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My Salisbury Disc swap and brake system customization

18734 Views 96 Replies 20 Participants Last post by  Spencedpete
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Long story short I wanted to go to Disc on my Sals and keep the drum length axles and wide spaced hubs. I ended up creating an entire new braking system using a mix of Rover and GM parts due to cost and performance issues.

Lets start with the drum to disc. I wanted to stick with solid rotors all around for parts commonality and cheapness

****if you use these instructions you WILL NEED to replace the master cylinder as it wont have enough volume to operate the rear 4 piston calipers*****

I ordered or purchased:

FRC6139 (used from Adam's old axle) This is a wide spaced front disc hub for a 90/110 from 1983-2006
Solid Rotors front x4
RTC5572 x2 RH front solid rotor caliper
RTC5573 x2 LH front solid rotor caliper
Sfp000260 x2 Pads set for above calipers
Rtc5001 x2 retaining pin set for calipers
RTC3511G x2 Twin lip hub seals
FRC3988 x4 drive flange gaskets
Timken SET37 wheel bearings x4 from amazon
Stick of Lucas X-tra heavy duty green grease from walmart
and
Red winches 4 piston caliper bracket for rear axles
Rear Axle Disc Brake Conversion - Landrover Defender
Russle speed bleeders 639630 m10x1x33
Russell 639630: Speed Bleeders 10mm x 1.0 | JEGS


****the red winches bracket is made for Rover stle rear axle but will work with modification for Sals (important later)****


Steps:

Install speed bleeders into all calipers
Remove rear wheels and place truck on axle stands
Remove drive flange bolts and axle circlip
Remove drive flange and slide out axle
Remove drum retaning screw (may have to be drilled out)
Slack both adjusters on the backing plate with 13mm deep 6 point socket
Remove drum ( may need to be hammered off)
Loosen 11mm brake line fitting but leave in place on wheel cylinder
Bend back lock plate on the outer hub nut
Remove outer hub nut
remove lock plate
Remove inner hub nut
Yank entire hub assembly and put aside
Remove the six 17mm head bolts and nuts around the center of the stub axle (nut on the outside face of the axle flange)
Now remove brake line from the wheel cylinder and cap it with a rubber plug to avoid a mess
Tap or yank off backing plate
Keep the round bolt head spacer part # FRC3147
Put the fresh races and newly greased bearings into your FRC6139 front disc hubs and install the rear hub seal as deep as it will go, lips facing out
Install the new rotors onto the hubs with fresh lock washers or red locktite (or both)
Cleanup the stub axle with some red scotchbrite pad then brake or carb cleaner
Lightly grease the stub axle to aid assembly
Pack grease into the lips of the rear hub seal
Cut FRC3147 (spacer we kept from the dum setup) into two pieces so you have two equal sizes spacers with three bolt holes each, stack these together.
We will use these spacers to mount the Red winches bracket
With three fresh long bolts and nuts from the Red winches hardware kit mount the bracket on the 2o'clock position on the axle
Use the thick and thin washers from the kit to align with the hub and rotor combo
Slide hub and rotor onto the stub axle (may need to wacked with a piece of wood or a deadblow as the new bearings are a tight fit)
Install one of the hubnuts enough to keep it in place
Install one of the calipers with the included hardware from the red winches hardware kit
Eyeball that the caliper is square to the rotor and centered over the rotor, if not remove or add washers to the red winches bracket and cut up spacers
(My truck only needed one thin washer on each bolt for the caliper to be dead center)
Now remove the hub, rotor, caliper
Install the rest of the bolts and tourque to spec adding loctite
Reinstall the hub, rotors, caliper, ect
Install hutnut, locking plate (replace if it is really jacked up) and outer hub nut
Install axle shaft
Install drive member and circlip

Sit back and relax you are 1/2way there !

****TAKE NOTE on the short side of the axle you will need to notch the lower shock mount by 3/8 of an inch to allow the bracket and caliper to fit***


You have a decision to make now. you can leave the stock hardlines in place or replace them with flexlines and banjo bolts. I opted to move to flex lines as the hard lines are very close to the coils and the banjo will fit tighter and be more resistant to abrasion, AND it makes bleeding the nearly horizontal calipers much easier.


