HDJ81 Rear Disc Brake Upgrade (1 Viewer)

[Malahki]

I didn't order any backing plates, I was later told that my current ones could be dremeled to fit in a pinch.

I know you can cut the backing plates to fit on the front brake upgrade but I dont think it will work on the rears. Sure you can cut the outer lip off but the round center park brake portion is 1/2" bigger on the newer ones. So even if it works you would have to eliminate all the internals

 

[danakittilsen]

I am just in the process of assembling mine today. I ordered everything OEM and aftermarket for a 1995 FZJ80. Turns out the backing plates are still available some places in NA for $160CAD The overseas sources I checked were all over $400USD.
You will need to change your park brake shoes to the larger ones as well. Chances are all of your park brake internals are going to be rusted and siezed. You'll need the bellcrank, bracket, rubber boot and spring at very least. I ordered all the OEM pins and clips to but Im sure you could find substitutes. Most of them also came in the Raybestos spring kit I ordered.
Here are some pics and part numbers

The shop I was at couldn't find any of the Calipers or Rotors mostly looking through napa. I found the rotors and calipers that would be an upgrade from napa in one phone call. They did find the pads that fit my current calipers, and that got me back on the road.
I guess I'm going to need larger pads for the new calipers, and new backing plates and new parking brake internals (which I do need anyway, as my parking brake does very little over the last year).
@Malahki where did you order all your parts from?

@Rock40 Those brakes look amazing. So much want. for my fronts which will be next. Your truck's original brakes where already larger and better performance than the puny brakes that came on the early models. And then you upgraded beyond that. Maybe I'll just skip straight to the same rotors. I do have to grab/modify my front backing plates, but also upsize the calipers and rotors.

 

[Douglas S]

I guess I'm going to need larger pads for the new calipers, and new backing plates and new parking brake internals (which I do need anyway, as my parking brake does very little over the last year).

Literally everything in the rear braking system is the same except the rotors and backing plates. Check toyodiy.

 

[mudgudgeon]

You can also use 100 series pads in post 94 calipers, they have about 30% more friction material surface area so you get an increase in performance. The steel tabs on 100 series pads might need a little grinding to fit into the calipers though

 

[Malahki]

Literally everything in the rear braking system is the same except the rotors and backing plates. Check toyodiy.

And the park brake shoes

 

[danakittilsen]

Literally everything in the rear braking system is the same except the rotors and backing plates. Check toyodiy.

And the park brake shoes

Okay, so calipers and pads remain the same, rotors, backing plates and park brake shoes increased in size in late model? But these two year-groups of parts will play together?

 

[Malahki]

@Malahki where did you order all your parts from?

Backing plates were from 4wheelauto in Edmonton. Also available here:
#4650360081: PLATE SUB-ASSEMBLY, PARKING BRAKE, RIGHT. PLATE,BRAKE

Rotors, pads and spring kit are all local parts stores: Silver Automotive & Autovalue

Oem parts all from
PartSouq Auto Parts Around the World

 

[Malahki]

Okay, so calipers and pads remain the same, rotors, backing plates and park brake shoes increased in size in late model? But these two year-groups of parts will play together?

Yes.... Their are some other diferences in the actual part and part numbers (like the calipers and parkbrake bellcrank) but its all interchangeable on mine

 

[danakittilsen]

Backing plates were from 4wheelauto in Edmonton. Also available here:
#4650360081: PLATE SUB-ASSEMBLY, PARKING BRAKE, RIGHT. PLATE,BRAKe

Well s***. I am not interested in getting on the phone with 4 wheel auto. I have been burned by them, and then ignored.

 

[Rock40]

Hey Dana, on the front you don't HAVE to run the OEM backing plates (dust shields) if you don't want to. I eliminated mine and used these spacers from Marlin so everything fits back together correctly: Backing Plate Eliminator | Marlin Crawler, Inc. I've never been a fan of dust shields. I also elected to not run the 100 pads up front. From the reading I did, the 100 series pads are likely to last longer but actually provide no additional braking performance. That, and they barely fit/might need to be slightly modified. With that in mind, I just used the 80 series stuff.

 

[danakittilsen]

Got it all on and spinning. Or rather not spinning, when I press the pedal! What a difference. Nice feeling with all the extra weight this rig has gained in the past years.

And having a working park brake again is possibly the best part. Notice this the most, because in trying to test my brakes, I also noticed how little I actually use my foot brake with the manual transmission.

 

[veiloctane]

I think my ebrake cable is stretched.
do you guys think that the cable is also interchangeable?

 

[69 FJ40]

Will the backing plates:

48503-60081
46504-60041

Work on a HZJ 77?

Thanks

 

[Madcrix12]

so for the record, if you have a 1991 hdj81 with rear discs. you simply buy a rotor , hand brake shoes and backing plate from a 1995 US 80 series and bolt up? assuming all other exsiting parts are in good shape?

 

[Outono]

so for the record, if you have a 1991 hdj81 with rear discs. you simply buy a rotor , hand brake shoes and backing plate from a 1995 US 80 series and bolt up? assuming all other exsiting parts are in good shape?

As you said, you need the larger rear rotors, hand brake shoes, and backing plates.

80 series from 93 / 94 had OPTIONAL discs in the rear so if you're looking at sourcing backing plates from those years, make sure you're not pulling from a truck with just drums in the back. 95 and on had rear disc on all versions.

The thing not mentioned in this thread is that in order to pull off the old backing plates, you also need to remove your hubs. So unless you're willing to take a risk trying to put your rear axle back together with old parts, you should also source a rear axle rebuild kit.

 

[Madcrix12]

Tks. Will do just that. I am totally rebuilding my 80 with oem parts from ground up. Its almost 30nyears old and mint. Want to make it last another 30 years if possible

 

[oszkari]

Hi, I'm in the process of changing the rear backing plates on my 1991 HDJ81. I have ordered 46504-60050 (LH) and 46503-60050 (RH). Funny enough the RH side came with the oil seal + mounting bolts whereas the LH is missing it. Both are OEM. Can anybody help me out with the part number for the oil seal (red arrow on pic). I have been looking at 3 different places and I still cannot find it.

 

[Outono]

Here you go: 90313-93001

 

[oszkari]

Here you go: 90313-93001

Thanks!

Now you have got me thinking...the RH backing plate has that rounded lip in the middle (similar to the pic Malahki has posted above) and I thought that is serving as the seal/seal cover. I don't think 90313-93001 can fit in there, and I certainly didn't have it before. That makes me think that there are two styles of backing plates for 80 series:
1. one with that rounded centre piece which doesn't require the 90313-93001 seal , my RH backing plate
2. without the rounded circle which will require the seal, my LH backing plate.

Can anyone confirm ?

 

[oszkari]

I did a bit more reading, and if I understand it right option 1 is used with disc brakes and option 2 is used with drum brakes.

The hub side seals will differ too. Disc brake version will use seal 90311-62002 on the hub side and there is no backing plate seal.
Drum brake version will use the 90313-93001 and 90311-62001 combo.

Based on this my RH backing plate is for disc brakes and LH is for drum brakes


I looked again at the LH backing plate and it cannot be for drum brakes cause it has the mounting points for the brake calipers.. I guess I'm lost now..