74 drum brake system tech

[rsbcruiser]

Originally Posted by lostmarbles

Great write-up Richard.

I like my drums-all-round and I'm keeping them

Thanks Lostmarbles! You were one of the first people on this website to make personal contact with me. Remembering one conversation we had in particular, I definiteley listened to your advice concerning the subject matter and altered my conduct to reflect that advice. My respect for you and your opinions I hope is readily apparent.

[rsbcruiser]

I know, seems a tedious subject but I definetely have an opinion concerning this matter. Skip to the next thread if you do not want to read the wheel rantings of a ABET cert school Mechanical Engineer. I whip it out here because I have heard so many times about wheel mounting failures. Many of the root causes for these failures I am certain can be attributed to poor wheel mounting procedures. First, apply ample anti sieze to the threads of the wheel studs. Rust is not and never will be a correct holding method. Good thread conditions insure a proper torque is actually achieved. At this time the wheel should be completely clear of any weight or obstruction. The lug nuts are first installed by hand several rotations. This allows you to be sure you have not cross threaded and gives the feel needed to ascertain the health of the threads. Next, using the old school tool shown, I spin on the lug nuts to just touching the wheel. The second lug nut to tighten should be opposite the first. proceed this way until all lug nuts are just touching. Use the opposite approach until the last tightening step. Next, tighten the lug nuts until torque causes the wheel to rotate. Now, place the wedge shown under the wheel just enough to stop rotation. Tighten again until wheel rotation occurs again. Use your 3lb drilling hammer to drive the wedge in. now tighten again untill the ol school can tighten no more. Drive the wedge. Use a ratchet to achieve a higher torque. Note, with my 10", 1/2" drive and with my age and infirmities I am still able to tighten lug nuts passed their FSM torque. This is a good way to get some idea of the feel for torquing. Finally, drive that wedge out and set the wheel on the ground. Finish torquing the lugs to spec using a GOOD torque wrench. Now, for your last go around and at the same torque tighten sequential around the circle of lug nuts. Do this last step to insure you have not skipped a lug nut which is much more likely to happen using the opposite approach. WoW, lots of verbage! In practice it goes much quicker. made it this far? Great!, thanks for surviving my rant.

[rsbcruiser]

For all those who have lost their lives in defense of freedom. All flags.........furled untill the morning light of Independance Day. Except this one. It will always remain, half mast.

[rsbcruiser]

For all those who have lost their innocence to the horrors of War. Hope, for a better tommorrow.

[rsbcruiser]

Lets' adjust our front drum brakes. A little mule beating first, I apologize but a good understanding of the fundementals is helpfull to this adjustment procedure.

I have included this reference to a thread by Greg French with his permision. Another example of the resources available on Ihmud.

drum brake adjustment

[rsbcruiser]

Ok, as per earlier discusions. Left is right, right is left. The right hand thread brake adjusters go on the left side of the axle. And vice a verse for the right wheel. The left hand thread adjusters go on the right side of the axle. Think about this as you sit in the drivers seat. Your left hand is on the left side of your rig. That is the convention.

[rsbcruiser]

The proper way to orient your mind to understand this situation would be to think about this front left wheel front wheel cylinder lying on the ground looking up at this adjuster. Think of it as a right hand thread nut and bolt. Think of the adjuster star as the nut. To loosen the nut and therefore to tighten your drum you need to turn the adjuster as shown in the picture.

[rsbcruiser]

Lets move to the front left brake rear wheel cylinder. Your perspective for this cylinder should be standing over this cylinder looking down. The proper way to tighten this side would be opposite as shown in the last picture.

[rsbcruiser]

So, you recently purchased or have run your rig for a while since the last time you adjusted your brakes. As you adjust, pay attention to the amount of resistance to rotation. You will be adjusting the nut tighter. doing so will increase the amount of resistance to rotation. That means it will be alot harder to turn the adjuster when the drums draw up tighter. The beginnings of a disaster! The adjusters will be stuck but good! Drums stuck hard. So if you notice quite a bit of resistance to rotation it is definetly a good time to stop, pull the drum and perform maintenance as suggested by earlier entries.

[rsbcruiser]

right side adjusters are left hand thread. Go from there.

[rsbcruiser]

Adjustment should follow a straight forward proceedure. Starting with the pry bar close to the axle (as shown in the photo) engage the adjuster star. Pivot the tool away from the axle in the direction indicated by the arrow (there is a good illistration of this in the FSM). Listen and feel for the clicks made by the tensioner. Count the clicks as you go. Starting as shown, adjust a set number of clicks. Move to the front. Repeat the procedure. There should be no confusion on your part here. The procedure is not reversed, the adjustment is reversed. This is hard to verbalize but very important. The desire IS to adjust in the same direction as before. The correct way to think of this is to adjust both sides in the same convention. Away from the axle on both sides. Not away from the axle on one side then towards the axle one the other side. Remember, one of the earlier entries concerning this subject. Away from the axle to move the brake shoe toward the drum. Once you get this corny little concept down, you will never have trouble with brake adjustment. AMHIK! The adjustment tool is in the position shown in order to demonstrate the adjustment convention only. Experiment with your adjuster tool to get the best tool function to fit your taste.

