• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

Need to do rear brakes but confused by rear end

Thanks Don, you know what they say about pic's. Just from "looking" the stock backing plate has only about an inch of offset. It also answers my Q about the wheel cylinder location, it mounts to an offset in the backing plate. Here is the pic of the two hubs side by side.
brawler_hub3.jpg
 
millsroger said:
Thanks Don, you know what they say about pic's. Just from "looking" the stock backing plate has only about an inch of offset. It also answers my Q about the wheel cylinder location, it mounts to an offset in the backing plate. Here is the pic of the two hubs side by side.
View attachment 34785
Click to expand...


Looks to me like they have the 2 hubs sitting opposite ways. The one on the left looks to be upside down from the one on the right.
 
THEFERMANATOR said:
Looks to me like they have the 2 hubs sitting opposite ways. The one on the left looks to be upside down from the one on the right.
Click to expand...

At first glance yes, but when you look at the raised shoulder the studs go through they have the same orientation. If the studs were in the one on the left it would be more obvious.
 
BTW Don, saw your sig, I have same year FJ. Whipple/AutoRotor SC with bypass and electric clutch, lift kit, 33x12's, unleaded valves, seats and guides at 200k along with full balance, aussie in rear, electric in front, disconnector links, air bags with leveler. Wife calls it the "rockababy". Out on the hiway it rocks on the tires--only rig she nods off to sleep in. Did Ruby and ran Pike's with it.

Correction, not electric---air. electric switch on dash---oops
 
millsroger said:
Thanks Don, you know what they say about pic's. Just from "looking" the stock backing plate has only about an inch of offset. It also answers my Q about the wheel cylinder location, it mounts to an offset in the backing plate. Here is the pic of the two hubs side by side.
View attachment 34785
Click to expand...

For the hub on the left, it looks to be different than the one I picked up. What is the drum to face end of the hub measurement?

So far my FJ40 is almost stock. My brother had it before me and switched the three on the tree to floor and put in a manual saginaw box.

The mods I've completed, or almost completed are four wheel discs (amazing what a difference this made), Scout power steering and GM steering column, installed FJ55 rear springs in front and rear. These springs are a few inches longer than stock which extends the wheelbase a bit. I'll probably move the rear axle back a bit more, but haven't made up my mind yet just how much. Just before I did the FJ55 springs I discovered the motor had a cracked head which wasn't repairable. I did find a "new" head but it needs about $350 of work to make it useable, so I'm saving that money and putting it towards a motor swap.

Planned mods are a 6.2 diesel motor, Ranger OD, 60 series four speed tranny, 203 doubler on a 76 year model transfer case, 3.73 gearing, and 60 series axle housings. I have slowly collected all the above parts, just needing a bellhousing, flywheel, clutch parts, and exhaust manifolds to be able to start the drivetrain swap. I do have these parts located now, just waiting for the guy I'm getting them from to finish a project so he will have the time to pull the parts I need.

I haven't been able to drive it for about three years now and I'm really looking forward to driving it again. Hoping that all the mods I've planned will allow it to drive/handle good on the highway and return good fuel mileage AND still have good offroad gearing and handling.

Don
 
Yep, I noticed that too, yours looks shorter overall, might be the burb version, dunno. I should be heading out tomorrow to pick up the parts. Will pay attention to the hubs he has. He is 200 miles away so I don't want to do any running back and forth. I might not change hubs, just put the drums on the outside of the originals, gonna do some measuring today.

Running gear on my FJ is original, sort of, mostly 55 now. Kept the 40 springs but with air. I like the SWB. Used a Unibody injector with a home made controller that tracks MAP, temps and TPS sensors. Running about 24 psi boost at max. Will burn all four off the line in second gear with the SC on. First time I did that in first gear it stripped the teeth so I put the electric clutch in and never dump the clutch with the SC below second HI.
 
Made the run yesterday to pick up parts. Match turned pair of near new drums, hubs and backing plates from a '96 3500. Guy runs Precision in Redding Ca. The hubs were the same as the ones Don posted pics of. I noticed a step on the hub where the drum sits for centering the drum itself. Today I will pull a wheel and one drum from my truck so I can compare.
 
