Rigger's disc brake conversion

[Rigger]

I also spent some time in a few junkyards today. Scared up some brake lines from a Tacoma and from an FJ60. I will need some advice on what to do.

Here is how I understand the routing: one line from master to front axle, and another line from master to rear axle. I think I should probably not re-use any old lines. Are you guys jiggy with that?

(I found that set of tuna cans, too. It was a mid-60's FJ40, nicely hidden away. I wonder what them tuna cans are worth.)

 

[Poser]

Glad you got your goodies!

You should see another box shortly!

On the "tuna cans"....Pretty sure you can still get them new from Toyota....

 

[Degnol]

I'm sorry, I do not know the bore diam. I will be picking the master up tomorrow or Friday maybe, so I can measure it and post it up.

My reasons for selecting the 'vette master cylinder are simple and unscientific: It worked for some of the other guys and it looked easy. A few guys recommended I do this in some other way, but in the end I chose this one. I am hoping for the best.

BTW, I have blown my initial budget. I made a few wrong turns and I had a couple of hard luck hits. These cost me. When this is all over, if I am not too embarassed by my missteps, I may post up my costs spreadsheet. Right now, I can't!

I run the Corvette master and IIRC, the bore is 1" or 1 1/8" and the pedal effort is h-a-r-d. I bought a 7/8" bore master from Wilwood but have not yet installed it. It should yield less pedal effort, but if it is still hard, I'll redrill the brake pedal arm (where the pushrod yoke attaches) a little higher to increase the moment arm and save my scrawny legs.
In any case, the system I have now has worked well for 4-5 years. The reason I want more pressure is that I also have a trailer project that will be pulled by the '40.
GL with your conversion!

Ed

 

[Rigger]

I run the Corvette master and IIRC, the bore is 1" or 1 1/8" and the pedal effort is h-a-r-d. I bought a 7/8" bore master from Wilwood but have not yet installed it. It should yield less pedal effort, but if it is still hard, I'll redrill the brake pedal arm (where the pushrod yoke attaches) a little higher to increase the moment arm and save my scrawny legs.
In any case, the system I have now has worked well for 4-5 years. The reason I want more pressure is that I also have a trailer project that will be pulled by the '40.
GL with your conversion!

Ed

Thanks, Degnol.

I have been sort copying your master setup because I understood that it worked well. The fact that the pedal force is hard makes me want to re-think it, and maybe go to a boosted setup. Hmmm. I'd best fall back and re-group.

Your use of the phrase "moment arm" tells me maybe you are an engineer? I'm an engineer and I use that phrase often! LOL!

 

[Degnol]

Thanks, Degnol.

I have been sort copying your master setup because I understood that it worked well. The fact that the pedal force is hard makes me want to re-think it, and maybe go to a boosted setup. Hmmm. I'd best fall back and re-group.

Your use of the phrase "moment arm" tells me maybe you are an engineer? I'm an engineer and I use that phrase often! LOL!

Well......I do build bridges

Before you go and get all "booster-y", Unless you are running a V8, you'll likely encounter major interference problems with the firewall rib and the carburetor. The firewall on the boosted '40s had the brake and clutch masters offset to the driver's side and the firewall rib was shaped to go around the booster.
I think going with a smaller bore master and maybe improving the leverage will get me where I want to go. The first several vehicles I owned did not have power brakes....Hell, some had no brakes at all

 

[Rigger]

Got out today and cranked that 27mm nut off the companion flange. Pulled the flange off and cleaned it up. Removed the old seal. Never got a chance to get down and get the new one. Maybe Monday.

That's the old seal in the bag.

 

[Rigger]

Well......I do build bridges

Before you go and get all "booster-y", Unless you are running a V8, you'll likely encounter major interference problems with the firewall rib and the carburetor. The firewall on the boosted '40s had the brake and clutch masters offset to the driver's side and the firewall rib was shaped to go around the booster.
I think going with a smaller bore master and maybe improving the leverage will get me where I want to go. The first several vehicles I owned did not have power brakes....Hell, some had no brakes at all

The kid is a bridge builder! I like it!

I have had it in mind that I can buy a firewall adapter, and use a thin "pancake" type booster/master combo from a mini truck and maybe just maybe have a chance of it all fitting in the space between the firewall and the carb without having to cut that firewall rib. Has this worked for anyone? If I do this, I have no idea how to get vacuum to the booster.

But your idea of adjusting the leverage is intriguing. Frankly, I'm irritated that I didn't think of it myself!

 

[Rigger]

Discussion/questions on brake line routing:

I think I heard that the lines have to be routed from the master down hill, with no part of the line being above the level of the master. Going from the master up will make it hard to bleed things out. Is this true?

I have some salvaged lines that have those coils in them. There are 5 or so circular loops. Do these serve some sort flex purpose, or is it just in there to use up the extra line?

Does anyone know a good brand/type of clamp? I refer to those rubber insulated gizmos that clamp the lines to the frame. Do you use self-tapping fasteners to anchor these, or what?

Since I'm in the plumbing business for a bit here, maybe I should re-plumb the clutch, too. Does the clutch use the same size/type lines?