For my rear flex lines I used parts from pegasus racing:

1x 3-18-S-B 18in an3 flex line with swivel fitting one side and banjo on the other
1x 3-40-s-b 40in an3 flex line with swivel fitting one side and banjo on the other
4x 3241-3/8 soft copper 10mm or 3/8 crush washer
2x 3242-003 banjo bolt 10mmx1 short
2x 3265-16 male 10mmx1 convex to an3 male adapter


Frankly I measured the lines two times and the are still a little short so you can add 3-4in to the line lengths to give yourself more room.

The banjos will need to be shortened by about 5mm to avoid bottoming out in the caliper, i used a cutting disc to do this

Put the metric to an adpaters in the "T" mounted on your axle diff cover
Install the shortened banjos with crush washers finger tight
Route flex line to the "T" and tourque
Now tourque the banjo bolts


OK 75% of the way there !

***From this point on im going to assume you know how to identify and create brake line nuts/flares/ect***

I wanted to reaplace the absolute garbage LR booster options and the garbage masters. After some research I found that a universal style 3 and 3/8 square pattern hot rod/chevy style brake booster will fit the Defender pedal box with minimal mods.

I settled on a 11in dual diaghpram brake booster as its was the largest I could find and that would fit my RHD truck, LHD may be different.
I also decided on a Corvette syle 1 1/8 in dual circut master. These are widely avialable but, make sure to get one rated for disc/disc applicaitons. Disc/Drumn versions will have a 10lb residual valve built into the rear circut that will cause the rear discs brakes to drag.

Booster
100% Brand New Universal 11 Dual Diaphragm Zinc Brake Booster Hot Rod Street | eBay
Master:
Tuff Stuff Performance #2071NB - TUFF STUFF Performance Accessories
You can also just buy a combo unit with a Dual 8in or dual 9in booster. All will fit and work, when i first built this i used a dual 8in to conserve space (that i didnt need to) and it worked 95% as well as the dual 11in
For example:
Tuff Stuff Performance #2124NB - TUFF STUFF Performance Accessories
I also added a wilwood 2lb residial valve to the rear circut only. I assumed that the nearly horizontal rear caliper mounting may cause issues with fluid runback. This wasnt the case but it cant hurt.
https://www.summitracing.com/parts/wil-260-13783/overview/
And to top it all off I used a SSBC single circut bias valve to control the flow of fluid to the rear brakes. Since the massive calipers have insane stopping power,if the truck is unloaded or not towing they can lockup to easily, this allows for adjustment of the rear circut bias(power).
Buy Universal Aluminum Adjustable Proportioning Valve for Rear Brake Bias at SSBC


The Steps for install:

Remove round covers from the side of the pedal box
Remove cotter pin from pedal arm pin
Push pin out and let fall to the floor of the truck
Collect up the pin, cotter and the heavy washers, put aside
Remove brake lines going into the stock master, note the position
remove 17mm nuts holding stock master to booster
remove stock master
remove 4 nuts holding stock booster to pedal box
remove vac hose from booster
remove booster
Measure the height of the pedal rod clevis ont the stock booster and note it
Using cutting disc cut off the clevis from the stock booster flush with the rear of the clevis
Discard stock booster
Place clevis in a vise and centerpunch the rear of the clevis
Drill with 21/64 or similar size
Tap clevis for 3/8-24 (fine thread)
INstall tapped clevis to aftermarket booster and check for height
Aftermarket booster rod will have to be trimmed aby about 5mm height to allow for pedal assembly and pin to line up
Remove clevis, mark and trim rod
INstall 3/8-24 jam nut then clevis with blue locktite
MEasure height then tourque into place
Aftermarket booster is now ready to mount
Looking that the defender pedal box you will see that the inner unused bolt holes are reeeeealy close to the bolt pattern of the aftermarket booster.
Using a unibit open up the holes and test fit the booster until good to go.
Install aftermarket booster onto defender pedalbox with opened up holes
Install pedal arm pin, washers and cotter pin after greasing them up.
Using a grease pencil or girlfriends nailpolish mark the end of the boosters actuator rod (part that pokes into the master)
Slide new master onto the booster then check that your booster and master are mating correctly, you should now have paint or grease on both the actuator rod and the master
If you do not have markings on both sides adjust the actuator as needed (some are threaded some need shims)
Create your required brake lines and fittings
I plumbed a 2lb resudial valve into the rear circut, this is optional
I also plubmed the SSBC brake bias valve ****AFTER**** the LR PWDA valve mounted on the bulkhead (see pics)
You plumb this after to avoid the PWDA from indicating a pressure issue on the rear circut.
IF you havent already rebuilt your PWDA now is a good time to (see my other post on this subject) or remove it, your choice
http://www.defendersource.com/forum/f6/fyi-pwda-valve-116281.html
Bench bleed your new master then install into the booster
If you have the old style coolant overflow tank it may need to be moved over an inch or so, or just temporarly removed to install the master.
Now hook up you new lines and bleed your brakes!