I'm interested in knowing what you find when you pull the wheel/hub. I'm also curious to know how the backing plates compare to the ones I have here.

My hubs have that same step. Check out the ones you posted pics of earlier. The hub on the left sure looks like it also has a step for centering a drum. I can't tell for sure if the other one in the pic does, but I think so.

On my hub there is a second step which I'm thinking is for the rim to set on since these vehicles are set up hub centric for the rims.

Don
 
Still early here, gotta have my coffee. Am hoping that the existing hubs have enough meat to cut the step on the outside of the flange. That's what I will look for. Gonna just pull the wheel and slip the big drums on backwards to see how they fit over the lugs and against the flange. Worst case is to cut it enough to use a ring cut from some tubing.
 
I just looked at the pic of the two hubs, able to blow it up. Looks to me like there is a step on the outside of the flange, hopefully it just needs to be dressed up a bit.
 
OK Don, I took the backing plates apart and thought I had a problem. As it turns out I have what we would normally think of as two of the same side. The E brake cable comes out the same direction on both plates. Apparrently, the 3 1/2" wide 1 ton brakes use a different E brake cable that comes out to the rear on one side and loops back around. It is much longer than the E brake cable on the 3/4 ton, they come out facing forward so you have a left and right backing plate. My good news is that it came with an intact long E cable so I just have to figure out the clamps and which side faces front.
 
I just went back to look over my pics of the loaded backing plate (I'm being lazy and don't want to go outside in the dark). The plate I have has two bosses stamped into it so that just a matter of where it is drilled determines if it is a right or left side plate. Maybe one of your plates could be re-drilled, new internal e-brake parts used, and your current e-brake cables used.

At this point this is pure speculation, but are the 2 1/2" and 3 1/2 " internal parts the same, just the different shoe width?

Don
 
Old proportioning valves can stick in the limiting position and the rear brakes don't work very well. My 1st 1993 had this issue. My second 1993 was day and night better brakes. Adding the $100 shoes also improved the brakes.

Using new (or smaller diameter) drums on used shoes will make all kinds of noise. The shoes are worn in to the larger drum diameter. I had warped a rear drum and replaced them w/o new shoes. After sounding like a semi truck stopping for a month I replaced the shoes.

The auto-adjustors don't. You need to snug up the drums every other oil change. A screwdriver works for this. Block the front wheels, raise the rear wheels, and spin them while tightening the brake wheel. Stop when you hear the brakes start to drag. Apply the brakes a couple times to make sure you don't need more esp. on brakes that haven't been adjusted in a long time (miles).
 
Run your adjusters a little loose to seat in the new shoes.. It takes a while. These big shoes have a hair trigger for self-energizing, they tend to 'catch' when brand new. You don't want them costing you MPG or un-due grief.

I replaced ALL my hardware with new - EVERYTHING adjusters and all. They actually do what they're supposed to now. :)

I'm real curious how much rear hub wobble you have. (my vid)
 
Yep bosses are there, both are drilled for what we would normally call 'left'. Looking at the cable routing for my 3/4, RH cable comes from left side across the diff and arcs forward and in. Should be long enough to arc back and in, if not the cable that came with is a bit longer.

Haven't compared pieces parts but AZ has different part numbers for the kits. I suspect different spring oomph.

What this really means is that the E brake is working the rear shoe on the left and the front shoe on the right. Might be a good thing since one side binds forward and the other binds in reverse.

Been down the "wobble" route before--1-bad drum on a Ford, 2-bad Dodge wheel so tight on hub that lug nuts did not seat.

In this case, the 3/4 ton hub has a step where the drum will be--outside the flange--fit to drum center still unknown--will have the back end up on blocks today to find out. Right now tho the wheel goes over the step but is loose enough for the lug nuts to center the wheel---as it should do.

Once I have the hubs off and split from the drums, they and the wide drums go to the shop. Either the step gets cut to match or a spacer ring is added--either way- no "wobble".

