Drum to Disc Brake Conversion: 1986 GLHS

[bryan6376]

Hi Folks!

I know this has been discussed many a time here. I'm just hoping for a few specifics. I bought a Drum to Disc Rear Brake Conversion kit from an enthusiast on Facebook. However, I've never done a Drum to Disc Conversion before, so I want to make sure I don't screw anything up. I have a 1986 GLHS inherited from my father-in-law, and I'll be converting the Rear Drum Brakes to Discs. Here are the parts I have for the conversion, as well as the basic instructions from the seller:

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COMPLETE SOLID REAR DISK BRAKE UPGRADE (89 Style)
For all Chrysler K-cars from 84-93 such as Omni and Charger, Daytona, Shadow, Spirit, Lancer, Laser. Completely refurbished, ready to install and run, solid (non-vented) rear disk brake set-up, complete with the following:
(2) OEM solid disk brake hubs/spindles and mounting hardware
(4) New Timken inner & outer bearings & new grease seals
(2) Caliper backing plates (left and right)
(2) OEM calipers (left and right)
(4) New internal emergency brake shoes
(2) New Wagner rotors
(2) New rubber caliper to bracket hoses with copper sealing washers
(2) All solid brake line mounting brackets and hardware,
(1) All internal small pieces (adjusters, springs, e-brake levers)
(1) Set of semi-metallic disk brake pads
(1) Correct OEM solid rear disk proportioning valve

What's not included:
Metal lines from caliper rubber hose to body rubber hose, body specific parking brake cables. The metal line is the line that goes across the swing arm. Just buy pre-flared brake line at NAPA/any parts store and bend your own. But all the mounting hardware for this line is included!

This is the much preferred later, 89+ style rear disk brake design with the internal emergency brake system that uses the small brake shoes for emergency brakes, not the style that uses the caliper as the emergency brake.

Both left and right sides have been completely disassembled, cleaned refinished and reassembled. Bearings replaced with high quality Timken brand bearings and repacked with Lucas synthetic red grease, rear bearing seals replaced with quality Timken brand. Calipers operate perfectly and have excellent boots. Caliper brake pad glide rails are in excellent/perfect shape.
New rotors ARE included also!
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Here is a link to a few pictures of my conversion kit.

Has anyone done a conversion similar to this one and documented it, either through video or just a set of photos? I know it's supposed to be an easy bolt on, but I don't want to screw anything up. I'm particularly interested in:

a.) How easy/challenging it was to install the new proportioning valve.
b.) How the emergency brake cables attach.
c.) Will I need to buy any pre-flared brake line to make this work?
d.) Any photos/videos of the process you're willing to share?

Thanks for all your help. This has been a fun journey, and I've really enjoyed working on this car!

[chromguy]

a.) How easy/challenging it was to install the new proportioning valve.
This is straight forward on my P body, I would coat the fittings with ATF or your favourite penetrating oil daily for a week or so, if possible. 30 year old corrosion is not fun. I would recommend you pick up a Factory Service Manual (FSM are invaluable and commonly can be found on Ebay) https://www.ebay.com/itm/Chrysler-Se...cAAOSwVv9cekqb

b.) How the emergency brake cables attach. My P body was nearly identical to the drum location. I used the same cable but needed to cut a few inches off the spring for the shoe

c.) Will I need to buy any pre-flared brake line to make this work? You can make these if you wish. on a 30 something car you will find all sorts of surprises. Use ATF to soak the brake fittings to eliminate damage. It would not hurt to have spare lines ready.

[cordes]

I think the L body cars already have the most front brake bias. I would double check it, but if that's the case, I wouldn't swap the proportioning valve.

You may want to familiarize yourself with making flared lines. It's not hard and puts you in a position to do whatever is necessary to make it work.

I don't have any videos for the rear brakes, unfortunately. Just the fronts.

[Goforthz28]

Nice Find! Is the guy selling multiple sets or did you just stumble upon the right guy selling one of his projects??

On to you questions. Yes, your best bet is to go into the hydraulics with the expectation of replacing all hard tubing on the swingarm. Pick up a flaring tool set. Do yourself a favor and dont buy the cheap cheap crappy sets, theyll only make the pain worse. And then pick up 10’ of hardline and flare fittings. All of this is cheap, and youll be a hardline stud by the end of the project. As mentioned earlier, attempting to bend and flare the 30 year old line will only cause anxiety.

i know you will be attracted to stainless... but again, this will also cause you anxiety. It is much much harder to work with, especially with cheap tools.

the Ebrake cables... i bought a set of new (parts house) cables for a disc brake daytona. I removed the cables from my drum omni, then i sat them next to each other and modified the daytona lengths to fit. The trick is to cut the jacket tube in a fashion that wont cause damage to the cable in the future, and to retain the seals to keep debris out of the tube. Putting the crimps back on the end isnt bad with manual crimpers made for safety cable.

good luck!
send pics!
~Mark

[chromguy]

Many people have commented that Nickel-copper is great to work with DOT approved and does not rust

[bryan6376]

Thanks for all the feedback.

I'll pick up about 20' of nickel copper line. Extra won't hurt.

Auto zone has a free flaring rental kit. I'm seeing 3/16 inch for brake lines in my manual, but can someone make sure I'm not misreading that? If so, I'll grab the SAE flaring kit from Autozone.

If you'd like me to pass on the name of the gentleman I got the front brake kit from, feel free to DM me. He's on Facebook and puts together the parts to sell about twice a year.

I'll definitely take pictures and videos as I go through. Thanks for all you help!


Sent from my iPhone using Tapatalk

[cordes]

It should be 3/16ths line.

[Dr. Johny Dodge]

use the spindles from YOUR car
if there are shims between the spindle and trailing axle install them again in the same position
thus the rear allignment should at least still be close to correct

if you need to buy the two short parking brake cables BUY MATCHED SET FROM SAME MANUFACTURER

if you buy one moog and one wagner cable .. for instance , you're GOING to have a B of a time adjusting the P brake..
because the cables will differ slightly in length..

there is the issue of the rear discs locking and the rear end becoming tail happy..

this happens in both conversions and factory built cars

I had an 87 shelby z .. stock rear disc .. tail happy car even with the as built 4 wheel disc and whatever prop valve cryco used

my 86 TZ , with 89 solid rotor 89 style rear disc / inner drum.. stock drum prop valve .. was the exact same..
_ I did not bother to change the prop valve , knowing there was no point in it

I think bigger brakes up front would MAYBE help.. the 87 shelby doesn't have them in the day..

BUT I think the rear locking / tail happy thing is more about the lack of weight in the back end , in addition to the sudden concentrated pinch point of a rear caliper..

I think , and want to try the bigger caravan rear drums myself.. thus eliminating that pinch point on the rear rotors

hey .. galaxy station wagon brakes worked for 'Ol shelby back in '65 on the gt350