Good Ol' Drum Brakes (1 Viewer)

[nicksfj-40]

I recently replaced my rear wheel cylinders with CCOT's replacements. Put new shoues on and had my drums turned. Bled everything. Master cylinder, each cylinder. Got in expecting to have awesome barkes and it still takes two pumps to get good stopping power. So I jacked the back end up and adjusted the shoes so that they kinda rubbed. Jack the front up and adjusted them as much as I could. the front drums are kinda out of round. Re bled everything. Still takes two pumps but I can get the tires to lock up. Whats the deal? Am I missing a step? Do I need a new master cylinder? Once I get good braking pressure it doesn't fade like I think is a sign of a bad master cylinder.


P.S. I dont want rear disks. I dont even have front disks. So dont tell me to get disks. MAybe later. I need a raise.

 

[Poser]

Sometimes the shoes are not centered on the drum when you are adjusting them.


I have found that I set the initial adjustment, move the truck forward and backwards using the brakes to seat and center the shoe on the drum, and then adjust the shoes again.

It typically takes more than the initial adjustment to get them to function properly.

I have a 03/72 40 that still has drums all around with 33's....And if you dynamite the brakes and are not ready for it, your head will hit the steering wheel.



You said that you adjusted the fronts as much as you could….do you have any frozen adjusters up front? If the shoes are not properly adjusted at all four corners, you will get long pedal travel, or be required to pump the brakes in order to make them function, and have the truck pull one way or the other during braking since all four corners are not working together.

 

[crushr]

I wont tell you to get disks. But for your safety, and the safety of everyone on the road with you, you should.

 

[camcruiser13]

nothing wrong with drum.

more surface area than disks,
but when wet... trouble


get front dics when you can afford them. nough said

 

[stumpy]

i agree with poser. i used to have to adjust, reseat, adjust and then check about a week later to get them right. and when they are right, they work GREAT.

i would usually adjust the shoes so that they would just barely rub the drum when i turned the wheel. most people back them off from that, but i found that would usually give me great pedal height and did not seem to adversely effect the brake wear. i could usually get 50K+ miles out of the shoes without an issue.

and if you didnt lube up all the hardware, you might want to go back and do that. it makes the adjustments easier, and it will make it easier to deal with the setup the next time you have to tinker with the brakes.

 

[jcannon0]

1970 drum brakes

I have a 03/72 40 that still has drums all around with 33's....And if you dynamite the brakes and are not ready for it, your head will hit the steering wheel.

Can a 02/1970 drum brake setup be tuned to grab as tight. Sometimes, I have to pump three times plus, Once the pumping is done, they grab and hold, but I sure have to work them. In 02/1970 there is only one line coming out of the Master.

 

[MoCoNative]

I have a 4/73, still stock drums, brakes are pretty good on it. One thing I found was the rod that connects the brake pedal through the firewall to the brake booster can be adjusted. It has a lock nut on it, loosen and turn it with some pliers, or by hand if you can. It doesn't take much adjustment, and there are specs in the book on pedal free travel and height from the floor board. Get those correct and get the pedal to where you like it.

Whenever I dismount the booster or master or whatever I adjust this, it may get out of whack with time too.

I drive around town with a pair of pliers in the seat and test it out. If you have too much free travel the pedal will travel a long way before you get good braking affect. Hence two pumps may be nescessary to get good pressure. Then if the freetravel is too tight, you barely hit the pedal and it locks up. So I drive around a bit, try the brakes, make a little adjustment, try it again and so on.

Be sure and maintian some free travel though. For one it keeps the brake booster from being activated at all times, and two it allows you to ride the pedal a bit without actually setting the brakes, just like riding the clutch pedal a little.

 

[nicksfj-40]

yo

The only reason that I would put on disks is because of the maintanance. I will try and adjust them some more. Poser the reason I said that I adjusted the front as much as I could is because the drums need turned. I will do that tommorow. Thanks for all the replies.

 

[stumpy]

if your drums are out of spec, you may not be able to adjust the shoes enough to get a good pedal height. and if they are indeed out of round, you may not be able to get them adjusted enough to make them stop well. out of round will make a big difference in your adjustments.

 

[IDave]

I wont tell you to get disks. But for your safety, and the safety of everyone on the road with you, you should.

But remember, they put antilocks on disk brakes for a reason, and your conversion won't have that.

 

[nicksfj-40]

Well the out of round fronts may be my problem then. I will turn them tomorrow and re adjust. I will report back my results. Thanks.

 

[Coolerman]

A thread a LONG time back had a post from POSER that mentioned yet another issue with the drum brakes. There were a lot of OEM and aftermarket drums that were thin in the center face area and when torqued would actually warp the drum! No way to get a good adjustment due to the grab effect. CCOT and I'm sure others sell a thicker faced drum that cures this issue.