[rsbcruiser]

Alright, you have adjusted both sides evenly. Now your shoes are close to making contact with the drums. At this point I start rotating the wheel back and forth with my left hand as I continue adjusting the brakes. This way I can hear and feel as the brake shoe comes in contact with the drum. As soon as I notice contact, I move to the opposite side of the wheel. Adjust until contact is made on that side. If you pay attention you can hear the difference between shoe contact on each side of the drum. Now, both sides are evened up. Adjust each side a couple clicks at a time untill the wheel can not be moved. few clicks more per side and the wheel should be locked solid. If you have a charged system at this point you could get in the cab and step on the brakes to insure you have proper shoe alignment in the drum. Now back off of the adjusters two or three clicks on each side. Done! Take it for a short test drive. Touch all drums (carefull, they might be hot) to cofirm the function of your drums. Even heat means even braking. Repeat the heat test several times. If you still have to double pump your brakes then the problem might be with your master cylinder setup. I am assuming here you have performed a complete service of all drums. There is an extensive road test description in this thread, entry 77.

Special thanks to Pin_Head for his timely contibution

[rsbcruiser]

The Mule is now in the barn!

[rsbcruiser]

I have highlighted this picture to demonstrate what I think is evidence of incorrect adjustment. Brake shoes are supposed to wear at the leading edges faster than the trailing edges. The picture shows that this is not the case here. The leading edge looks as though it has seen no to little contact.I am thinking that I overtightened these at one time or the other. One other possibility is that the Wheel cylinders have not been extending to their full reach for a while.

[rsbcruiser]

So assuming your brake job is complete, lets put it on the road. First of course is to jump in the cab and press the brakes. Give it a little muscle and hold for a couple seconds. Does the peddle drop slowly? Not good. Next, pump the brakes, can the peddle be pumped up? Not good. Notice your peddle height before proceeding to the next step. Now fire it up, run through all the above steps to see if there is a change. Pay attention to the brake light switch, does it click on and off when you step on the brakes? So, all is well and you are ready to road test. Good time to find out how well that emergency brake is working. Test it first, before hitting the road, your neighbors car, your mail box, your wifes car.....First thing you want to do even before leaving your driveway is to get a little speed up and then hit the brakes. Get out in front of your house and run it forward and reverse a few times. Get a little speed up and hit the brakes. Park the rig, get out and touch the drums, feeling for even heat. They should be just warm, pretty much even in temp.. Repeat this last step a few times increasing speed each time. Keeping speeds neighborhood fast throughout this phase. If they pull one way or the other then back to the garage. If drum temps become uneven then back to the garage with you. If one brake is hotter than the others then adjust that brake by backing off one click on both adjusters. Repeat tests. Still a good idea to hang in your neighborhood. If your brakes begin to bind up then it is most likely that the master cylinder is not adjusted correctly. Remember, there are no automatic adjusters on these things. A good argument for staying close to home at first. Alright then, that was fun! Now, yard your drums again. Have a look, is there any brake fluid leaaking from the wheel cylinders? No? then put the drums back on. When I checked my drums I only needed to back off one click to remove the drums. The result from my road test no surprise, the back drums were completeley cold. not good! Peddle returns to full stop most of the time, still returns slower than normal. Most likely the rear wheel cylinders are responsible for the dragging peddle.

[Fuzzy Logic]

in the end, a simple situation made difficult

[rsbcruiser]

Originally Posted by Fuzzy Logic

in the end, a simple situation made difficult

Timely and appropriate Fuzzy Logic. Thanks! Your opinions are welcome in this thread. I have dealt with brake issues on my rig now for the better part of 10 years. Replacing only the worn parts needed to get it back on the road. Never spending the time or effort to fully comprehend the situation. I am certain that my motivation for writing this thread can be directly linked to the frustration I have caused myself with this attitude. I am slso certain a good profesional would do a complete brake system rebuild on my Cruiser in several hours at most. My plan is to get ahold of a good mechanic I know, explain the situatuan and ask him how many hours it would take hiim to complete this task. My philosophy is that I should be willing to trade time for the expertise of a profesional. I would like to thank Slickrock for giving me his permision to include his thread in this one. I was wondering exactly where to put it. Like I said Fuzzy, timeley and appropriate.....

Brakes Still Randomly Build Pressure

Slickrock has shown determination and fortitude in his efforts to repair his brake system.

[rsbcruiser]

Even routine mainatence on your Landcruiser brake system requires planning. I live in a city with 2 million inhabitants and an active Landcruiser following. Even here it is difficult to find a source for off the shelf brake parts.

