Disc break conversion not working

[jd4242]

I'm hoping the 96 MC will do the trick, after all, it was designed for discs on all four corners.

Speaking of Aussie lockers, because the "C" clip is such a joy to remove, I set off to invent a tool that will extract the "C" clip almost painlessly. After all, necessity is the mother of invention. When putting everything back together, I mistakenly put the spring pins in wrong, so I was forced to but my idea to work a second time. As long as you passion the "C" clip so the ends face away from you, my idea works every time .

The brakes are still not right, better but not great. I am hoping the new MC will handles it.

jager

Again 96 won t work.it was designed for a 4wheel abs, has a proportioning valve and a fitting for cruise.
C clips are easy now.one of two ways you can do, knock it half way off and spin it so it faces down and jiggle the axles and gravity will cause it to fall off.or you can make a small "L" outa a spare shim and insert it vertically then spin it to hook onto the c-clip then pull it straight out.both work 99% of the time

 

[4x4junkie]

I think something else is amiss here... I've had the stock MC on my '90 BII with a '99 Ex 8.8" for years and everything seems fine to me (if I step on it hard enough the rears start to lock up and then I can feel the RABS kick in).

Any chance the calipers got swapped to opposite sides somehow? (bleeder fitting needs to be above where the brake hose attaches onto the caliper)

 

[jd4242]

I think something else is amiss here... I've had the stock MC on my '90 BII with a '99 Ex 8.8" for years and everything seems fine to me (if I step on it hard enough the rears start to lock up and then I can feel the RABS kick in).

Any chance the calipers got swapped to opposite sides somehow? (bleeder fitting needs to be above where the brake hose attaches onto the caliper)

Absolutely no disrespect but did you adjust the pedal piston/shaft? Have you driven a first gen with the proper mc? Its not about them just locking up.I first used a 99 as that's what my rear end came out of and I can tell you there was a world of difference from the 99 and the 96 I tried first compared to the 95mc.

But yes I agree there is more to it than just the mc, but in order to properly work 100% I think a 95mc should be involved.

 

[Fossiljager]

I am embarrassed to say the calipers are on the wrong sides. I just looked under the truck and sure enough, the bleeders are below the feed line, Soy estupido . I guess it takes a B2 to know a B2. Thanks Junkie, and thank you to everyone else that has helped me with this upgrade.

I've done a bit more research on MCs for 4 wheel disc brake applications, here is what I found....
1) A disc brake caliper holds up to 4 times the fluid of a drum brake wheel cylinder.
2) The reservoirs on a Disc MC are larger to accommodate the extra fluid. (most are a single reservoir with a divider)
3) The rear piston in 4 wheel disc brake MC is larger to push more fluid to take up the volume in the caliper piston.

There are other differences but these are the ones that deal with the added volume of the disc brake caliper.

Look out, off topic comin... Junkie do you use jeep springs in the front of your Bronco?
My articulation is limited by the Skyjackers I currently have in the front. I am looking to buy a set of softer jeep springs to give me additional flex. your opinion...?

Jager

 

[Fossiljager]

Well boys, Junkie was spot on nickers tight, I swapped the calipers and shazam, worked like it should. When I stomp on the pedal,the whole truck squats and stops hard without locking either front or back. I'm guessing the proportioning valve isn't needed on disc applications. I'm kinda digging the brake I scored from Rockauto, for the price you can't go wrong. I'll be getting a set of drilled and slotted for the fronts soon. I did manage to score a set of twin piston calipers off a 95 Ranger. Together with the Brembo pads, I have all kinds of woooo.

thanks again guys for all your help, Very much appreciated!

Jager

 

[cerberusaardvark]

when i was having trouble getting my brakes to work on my 94 explorer after my 97 rear axle conversion, i realized i had let air into the hydraulic control unit. i know you said theres no abs on your truck anymore, but if the hcu is still hooked up with air in it, then you need to have it bled out at a shop. you cant bleed the hcu like you bleed the brakes. not saying thats, your problem, but when i was going round and round, that was the solution for me.

 

[Fossiljager]

As it turns out, it was my own stupidity that cause my issue. I put the calipers on the wrong side, not taking the bleeder into consideration, I had them below the inlet instead above it. (Thank You 4x4junkie!) I do not have the HCU in the truck, when I stripped the 94 X, I left that out of my Bronco II build. At the moment, I do not have a proportioning valve in the truck either, and I must say, it seems to be workng bang on. I have great brakes with no apparent bias one way or the other. If anything changes I'll certainly let everyone know. As for the proportioning valve, I can't even find one to fit a 4 wheel disc application in an X. It might be that the HCU had negated or supplanted the PV. No matter, all is fine now, I was even thinking of refusing delivery of the 96 MC I ordered from Rockauto. Even though the 96 MC was built for 4 wheel disc brake applications, w/ larger bore and seals for the rear brakes. I hate to change anything now that everything is working so well.

