Drum Brake Guidance for Newbie (1 Viewer)

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Mar 30, 2016
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Location
Camarillo, CA
Several months ago I rescued a 1971 fj40 from a field where it sat for over a decade. With help from a neighbor, a fellow fj40 Enthusiast, I managed to get the engine running. I also changed all the fluids and rebuilt the Brake & Clutch Master cylinder. Next, I began to bleed the brake lines. Both rear brake lines bled fine. However, when it came time to bleed the front passenger line, I experienced some problems. As you know, there are two bleed valves on each wheel, one at 9 o'clock (front) and one at 3 o'clock (rear). The rear one bled fine, but nothing came out of the front one. I completely removed the front bleed plug, and still no fluid came out of the hole. I tried to remove the the 7" or so of solid brake line from the top T that leads to the cylinder to check for clogs, but the top Nut was frozen in place. Due to the ridge on the backing plate, I could not fit my six-point open-ended flare nut wrench around the nut. My standard wrench would not move the nut without rounding it's edges. Maybe I shouldn't even bother checking that small portion of the line, as it is probably a bad cylinder. Any thoughts and guidance would be appreciated... I would like to drive it a little this summer.

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I would take off the tee fitting from the backing plate. That would give you plenty of room to work on it on the bench.
The hose should be replaced as well.
 
Thanks for the input. Sounds like great advice. Since fluid made it to the rear bleed plug, but not the front, does that usually indicate a bad cylinder?
 
Thanks for the input. Sounds like great advice. Since fluid made it to the rear bleed plug, but not the front, does that usually indicate a bad cylinder?

Have you tried twiddling something like a needle or fine drill bit in the hole behind the nipple? That might be blocked.

I find it hard to believe the fluid isn't getting to the wheel cylinder.
 
I have a '66 and had to grind a sacrificial wrench to fit. PB Blaster is another good penetrating fluid. I second the removal of the line at the 'T' fitting tho. I would have done this, in hind sight. This was the first thing I started pouring cash into when I got my '66FJ40, but in hindsight...and FYI, when you are ready, just spend the cash on a disc brake conversion. All those wheel cylinders sure add up!
 
Amandap- Yeah, I've been looking at the different disc break conversion kits out there all afternoon. I may just go in that direction. I have a buddy who offered to give me his front axle from a 60 series... I might have to take him up on that offer. I was hoping to do a quick fix and drive it for a bit. Which kit did you get? How was installation and performance?
 
Hopefully you have a quality line wrench. After I rounded a 10mm brake line nut on my 76 I searched a found a better heavy walled line wrench. And I realized more patience and finess sshould have been employed. Not all line wrenches are created equal. The cheap one flex more.

I too have a 71 and recently removed all my brake lines without rounding the nuts. I used a small butane torch commonly used for "Creme Brulee". Don't tell my wife.:) I liked using it because the flame can be made small to precisely heat where you want. A butane cigar light would work great too. Heat the fitting and let it cool some. A squirt of penetrating oilnever hurts. I do try and wipe oil off the portion of the nut you don't want slippage on. Put your line wrench on the fitting and firmly tap all around. Now turn the wrench counterclockwise and wrap the waist of the wrench handle if needed. If it won't budge, heat it more and again let it cool. Have a good work light so you can see if the nut is about to get stripped.

To get a line wrench on the short lines near the "T fitting". Wedge a beefy screwdriver between the backing plate and T fitting. Pry just a little and the tab from the T fitting will bend. When you reinstall the clean brake lines you can bend the tab back if you so choose.

Also, I found some of my 10mm line nuts were mushroomed near the end. Not the threaded portion. Perhaps from over tightening. It was a bit difficult pull the mushroomed nuts past the threads of the female fittings. So for ease of reinstallation I carefully ground the mushroomed portion to parrallel with the threads. Obviously use some fine grit sandpaper on the tip after grinding.

HEAT is the key!
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Not a line nut but you get the idea
 
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I have a '66 and had to grind a sacrificial wrench to fit. PB Blaster is another good penetrating fluid. I second the removal of the line at the 'T' fitting tho. I would have done this, in hind sight. This was the first thing I started pouring cash into when I got my '66FJ40, but in hindsight...and FYI, when you are ready, just spend the cash on a disc brake conversion. All those wheel cylinders sure add up!
Disc brakes are the inly way to go. You will be constantly adjusting the brakes. If you live where there is rust then the wheel cylinder will rust solid. Get rid of the shoe brakes front and back.
 
I would remove the soft line, see if it is making it to the master side of the soft line. They look old and beat, they can collappse inside and prevent fluid from going through yet look OK on the outside. Sometimes they let fluid through in only one direction.
 
Amandap- Yeah, I've been looking at the different disc break conversion kits out there all afternoon. I may just go in that direction. I have a buddy who offered to give me his front axle from a 60 series... I might have to take him up on that offer. I was hoping to do a quick fix and drive it for a bit. Which kit did you get? How was installation and performance?


Still working on this conversion. I've taken about an eight year break...now back to it. I have a set( I think) of 74 axles, well the front is marked, not so sure of the rear. I'll be following these types of threads for similar info.
 

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