 

[3_puppies]

the "coils" are there for body to frame twist, that way no lines break

there should be threaded holes, in your frame, to attach the brake line to.

 

[Hugh Heifer]

Good write up so far! I saw the Marlin seals recently and they are beefy. Two sealing lips so leaks will be a long time coming ...

I will be going with those on my next rebuild as well

 

[Degnol]

Good write up so far! I saw the Marlin seals recently and they are beefy. Two sealing lips so leaks will be a long time coming ...

I will be going with those on my next rebuild as well

My weak Dojo has always prefered 2 sealing "lips", too.Or 4...Majora/Minora;p

 

[Rigger]

Okay, a couple of setbacks and a bit of progress.

I got a chintzy-looking Napa pinion seal. Yeesh, this thing looks bad! Definitely not Toyota stuff. I'll install it and see how it works.

My diff gasket is the wrong one! It's a Fel-pro, came in a nice box that is marked "Not returnable if box is opened". And it is too small by an inch or so on the diameter! I need to buy and install the correct seal.

When above two things are done, I can paint the axle housing.

I also notice that my master cylinder looks different from the one Degnol runs. I been kinda copying Degnol's setup. My master looks taller. I'll post up a pic tomorrow.

I got the new front rotors and dropped them off at the shop to get 'em bolted to the centers and turned in.

I got my front calipers, all preloaded with new pads.

I separated the inner axles from the outer axles using the "drop in the pipe" method. Worked great. Next, I have to put the newer shorter outers on.

Once my seals and bearings show up, I can begin re-assembly full bore!

I'll get more pics up later.

- Rigger

 

[bderrly]

I'm in the process of doing the front disc swap on my 1970 right now too and I am faced with the same dilemma regarding the booster. I just bought a booster/master cylinder from a 1991 FJ80 and unfortunately the booster is HUGE. I am really not sure how I'm going to get the booster in there with the clutch master and carb/air filter in the way. If you come up with any ideas please post them here. I'll be doing some more searching here to see if anyone else has conquered this problem. (I am a newbie mechanic myself and had an old hand tell me that switching to discs without adding the booster is not going to do much for me. I might as well stick with the drums in that case.)

 

[Rigger]

I'm in the process of doing the front disc swap on my 1970 right now too and I am faced with the same dilemma regarding the booster. I just bought a booster/master cylinder from a 1991 FJ80 and unfortunately the booster is HUGE. I am really not sure how I'm going to get the booster in there with the clutch master and carb/air filter in the way. If you come up with any ideas please post them here. I'll be doing some more searching here to see if anyone else has conquered this problem. (I am a newbie mechanic myself and had an old hand tell me that switching to discs without adding the booster is not going to do much for me. I might as well stick with the drums in that case.)

One mudder I talked to a while ago actually moved the clutch master over, cut the firewall rib off, and installed a booster and master far enough over to avoid hitting the carb/air cleaner. I am trying to avoid all the cutting and moving, so I am doing this unboosted setup. If this doesn't work for me, the only setback is the cost of the master. Everything else has to be done, anyway.

I'm not sure I agree that switching to discs won't do much. In my case, my drums are a mess, and I doubt I have the skill necessary to do a good rebuild on them. The parts alone for a drum rebuild are pretty pricey. There's lots of cylinders to monkey with, and adjusting them is, according to all the sources I have consulted, difficult and frustrating.

The UPS man brought me some more stuff today, so I am rapidly running out of excuses for sitting around on my rear. I need to get wrenching! I am on the road Friday and part of Saturday, so maybe next week, I'll get after it in earnest.

In any case, good luck to you.

 

[bderrly]

One mudder I talked to a while ago actually moved the clutch master over, cut the firewall rib off, and installed a booster and master far enough over to avoid hitting the carb/air cleaner. ...

In any case, good luck to you.

That might be my best (only?) option. Thanks and good luck on your swap as well. I'm very much looking forward to driving my cruiser again soon!

 

[Rigger]

Finally had a chance to get back out to the shop!

I installed the newer type outer axles on to my inners. Compressing those snap rings is a trick, to be sure. I found myself wishing I had a few more hands and a few more screwdrivers! Eventually got 'em on there.

I installed the new gasket at the diff-to-axle-housing interface.

I have the axle housing cleaned up and ready to paint.

I have to take the companion flange from the 1970 axle and install it on to the 1976 axle. I'll do that when I actually get into the axle swap.

Pics are new birfs installed onto inners, axle housing ready for rattle canning, and box of new seals and bearings.

 

[Rigger]

I bought a proportioning valve from JEGS.

 

[FineWynsFJ40]

Nice work!!

<hijack>A bridge builder? Nice one, Ed!</hijack>

 

[Rigger]

Here's advice: Plan your projects better than I am planning this one. After all my parts ordering, I find that I am missing two lock washers and two nuts that go on the (11 mm) knuckle studs. Yeesh! [forehead slap].

Umm, anyone got any extras?

 

[Rigger]

Axle all painted up. Started sorting thru gaskets and bearings last night. To be perfectly honest, I've sort of forgotten the re-assembly sequence. I had to break out the diagrams and study things a bit!