Now that the brakes are behind me, I'm off to build a duel battery carrier for under my truck. I'm thinking a cue from 4x4junkie and installing the batteries low and under the truck, under the rear seats to be exact. But instead accessing the batteries from under the rear seat, I'll have the carrier hinged at the front to drop down to access the batteries when needed. I also saw a cool dual battery box that would keep them safe from salt and debris.

To all my new friends,
Cheers and Gday,

Jager

 

[4x4junkie]

I've seen that happen to a few others. Someone didn't think to design the caliper mounting in such a way to prevent them fitting on the wrong sides.

Yes, I have Skyjacker's 6" lift XJ Cherokee springs under the front of my BII. IMO, they are right about perfect for a wheeling rig (not too soft, not too stiff). If you go with such springs, be absolutely sure the angles on your steering linkage are in check though. Any issues (a too-short dropped pitman arm, for example) will be greatly magnified by the softer springs not restricting the suspension's movement as much (I run a modified Superlift Supperruner (K-link) setup on mine).

Absolutely no disrespect but did you adjust the pedal piston/shaft? Have you driven a first gen with the proper mc? Its not about them just locking up.I first used a 99 as that's what my rear end came out of and I can tell you there was a world of difference from the 99 and the 96 I tried first compared to the 95mc.

But yes I agree there is more to it than just the mc, but in order to properly work 100% I think a 95mc should be involved.

Not sure your question... I have driven a 1st-gen Ex w/stock MC & drums (proper for each other), but not a 1st-gen Ex w/stock MC and discs (which wouldn't be applicable to the OP's case here anyway, where the setup on mine is).
Discs (especially ones in the rear) don't necessarily give you better stopping power than drums, they give you better fade resistance (less likely to overheat), are quicker to dry after getting wet, don't clog/freeze up with mud, and are much easier to maintain. Unless braking performance is degraded after a disc swap (brake bias thrown off causing one end to lock up too early, MC piston bottoming, etc.), I don't see the issue (maybe aside from the reservoir volume vs. piston (pad wear) thing already mentioned). WIth big tires and a short wheelbase (BII), you can't expect it to stop as well as a stock 1st-gen w/smaller or stock tires anyway (for one thing, weight thrusts down much harder on the frontend (and off the rear) during hard stops with a lifted SWB truck than on one that's not).

FWIW, past research when I did my swap indicated the only requirement be that the truck it's going into has RABS, which a '90 BII has.

 

[Fossiljager]

Thanks again for your help.... the 95 X MC is working perfectly and w/o a proportioning valve. I can't believe how much more sure my brakes feel than before.

I have 6" lift skyjacker springs in the B2 now, Problem is, they are for a B2/X running a D35, even the soft ones are stiff. My steering angles, at the moment, are spot on, no bump steer at all. I'll order a par of XJ springs next pay check. I'm also gathering bits for a 4 link in the rear. I'm up in the air as to whether I use coilovers or open coils. Coils are way less money.....

Oh I can't find you on Car Domain any longer, am I looking in the wrong place?
Send me the link if you would....

Jager

 

[4x4junkie]

Oh I can't find you on Car Domain any longer, am I looking in the wrong place?
Send me the link if you would....

Jager

Check sig

\/ \/

 

[Fossiljager]

After a couple of weeks I thought I would give you a final update on my disc brake conversion.

A run down of what I had to work with.........
96 8.8 disc brake backing plates,
rebuilt calipers,
new rear slotted and drilled rotors
New pads
new parking brake shoes and hardware.
SS feed lines
95 master cylinder
NO proportioning valve.

There has been no loss in line pressure
Brakes feel firm and responsive
There has been NO tendency for the rear wheels to lock up under normal or hard braking.
No noise coming from either front or rear brakes.

There you have it, a real world brake conversion, the good, the bad, the ugly.... who you callin ugly?

 

[jd4242]

After a couple of weeks I thought I would give you a final update on my disc brake conversion.

A run down of what I had to work with.........
96 8.8 disc brake backing plates,
rebuilt calipers,
new rear slotted and drilled rotors
New pads
new parking brake shoes and hardware.
SS feed lines
95 master cylinder
NO proportioning valve.

There has been no loss in line pressure
Brakes feel firm and responsive
There has been NO tendency for the rear wheels to lock up under normal or hard braking.
No noise coming from either front or rear brakes.

There you have it, a real world brake conversion, the good, the bad, the ugly.... who you callin ugly?

When did you get a 95 mc? Thought you was using a 96?and its only been 4days

 

[Fossiljager]

lol, really only 4 days, seems like an eternity... found the MC at local garage for $20. I canceled the order for the 96, no need for it with the brakes working so well.

 

[jd4242]

lol, really only 4 days, seems like an eternity... found the MC at local garage for $20. I canceled the order for the 96, no need for it with the brakes working so well.

Lol gotcha

 

[Fossiljager]

Yep, u did, lol, it's all good :biggthump