 

[Gundy]

Sometimes the cylinder is not adjusted out far enough and the
extra pump is needed to get full shoe contact.
I adjust each cylinder until the wheel can't be turned by hand.
Not just rubbing.
I then back off about 3 clicks. Do this for every cylinder. All 8.
It's worked for me. Results may vary.
Having even one cylinder not fully adjusted can result in the "Cruiser Pump".
Tip: Lather those adjusters with anti-seize on the threads.
They are notorious for getting stuck.

Tip #2 : Get the SST adjuster tool. It makes this much easier
and it's cheap.

 

[dbarrett]

Something to check that is often over looked is that the screw thingy on top of the cylinder is facing the correct direction. It has a wedge shape slot that the end of the shoe seats into. If it is not facing the correct direction your shoe will slide/move left to right and will take extra pumps to stop. The previous owner did a brake repair and did not adjust them correctly. Jim C noticed it while at my house and helped me correct it. Check the manual if you got one-there is a drawing some where in it. Like Poser i have a 3/72 40 with 32s. I have no problems braking with properly adjusted drums all around.

 

[Poser]

Can a 02/1970 drum brake setup be tuned to grab as tight. Sometimes, I have to pump three times plus, Once the pumping is done, they grab and hold, but I sure have to work them. In 02/1970 there is only one line coming out of the Master.

Yes.


When I originally purchased my Red truck in September of 1988, one of the first things I did was to go through the brakes completely using new OEM pieces from Toyota. New Master cylinder, all eight wheel cylinders, new hoses, many steel lines, new brake shoes all around as well as new drums. I had 31” tires on the truck at the time and the brakes worked great.




It sounds to me that you need to adjust your wheel cylinders to get the brake shoe closer to the drum, since the need to pump the brakes is usually a sign of the brakes needing adjustment.



If your adjuster wheels are frozen, remove the drum and try and free them up. If they are still rusted solid, you will likely need to replace them, and if that is the case, I would not even think about wasting the money on drum brakes, yes I said, wasting money on drum brakes.



After dropping all that cash on my drum brakes over the winter of 1988, the front axle was removed and replaced with a 1977 disc brake front axle assembly in the summer of 1992, along with installing a rear disc brake conversion at the same time.

 

[Poser]

But remember, they put antilocks on disk brakes for a reason, and your conversion won't have that.

And your drum brakes do not have it either David, moot point.....


The brakes in that 03/72 are far more touchy that any disc configuration I have ever operated, including many race cars.

 

[crushr]

Sure, drum brakes will stop your truck (assuming they are not too far out of adjustment), however, they (1) are much more prone to brake fade than disk brakes, (2) their wet-stopping ability is much more compromised than that of a disk brake system, and (3) the land cruiser drum brake system is not self- adjusting, which means that if you do not constantly adjust your brakes at all eight locations, your brakes will be out of adjustment and their performance compromised.

Disk v. drum brake performance is not an issue of surface area, nor was ABS developed for any issue inherent solely to disk brakes.

Disk brakes perform better, are more reliable, and will stop your truck faster in all conditions. There is a reason all modern car and light truck brakes are disk brakes, and have been for almost 25 years.

 

[IDave]

And your drum brakes do not have it either David, moot point.....


The brakes in that 03/72 are far more touchy that any disc configuration I have ever operated, including many race cars.

True, Steve. But I was addressing the safety issue which had been raised, not the other reasons to . I'm saying I believe that in many conditions, it is easier to lock up non-antilock disc brakes than it is to lock up drums. I guess your's was the exception. I will otherwise readily grant the advantages of disc brakes.

 

[Poser]

(3) the land cruiser drum brake system is not self- adjusting, which means that if you do not constantly adjust your brakes at all eight locations, your brakes will be out of adjustment and their performance compromised.

There is not a drum brake system on a Land Cruiser that is self-adjusting....


Even on the 08/80 and later 40’s, along with the 60 series and the Mini trucks, the only way to adjust the rear brakes is to use the parking brake, unless you get under the truck and do turn the adjusting screw manually with an adjusting tool.



The parking brake mechanism is tied into the rear brake shoes on these vehicles. Using the parking brake regularly on these models insures that the rear brakes remain adjusted properly, and that the parking brake pivot block and cam arm do not become seized because of dissimilar metal corrosion, and lack of use.




Operating the vehicle in reverse and applying the brakes does not adjust these drum brake systems.

 

[Poser]

I guess your's was the exception.

I do not think that it is the exception David, I know of a number of four-wheel drum brake Land Cruisers running tires from 28” to 33” that have brake systems that function very similar to the one in my 03/72-40 series. Also, I am very familiar with threshold braking a non-ABS system David.