DONE !!!!!!


Phew that was alot to type. post or PM with questions

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I got the Eastwood flaring tool and watched their videos. its slick.
I bought that one to, haven't used it yet.

I haven't done brake lines in over 10 years and I'm a dunce when it comes to fittings. I think I'll just bring my M/C in with me. When I measure the M/C it's got a 1/2" and a 7/16" holes, so 1/2"x20NF and 7/16"x20NF I figure. I assumed the bigger one closer to the booster is the front, am I wrong??? It's the one listed in the first post by Napalm.

Thanks again,
Sean

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Has the fitting sizes



Has the port locations
Thanks, I should've listened to Roadworn lol.
Man, finding m10x1 fittings locally is tough

Sean
Man, finding m10x1 fittings locally is tough

Sean
I could not find those anywhere in Santa Fe, had to order online. :-(
3/8x24 are almost identical. I used standard 3/8 fittings on mine

if you are really in a bind: go to ANY autoparts store and just buy the shortest premade metric brake line and take the fittings from that.


EDIT: I think? its been a while
I never even thought of changing everything, I guess I only need 6 female and 4 male to connect the flex lines and go into the calipers.

thanks again
Sean
pretty sure its 3/8-24 with an SAE inverted flare. but it depends on the master you have, 1967 Corvette master cylinder features a 1/2-inch thread front port and a 9/16-inch thread rear port..
Okay, just to be sure, the 1/2" port is for the front brakes and the 9/16" is for the rear or is that just the orientation on the MC you mean??? I assumed the bigger one would go to the front. I'm gonna start today, I was too aggravated from driving around yeaterday lol.

Sean
Second PDF in the link above tell you what they are and they exact size
Sorry I didn’t see that. I’m so over cautious about this now that I have my son
No sweat man , this stuff can be confusing for sure
that good to hear man. Did you end up taking out the Gvalve?
oldy, but I was thinking about this the other day.

Did this conversion awhile ago and the back rotor don’t seem to be wear as well as the fronts. they don’t seem to be seeing much pressure from the pads.

I did the conversion with the adjuster for the rear pressure and was wondering if I should have deleted the valve that goes to the rear wheels.
I think you referring to the G valve that I reference above. I'm not really sure as I've never worked on one but it is designed to reduce pressure to the rear.

In my setup I actually run a rear bias valve adjuster so that I can turn down the pressure on the rear brakes without it and without a G valve I would lock up the rears incredibly quickly. Dangerously quickly on the street.

So now I run a bias valve that is adjustable that reduces my pressure to the rear brakes essentially the exact opposite problem that you have.



Edit: I've also switched to a much cheaper dual 8-inch booster as the dual 11 that I had in there failed. Breaking power is still excellent
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I think you referring to the G valve that I reference above. I'm not really sure as I've never worked on one but it is designed to reduce pressure to the rear.

In my setup I actually run a rear bias valve adjuster so that I can turn down the pressure on the rear brakes without it and without a G valve I would lock up the rears incredibly quickly. Dangerously quickly on the street.

So now I run a bias valve that is adjustable that reduces my pressure to the rear brakes essentially the exact opposite problem that you have.



Edit: I've also switched to a much cheaper dual 8-inch booster as the dual 11 that I had in there failed. Breaking power is still excellent
Yeah, I followed your lead and did the same thing. only difference was I left the G valve.
Defnitely improved my braking, but I notice the rear brakes don’t seem to be wearing nearly as much, and when I play with the bias valve it doesn’t seem to change anything.
Removed the g/valve made a big difference,
the rears are definitely working a lot more.
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Did any of you have any issues with the drum brake axles (vs disc brake Axles) after this conversion. I used the forbyn brothers hubs and vented 90 disc's for my version of this conversion and the drum axels are a bit longer than needed. after 3oo miles It has just started to make a whining/humming sound when I make left turns. never did that before the conversion. new bearings and seals using the wet end approach vs sealed hubs. could be unrelated but awfully coincidental.
Roadworn - did you end up going with the short disk-style halfshafts? Did that solve the issue? Is the Forbyn kit built for the early "long" drum shafts or the newer "short" disk shafts? It would make sense to have them work with the more readily available short shafts...
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