74 drum brake system tech

[rsbcruiser]

One more procedure to do while down there.

OK, first, to get this going requires an exact adherance to proceedure! First of course you want to fill the Master cylinder up wiith brake fluid. Next, step into the cab and pump the brakes happily bleeding them through that one of the four (your choice here guys) brake hose connectors to the wheel cylinders. When you do this, make sure to leave that one fitting nice and loose! Next.......darn! guess I will need another picture.

 

[Coolerman]

So what's your theory as to why the brakes are set up this way?

 

[rsbcruiser]

Right there!

Now when you get up to go get the rubber gloves you will inevitably forget in your hurry then be sure to position your noggin to strike this corner good and hard! Come on! don't tell me you have'nt done it!

 

[rsbcruiser]

So what's your theory as to why the brakes are set up this way?

Gotccha Coolerman, told ya I'm a sly one! Jumpin the gun are you! Coming to a premature conclusion can get ya in trouble!

 

[rsbcruiser]

Because its' a LANDRUISER thing Coolerman

From a Mechanical Engineering standpoint I am intruqued Coolerman. I actually just got a grip on this while doing the rebuild shown here. When I put my Carhartts' on, hook a thumb in a pocket and scratch me noggin I LIKE it. I See it is like this. If the backs loose brake fluid then you are possibly hosed there. You might not be able to tighten them enough to turn them into a dead man drag, but those fronts! Crank em up a bit, jump in and overpower them down the hill a ways. Let em cool a while, NEVER poor your beer on them to cool, unless of couse it is miller. Jump back in and do it again. My thinking, It IS a Landcruiser thing Coolerman!

 

[rsbcruiser]

Brake adjustment frequency

I venture to guess I will be adjusting them a few times in the next few weeks. Long term.....it is a pedal travel thing. Depends on how much pedal travel you are willing to put up with. Of course you want to stay away from that firewall. I wonder though, maybe letting them go a while and tolerating some extra peddle travel will actually prolong the life of the system. Anybody?

 

[rsbcruiser]

Beginning Brake actuator system adjustment

I begin this section with the 96th picture! Thats alot! Any survivors? To make a point. Concerning the brake peddle heigth adjustment, I had to dig the correct numbers and instructions out of both of these books. The description in my FSM was not possible! Maybe it was because the book is a 74 and my FJ55 is a 10/74 I don't know. The Haynes on the other hand had the right diagram but, the correct number to use turned out to be for a non servo (brake booster to us here in the good ol) unit.

 

[rsbcruiser]

Where to start?

A tough question. Lets start assuming you have all of the brake actuator system in working order and you want to know if it is your adjustments in the system that are messed up. Just pull that pin.You dont have to really, but doing so will tell you alot. The alingment of the holes after the pin is out will tell you if the problem is forward of the pedal. Of course, it might just be easier to yard that return spring that attaches on the other side of the pin and grab hold of the pedal to see if there is a little free play. IDK.

 

[rsbcruiser]

The real Stuff!

See! I have been thinking about this part for a while. Now that we have gotten rid of those too afraid to remove their Master Cylinders we can begin! Take it off! dang it. As shown in a FJ55 first remove your defrost hose and disconnect the stop light switch wire.

 

[rsbcruiser]

Now, remove the return spring and loosen the locking nut behind the stop light switch. But! don't do that until you look at the next frame and find lo and behold it might just be a good thing to yard that Master Cylinder. Once the stop light switch lock nut is loose, back the stop light switch all of the way out. Take it off if you want to but that is not neccesary.

 

[rsbcruiser]

Philipino rattan!

Makes a great third foot. Use something to keep the peddle depressed while you are trying to get access to that pesky stoplight switch lock nut. You have to have the Master Cylinder off for this to happen. Almost worth it all by itself!

 

[rsbcruiser]

The theory

First, lets consider the next step. The procedure here is to set the pedal heigth, of course. The picture illistrates most succinctly what the peddle heigth is. Now lets step back from this whole thing and consider what we are really doing. There are three variables here, lets give them names. The stop light switch adjustment, the booster pushrod adjustment and the Master Cylinder pushrod adjustment. All three can be either adjusted in or out. So, that is for the M.E. mind, fairly simple. 2 X 2 X 2 and of course the answer is.......8. Eight ways to screw this thing up, think about it like that and you are on your way to fixing this little mess. First, we have eliminated one variable, the stop light switch adjustment. The Master Cylinder is off so now we have eliminated the other variable, the Master Cylinder pushrod adjustment. So now all we have left is the brake booster pushrod adjustment. Thats' next. But first....The numbers. All of the numbers you see in your books were at one time taken from fractional inches, converted to metric and then converted back to decimal inches. O YES fellows that is right. You probably heard it here first. All those stupid numbers are is a failure to think clearly by the guys writing these books. That is ALL. So, what does that mean to you? Simple, let me show you. For the peddle heigth the book gives a funky number, it is 6.77. What the hell is that? It is simply 6 and 3/4 inches. The peddle free play, given as 0.12 to 0.23 is really 1/8 to 1/4 of an inch, silly really if you think about it. Ok then, there you have it. I am trying to make a greater point here with all of this Southern Engineer vrs Mechanical Engineer stuff. The point WILL culminate with a WINNER clearly on top. Venture to guess who will be winning this argument?

