Full HZJ80 brake system rebuild - booster to rotor (2 Viewers)

[mmajsw]

Excellent write-up.

 

[fjbj40]

Great job!

 

[DivByZero]

One week follow-up - No leaks, no issues. Car brakes better than it has in the entire time I've owned it. There are two things to report though. First of all, I made a mistake with the front brake line orientation. There's a notch on the brake line and the mounting bracket, so you can orient the lines in two different directions. I messed up and mounted both front brake lines upside down. This leaves the line rubbing on the swivel hub, and at worst, getting pinched in the front suspension:

I knew this at the time actually, but I just wanted to finish up and get the car back together. Fixed it today. If you find yourself in the same situation, there's no need to mess with those single-use copper washers and bolts, leave those undisturbed. Just unscrew the hard line, remove the clip, and flip around the hose at the mounting bracket. It'll now look like this:

Much better. At this point, just bleed the air out of the line using the caliper bleeder valve, and top up the brake fluid.

There's one other thing to report too. So one of the "candidate" channel seal replacements arrived in the mail this week:

These are not Toyota parts, they're actually for a variety of British vehicles, mostly from MG and Moss, part number 583-820. From searching for caliper seals with similar dimensions, I flagged these ones as potential replacements. The caliper manufacturers for these cars, Brembo and Girling IIRC, share a lot in common with the Sumitomo brakes, because they're all based on a Bosch design apparently. These channel seals are great, nice and smooth, good quality:

Here's what this seal measured in my calipers:
OD: 0.492in
ID: 0.290in
Thickness: 0.080in

The OD and thickness are basically identical, certainly within tolerance. The ID is a little smaller, but that's not actually a bad thing. It's the OD and thickness that are the most critical measurements. You can see back from the pictures I took that there's a lot of tolerance on the ID of the seal, the actual passage between the calipers is relatively small in the middle of the channel seal. This means the thicker ID of this seal, if anything, just makes a more robust seal than the one that was in there before.

If I was assembling my front calipers today and I had these channel seals, I'd use them without hesitation. Because this is a "standard", numbered part, it's easy to get too. If anyone wants to rebuild the 80 series front calipers, I'd recommend you order some channel seals with part number 583-820, four will do a pair. You'll find these seals easily available for a couple of bucks each from MG and Moss.

 

[Mojo Jojo]

This is a great thread; something I plan on doing sometime this year.

I may have missed it, but wondering if you have a parts list you can post with everything needed for the rebuild, including OEM and non-OEM parts, tools unique to this project, fluids, etc. I think most, if not all, that info is sprinkled throughout the thread, but it would be handy to have it all in one post.

And how much did you spend all together including parts, tools and fluids?

Thanks in advance.

 

[DivByZero]

I'll make some time to work up a list. I spaced out the parts orders intermixed with other stuff over the year or so prior to doing the job, so I'll have to go back through the orders and separate and tally it all. The cost is concentrated in a few main key parts though.

 

[CharlieS]

Excellent thread! I recently bought a lot of stuff, here are part numbers for some of it, in case it helps:

• copper brake washers (8) front and rear
  • 90430-10074
• brake line banjo bolts (4) front and rear
  • 90401-10015
• Toyota rubber grease 08887-01206
• 1x 04479-60020 Cylinder Kit, Disc Brake, Front (rebuild kit) - note this does both front calipers and includes the copper washers/seals for the banjo bolts
• 2x 47547-20030 Front Brake bleeder screws
• 2x 47547-12030 Rear Brake bleeder screws

Info:

04479-60020 front caliper overhaul kit. Does both sides. (in list above)​

04479-60030 rear caliper overhaul kit. Does both sides. (not in list above)​

Kits DO NOT include banjo bolts, bleeder screws, or pad retaining hardware.​

The three correct, extended brake line Toyota PNs that CDan researched eons ago (like almost 20 years ago):

• 90947-A2016
• 96940-34605
• 96940-34705

Rear brake soft lines at the caliper:

• 90947-02615
• 90947-02614

Note they are side specific.​

Front brake soft lines at the caliper:

• 2x 90947-02A16

Note: same on both sides.​

​

Seals between caliper halves from Moss Motors (not sure on the quantity, so I ordered eight):

SEAL, between caliper halves SKU: 583-820

8

 

[duece71]

Excellent write up OP! The LSPV on mine has the boot torn and I have a new LSPV plus the boot kit ready to go. Question…would it be possible to just make a mark or 2 with a paint pen on the LSPV and the metal “spring sensing” piece between the LSPV and the rear axle to avoid having to measure pressure? Wondering if it’s possible to simplify this proceedure.

 

[DivByZero]

Excellent write up OP! The LSPV on mine has the boot torn and I have a new LSPV plus the boot kit ready to go. Question…would it be possible to just make a mark or 2 with a paint pen on the LSPV and the metal “spring sensing” piece between the LSPV and the rear axle to avoid having to measure pressure? Wondering if it’s possible to simplify this proceedure.

If you don't intend to measure the LSPV pressures, your best bet is as you said try and mark the current position and match it. That did work reasonably well for my swap over. Obviously this assumes your current settings are right though, which may not be the case if you've done a big lift.

Honestly I suspect most people's 80s have LSPV settings that are significantly off. It can have a significant effect on breaking performance, especially in emergency braking. If you aren't getting enough braking power on the rear wheels for example, the rear could kick out. I'd suggest looking at the options for doing this calibration. It's only one peice of kit you need to make it possible.

 

[duece71]

If you don't intend to measure the LSPV pressures, your best bet is as you said try and mark the current position and match it. That did work reasonably well for my swap over. Obviously this assumes your current settings are right though, which may not be the case if you've done a big lift.

Honestly I suspect most people's 80s have LSPV settings that are significantly off. It can have a significant effect on breaking performance, especially in emergency braking. If you aren't getting enough braking power on the rear wheels for example, the rear could kick out. I'd suggest looking at the options for doing this calibration. It's only one peice of kit you need to make it possible.

Thank you for the reply. I have an HDJ81 with the stock lift…..it is 1990 model year (JDM) and suspect you are correct about the setting.