Brake Conversions

GOT IT!!!

Broke another screw and was in real trouble...Now to find a new seat.

 

Mine has the right side outlets.

I'm really sorry this thread was hijacked with my master cylinder questions and issues.

That being said...
Here's the MC with the seat and check valve removed.

<--- FRONT..........REAR --->


These adapters were used between the MC and brakes lines...Do I really need to replace the seat? I don't see its function now that I removed the check valve.
<--- FRONT..........REAR --->

 

I used a tap... It broke... I drilled a new hole and used a screw... It broke... I drilled another hole and used a stainless steel screw and it worked!

Now finding a brass seat is rendering impossible! I called 5 parts stores today and no MC cores on the shelves. My uncle said he might have what I need. Well see?

 

It's been awhile since I posted about my progress, that's because I'm not having very good results. I meticulously completed the front disc brake conversion and 11" drums in the back. I used the stock MC with the Wildwood 2lb valve to the discs. I have to push the brake to the floor to stop. Nothing like I thought I would experience. I expected to be tossed through the windshield. I bench bled the MC and thoroughly flushed and bled all the lines (more than once).
So I started to think my stock MC was bad, maybe I ruined it somehow when I overhauled it? I honed it but didn't get a rebuild kit.. Doh! So I took it out and ordered the Ford disc/drum MC mentioned a few pages back, it arrived today. What's interesting is, it was said in this thread to have the proper proportioning valves or residual valve(s) already in it. I'm not sure if it does? The bench bleeding instructions say to fill up the MC until fluid exits the outlets, then install the plugs (or fittings depending on your bleeding method). They also say to transfer proportioning valves (etc) to the replacement MC. I removed the brass seat and found nothing. Is it all in the piston cylinder these days? I trusted it was and installed it without the Wildwood.
This thing is huge! I had to grind a little off the CJ frame and enlarge the mounting bracket holes. I bench bled the new MC and the lines again. I took the Jeep up the road (I always test uphill) and got the same disappointing results. I turned around and pulled back into the garage, jacked up the Jeep and adjusted the rear drums with more drag. The next test was better but I still expected more aggressive stopping power. It seems the discs aren't the majority of the stopping power as they should be... Or am I expecting too much?

What's going on?

47v6 mentioned in a PM it could be non centered calipers? I've studied hard and can't figure out how to do that, nor have I read anything regarding calipers being an issue. for anyone.

FWIW... I had my daughter step on the brakes while I test spun all the tires. They stop and release allowing me to spin the tires again. I think there must be a valve of some sort???

 

- I can't find any air in the system. Maybe I need to use teflon tape during the bleeding process because a couple of the bleed valves might be giving me false readings when watching for bubbles.
- Unbelievable...I DID order the power brake MC! I bought the one Tim suggested from RockAuto but I didn't look at the "power brake" in the description. Napa's version - NMC M2168 crossed checked with your Econoline (NMC M2220). I did some reading this morning through a number of sites and it sounds like it doesn't matter. I hope so...I'd hate to order another MC! The main difference that's mentioned is the threaded outlet sizes. I don't see a problem with this...It could be just for the ease of plug and play to avoid crossing the lines...But I obviously haven't a clue!
Manual - Primary Outlet Thread : 1/2"x20...Secondary Outlet Thread : 9/16"x18
Power - Primary Outlet Thread : 1/2"x20...Secondary Outlet Thread : 7/16"x24

- I think they do but at this point who knows? The small res is plumbed to the rears and was confirmed during the bleeding process. The very large res is plumbed to the front. The new MC has the same feel as when I first tried the stock MC with the Wilwood 2lb valve to the fronts and relying on the stock 10lb in the rear outlet. I've tried to avoid any type of adjustable proportioning valve because most don't seem to have to use one. Maybe it's time to cave?

- Push rod adjustment seems perfect. I cut down the new rod a little at a time until it mounted with no free play.
- No 10lb residual inline...Hoping it's in the new MC. The stock MC had a 10lb in the outlet but as mentioned above the feel between the two MC's is virtually the same.
- Pumping doesn't help.
- After setting more drag on the rears it did feel a little better. My hope was to feel amazing braking force from the front regardless of the rears. I was under the impression that if I had the rear drag very minimal, I could see how much the discs improved my stopping, then set the rears properly. At this point looking back...My stock 10" drums on the front and 9" rears were better.

 

UPDATE
I noticed my brake lever was hitting the top of the new massive MC. I removed just enough material from the brake lever to allow the brake to travel without interference. After reinstalling the pedal lever, brackets and push rod etc. there was better pressure behind the pedal and it doesn't need to be pressed as far. The Jeep stops more aggressively without lockup. This leads me to believe the rod may have needed fine tuning. It's a long shot theory due to the fact the stock MC only felt strange after the conversion. I noticed during the most recent test drive that when coasting in neutral the brake feels pretty good, however, when I have the clutch engaged, the brake needs to be pressed down further to the floor. The shared pivot rod may be showing wear?


Maybe I've got it mostly solved? It brakes better than all the other drives but I think I was expecting near lockup braking.

Questions -
If I totally loosened the rear drums (as if they weren't hooked up)...Wouldn't the front braking be awesome? Or would it be soft?
A slight 1 to 2 pumps does seems to help after all. I don't think it's air...I've bled and bled the system. Maybe the MC has the residual valve but needs a true 2lb valve to the discs (which I can hook up) and 10lb valve to the rear (I'll have to order). What would be so bad about adding them anyway? Or maybe the adjustable proportioning valve in the rear?

How the caliper rides.