 

[rsbcruiser]

Adjusting the brake booster push rod

Mental check list..the return spring is off, the stop light switch is backed off and the Master Cylinder is off and the Master Cylinder pushrod is removed. Now to adjust the brake booster pushrod. first loosen the Brake booster pushrod lock nut. See the pin, yep it is in place for this next step, of course, you didn't really pull that thing did you? With the lock nut loose use adjustable pliers to adjust the rod length to the correct peddle heigth. The heigth is not the only variable. There also must be some free play too. So the two numbers are actually additive if you think about it. So adjust for peddle heigth plus free play. Tighten the nut back up and put it all back together. The last important step is to adjust the stop light switch. The only important thing about that adjustment is to make sure you don't turn it into a peddle stop, therefore driving the pedal into the booster. That free play must be maintained. All done here, time to move on to the other side of the firewall.

 

[cruiser88]

Well done man. Should be a great help to newbs and old folks alike.

 

[rsbcruiser]

Well done man. Should be a great help to newbs and old folks alike.

Thank you crazy88!

 

[n2666s]

wow............Rich, keep on dude, my 4 corner drums are giving me fits..........well bled, crisp adjusted BUT they are not "grabbing" like I expect them to.......feel good and crsip BUT no stopping power..BTW what is "jeller bean"?


Lou

 

[rsbcruiser]

Joe Meeks

wow............Rich, keep on dude, my 4 corner drums are giving me fits..........well bled, crisp adjusted BUT they are not "grabbing" like I expect them to.......feel good and crsip BUT no stopping power..BTW what is "jeller bean"?


Lou

, Why Lou, I am glad you asked. feller bean = fellow being of course and was a term seen in several Pioneer diaries when quoting Joe Meeks. Now Joe had a much better known brother, Steve Meeks. Steve trapped throughout Oregon with the Ogden party. One of Oregons' first trapping parties. Steve and the guys traveled throughout Oregon, meeting the locals and generally having a "good time". Well not exactly, it was tough for them but they got along, even recieving some help from the Shoshone. Joe, on the other hand, was a true blue Scallywag. Leading a Pioneer party through central Oregon. Promptly getting them lost and in the process angering the Shoshone something fierce. NOT a good idea! It hardly needs to be said but of course most of the party died. An in depth look at Joe, who managed to continue these practices into his 80s', reveals that this one incidence was in fact a high water mark. So, anyone care to guess which brother I admire the most?

 

[rsbcruiser]

Oh no, another tangent!

Um, like I said earlier, it might be a good idea to mind your torquing when tightening any of the brake line nuts. Here I am, filing off a little from the nut to remove the swell put in it by....Who Me? Like I said, an amateur mechanic.

 

[rsbcruiser]

The devil in the detail

There he is, the root of many a Landcruiser mechanics downfall. Yep, thats him folks, that pesky little Master Cylinder pushrod. Just calling him out for you. Now lets deal with it. Look at that! I am using the flats on my calipers when everone will tell you to use only the tips. Another paradigm! I like paradigms! Give me a break on this one guys. Many times in your life you will or have run into two of the paradigms predominant in the Industry. One I will call Old guy knowledge. The other is the text book said so knowledge. between the two somewhere lies the truth, seek it out!

 

[rsbcruiser]

A completely useless picture.

Hey! what do you mean, putting down my pretty picture like that! Well, almost useless. That is a quarter turn. 90 degrees. Hey don't laugh, once I screwed this up when torquing head bolts on an aluminum motor. O no! I think I just outed myself! Ok, I am not exactly a pro but I do have some experience in wrenching. It is my Landcruiser that has set me back into the realm of true amateur mechanic. So two birds in one. Most of the intervals shown on the second of the two pictures after this one are a quarter turn. Hmmmm, non of you pros have ever used a caliper on one of these, I can tell! And I find that interesting. The other birdy, so think you know your stuff and tackling a Landcruiser should be easy even though you have never dealt with this type of technology. "where angels fear to tread". Newbie, you are warned!