Will be checking the auto adjusters. Thing to remember is that you gotta buy two left side kits.
 
Thought I might tell you guys why I am doing this. Not as simple as "bigger brakes are better" cause that's not always true.

Don't know about you guys but I have been on slippery roads with too much front brake. If you are in a turn of any kind the front end pushes to the outside. RH turn means right into oncoming traffic. Too much rear brake and the back end steps out. If I am gonna skid into oncoming traffic I would rather the back end get hit first. Weeeeelllll, that's the problem--too much front to start with plus ABS in the back making it worse.

My Mini has independant 4 wheel ABS. Only time it really works right is on hot dry asphault for straight ahead stopping distance. Any thing else and it twitches sideways. When I go to a rally I turn it off and use a manual bias control or I can't corner worth a damn.

My reading and research tells me that when the Disc/Drum set up went on the F/R brake bias went out of balance, when RWABS was added the brake bias went all to hell. That "proportioning" valve was a research addition because the rears went to ABS too fast with a light load. Valve backs off the pressure to the rears at a certain point. That only works at a certain load and on certain surfaces, wrong for everything else. The TB for the burbs is evidence of that--still not a 'fix'.

Only way to really fix it is to up size the rear brakes. That way there is more braking at the same brake pressure.

I drive up and down the mountains in the winter with ice, snow, slush, water, on curvy steep grades, with or without a load. My driveway is a 3 mile long 'slightly improved' dirt/gravel road similar to logging roads. I already added an ABS off switch to the Dodge Dakota and it automatically kills the ABS in 4WD. Will be doing the same for the Chevy.

What I am doing may not be good if you drive your truck as a flat land commuter. In my case, going down a grade with a fully loaded water tank in the back and full fuel says I want all the braking I can get.
 
Interesting reason for wanting bigger rear brakes. Around here we deal mostly with hydroplaning concerns. We seldom deal with the slippery stuff. I want better brakes, front and rear, for towing purposes. I don't tow heavy, but I much prefer brakes that feel like you don't have to stand on them when in a tight spot.

Problems with the proportioning valve, like warwagon brought up, is something I had never though of so I'm going to have to check that out. I'm not sure yet how to check it though. I'll find something on it.

Don
 
When hydroplaning brakes don't work anyway.

Saw a write up about brake testing, I think here somewhere. Pressure gauges on front and rear. Part of the 'fix' for the burb maybe?? Anyway, as I remember it, F and R track to about 600 psi then the valve kicks in and the rear holds there or climbs slower than the front. Changed to a different valve that kicks in at higher pressure but only for some models. I was not able to figure out if wide or narrow rears. Valve has two failure modes, blockage or sticking open. It is tough to get truck brakes to balance out because of the different loading. Light loads and the rears lock up, heavy loads and the rears don't help as much. ABS will help with the light load lockup but you need enough to have the rears work when loaded.

You might go find a dirt road with some turns and hit the brakes hard in one of those turns when empty, then with a good load just to see what happens. Go look at the skid marks. When light you will probably find almost no marks from the rears due to early ABS.

When this is done I am gonna do some testing, might need to swap to the hi pressure valve, time will tell. Should have enough time before snow.
 
Here is an update: Got the truck blocked up, one axle out and one drum assembly off. (Good thing too--shoes getting thin), step on existing hub smaller than hole diameter of wide drum--------BUT----

Wide drum on the hub that came with it, (used a couple of lug nuts to secure it), measured from the outside of the hub to the inside of the drum 9 1/8". Existing hub and drum assembly, measured the same way 9 1/4".

Also, the two hubs are exactly the same length.

So, the inside of the wide drum will be 1/8" out from where the existing one is. That means to that point it's a bolt on swap.

What is different is the set back of the backing plates. Will post the actual difference once I have this one off. Got the E brake off and out, gonna wait till I pick up new wheel cylinders to crack the hydraulics. Will also do a side by side look see re the E brake arm and the auto adjuster.

Guy on Pirate 4x4 said that there is what he called the A and B version, looks like one of the differences is the location of the backing plate boss on the housing.
 
You must log in or register to reply here.
Back
Top