From Napa:
Parts are for a 10/74 FJ55 with the OEM brake system.

• Order quantity**part#****description*******price US$
• *****1********37586***wheel*cyl-left*rear***46.88
• *****1********37579***wheel*cyl-rt***rear***46.88
• *****1********37578***wheel*cyl-left**rear***46.88
• *****1********37578***wheel*cyl-rt***rear***46.88
• *****2********TS-469**brake*shoes*axle*set*26.99
• *****2********2450****hardware*kit********17.99
  

It will take 7 days for the above order to arrive.
Parts list above will get me everything I need to rebuild the rear axle drums except for the drums. List includes brake shoes for all four wheels.

[rsbcruiser]

Alright, now my brake system is wet and road tested. I am very suspicious of the hackney front wheel cylinder repair I performed so it is time too yank the front drums and have a look to ascertain wether the wheel cylinders are leaking or not. Pictures show left front wheel cylinders. I pulled the rubber boots out a little from their seats to see if they are resevoiring fluid. Nope, looks like this side is holding tight. Dry to the bone.

[Pighead]

An insightful and well-documented thread, rsbcruiser, well done. Should probably be a sticky.
I've rebuilt and replaced the rear wheel cylinders several times in the last 21 years...I appreciate how difficult it is to describe in the written word the simple procedures you describe. But we often have extreme newbs that need this exact procedure carried out in exactly this manner and we do tire of repeating ourselves.
But, aren't 55 rear wheel cylinders different from 40 rear wheel cylinders? Slightly bigger bore maybe?

[rsbcruiser]

Originally Posted by Pighead

An insightful and well-documented thread, rsbcruiser, well done. Should probably be a sticky.
I've rebuilt and replaced the rear wheel cylinders several times in the last 21 years...I appreciate how difficult it is to describe in the written word the simple procedures you describe. But we often have extreme newbs that need this exact procedure carried out in exactly this manner and we do tire of repeating ourselves.
But, aren't 55 rear wheel cylinders different from 40 rear wheel cylinders? Slightly bigger bore maybe?

Thanks Pig! Coming from a Rubicon running Iron Pig Owner I take that as a real compliment! I just ordered the rear wheel cylinders from NAPA so I suspect I was only able to do so because they are also on the FJ40. When I touch on rear brakes I will be sure to include a picture of the wheel cylinders. In this thread I make no mention of what type of rig I am working on. Maybe I should. If there are any differences between the FJ55 and the FJ40 I would be happy to include those facts. You are welcome on my thread anytime Pighead.

[rsbcruiser]

Looks like both sides are dry!

[rsbcruiser]

The Factory Service Manual has an excellent brake bleeding description, also try the 40-45-55 tech. section, search thread or search title, brake bleeding. I bleed using a vacuum bleeder. Most of you I assume don't have that option. I stuff something under the master cylinder to make sure brake fluid doesn't hit the paint. Of course, it doesn't hurt to have a good coating of POR15 under the enamel.

[rsbcruiser]

First step is to remove any old brake fluid from the resevoirs. Why drag it all through your system? If you are bleeding without the help of a brake bleeder then you will have to bench bleed the master cylinder first. Myself, with the vacuum bleeder, I blow off that step, a useless waste of time. Period!

[rsbcruiser]

I offer this picture to highlight a Landcruiser feature. While laying under my Cruiser bleeding my brakes I can see the master cylinder. Cardinal sin to let your master cylinder go dry while you are bleeding your brakes. You have set yourself up for a difficult situation. It is actually more difficult now than starting from dry because pouring more brake fluid on top of a system partially evacuated will trap air betwen the old fluid and the new.

[rsbcruiser]

Spongy peddle? Are you sure it is air in your system? How do you tell for sure? Don't because you will not believe how easy it really is. Sitting in your Cruiser with the hood up step on your brakes. Pay close attention to the fluid levels in the master cylinder as you do so. Now release the brakes. If you have air in your system, the resevoir level or levels will drop. release the peddle and the level or levels will rise again. If there is only a small amount of air in the system then the drop will be small but you will be able to see it. If the system is air free you will see brake fluid flowing back into the resevoirs when you release the peddle but no change in fluid level.

[rsbcruiser]

When bleeding your brakes there is a sequence that needs to be followed.It is really not that big of a deal since the brake system is set up with the rear brakes seperated from the fronts. Bleed all of the far side bleeders first. The rear brakes have only one bleeder per wheel. The fronts have two per wheel. All bleeders must be bled, no skipping. Between bleeds I always return to the cab and pump the brakes a few times. After bleeding the system to the point that there is no air I will bleed the system one more time. With the fronts you only have to bleed one side per wheel for any extended period. The other side should fill up with fluid, at least partially when you bleed the first one on that wheel. No need to worry about sequence when bleeding a front wheel. Front or back it does not matter.