in that I believe any more than 2 clicks is too much.

This is true for my 1979 forty anyway.

Oh - And I like to "centre my shoes" by giving the brake pedal a hard push - And I do this with the booster working of course - so that means a petrol engine would need to be running.

And another thing worth mentioning - If the linings are worn (even though they may still comply with minimum thickness specifications), their arcs may be so mismatched to that of the drums that brake peformance will be impaired (with adjustment unable to rectify the situation).

 

[Pin_Head]

If the linings are worn (even though they may still comply with minimum thickness specifications), their arcs may be so mismatched to that of the drums that brake peformance will be impaired (with adjustment unable to rectify the situation).

Huh??

The drum and shoe wear together, so their arcs are matched quite well.

 

[mooker82]

Used search, but my specific question was not answered.
My brakes have been slowly getting worse and in need of adjustment. Took it to the local brake place, and they adjusted the little thing through the holes on the backside of all 4 wheels. Drove it away, and had no brakes at all.
Took it back in, and this time they pulled the tires and adjusted the little turn-wheels inside the drum. Put the tires back on, and the wheels would spin a bit, but with noticeable binding. Drove it away, and the brakes still did not work.
My question is: what is the correct adjustment for these drums. Do they need to be loose, barely touching, or binding, and how do you know when it is correct?

Have you or did they check the brake shoes? If they are dragging and your brakes still do not work there is something wrong. The brakes are easy to work on and replace but kind of a pain to adjust sometimes.

 

[amaurer]

Huh??

The drum and shoe wear together, so their arcs are matched quite well.

Unless, for example, the return springs are on the wrong sides (both on the same side) and its caused the shoes to wear at an angle (there are pictures of this happening in the "drum brake tech" thread).

 

[Pin_Head]

If you have an adjustment problem, you would be complaining that you have to pump the brakes to stop, not that the brakes are "weak".

 

[lostmarbles]

Huh??

The drum and shoe wear together, so their arcs are matched quite well.

Yeah - I think I worded what I said incorrectly Pin_head.

What I meant to say was - The leading edge wears much faster than the trailing edge of a shoe. So a shoe can become "difficult to adjust" by the lining at the "leading end" becoming significantly thinner than at the "trailing end". (Yet the lining thickness even at the thin end may still exceed "the minimum thickness specification".)

This uneven-wear can result in the shoe arc not matching the drum arc - but not necessarily so.

My original linings lasted something like 200,000km and were then still exceeding the "minimum thickness specification". But when I replaced them all, I found it so much easier to adjust the brakes and get the pedal high (with next-to-no-drag when rotating any wheel by hand).

 

[GregFrench]

Thanks, all. They were too tight. I backed them off and did the adjustment stated earlier. Now they work well again. No more avoiding red lights and stop signs!

 

[slickrock]

Since it is going to come up, Ocnce the brakes are adjusted until the wheel cannot turn and they are back off between 2 and 5 adjuster turns, how many times do people feela wheel shuould be able to spin before knowing if the brakes are too tight or too loose? I have read that that the wheel should rotate one full turn at least and somethat thy should only slightly drag but turn full rotations at least 4 or 5 times.

I know what works for me, but how about other people's stance on the number of tire revolutions for a properly adjuste brake drum?

 

[Pin_Head]

In the shop I worked in 35 years ago, we would spin them hard and if they went around once, we would call it good. Properly adjusted brakes drag a little. It is just the way it is. If you back it off so far that there is no drag, you will be double pumping.

 

[Pin_Head]

Thanks, all. They were too tight. I backed them off and did the adjustment stated earlier. Now they work well again. No more avoiding red lights and stop signs!

Your description of the problem is weak.

If they were too tight, you should have been complaining that they were smoking hot and stinking, not that they were "weak".