Tearing down my HJ47 troopy (1 Viewer)

[gswest]

I've used POR15 before and It would stand up better that the Rustoleum paint I'm using fo sure. I cleaned the booster up and repainted it yesterday assuming there wasn't any paint that could hold up to the brake fluid. That brake fluid is some nasty stuff! I'm hoping the leaks are over for now. I've ordered a new Master cylinder (Aisin), and should have it by Monday. I'll have to look back, but I thought I replaced the master cylinder back when I was putting it back together; I'm not positive though. But thanks for the input Tom.

 

[gswest]

I got the new brake master cylinder in and installed. I attempted to bleed the system again, with no success. I see no leaks; the master was the only leak, so what am I missing? I already took the front brake drums off to see if there was a obvious leak or problem; nothing. So today I took the rear tires off and currently am struggling to get the left rear brake drum off, but with no brake fluid showing on the inner wheel, I can't imagine it's leaking. I can't stand the idea I will have to take it to a shop for what should be a simple process; bleeding the brakes. I must be missing something. I've bled the brakes many times with not issues. I did drive it to work yesterday; good thing nobody stopped quickly in front of me! They'd been re-ended!

 

[lostmarbles]

I got the new brake master cylinder in and installed. I attempted to bleed the system again, with no success. I see no leaks; the master was the only leak, so what am I missing? I already took the front brake drums off to see if there was a obvious leak or problem; nothing. So today I took the rear tires off and currently am struggling to get the left rear brake drum off, but with no brake fluid showing on the inner wheel, I can't imagine it's leaking. I can't stand the idea I will have to take it to a shop for what should be a simple process; bleeding the brakes. I must be missing something. I've bled the brakes many times with not issues. I did drive it to work yesterday; good thing nobody stopped quickly in front of me! They'd been re-ended!

The rear drums are more of a pain to get off than the front ones because they don't have any threaded holes to use for extraction (by inserting screws/bolts).

I use a heavy soft hammer to tap them out but you have to work uniformly around the drum.

Once you see them moving, even just a little bit, you can relax a bit. And then it is just a matter of lifting each side evenly to get it right off the hub/studs/shoes.

You've certainly got to watch that you're not trying to lift the shoes too (and this will happen if the adjusters aren't slackened off enough or if you're not lifting the drum off evenly). If you think this is happening it is best to tap the drum right back down until it's seated again and start again.

As for bleeding your system, there are so many threads on that that I'm reluctant to get into another discussion on it. It seems that we all have trouble at times and most of us muddle through somehow ... with some (like me) finding a method we swear by but that is probably linked to the quality of our tools (such as my vacuum bleeder) or our vehicle's position (mine's always in my driveway and poking slightly uphill) or whatever (which means that when others try what they think is the same method they may not have the same success..)

Good luck Scott

 

[gswest]

Thanks Tom,
Turns out my back drums do have the holes to use the bolts in. So, I got the right drum off and am cleaning up the grime so I can verify there's no leak. As I said before, there's no fluid showing, so a leak there is unlikely. There's so much built up brake dust and grease, I have to look at it anyway. I'll look at all the posts dealing with bleeding the brakes again. I got a vacuum bleeder that works off my compressor, but it appears it's drawing air through the threads on the bleeders.
Thanks,

 

[lostmarbles]

Thanks Tom,
Turns out my back drums do have the holes to use the bolts in. So, I got the right drum off and am cleaning up the grime so I can verify there's no leak. As I said before, there's no fluid showing, so a leak there is unlikely. There's so much built up brake dust and grease, I have to look at it anyway. I'll look at all the posts dealing with bleeding the brakes again. I got a vacuum bleeder that works off my compressor, but it appears it's drawing air through the threads on the bleeders.
Thanks,

That's interesting that you have threaded holes to aid brake-drum-extraction on your rear drums. Here is the RH-rear on my 1979 BJ40 showing none:

These rear drums are much smaller and lighter than the monsters on the front of my BJ40.

As for your brake bleeding problems, often the little holes in the nipples get blocked with rust and other crud.

So I've found twiddling a small drill-bit through that little angled-hole at the pointed end can help clear it out and thus at times make my vacuum bleeder perform more effectively.

Without a decent fluid-flow (from your vacuum bleeder), air bubbles are likely to back-travel through the escaping fluid to return to their high-point entrapment-locations (rather than getting sucked out).

 

[gswest]

I'll try that trick to clean out the bleeders.

 

[lostmarbles]

...I'll try that trick to clean out the bleeders.

Thanks for the pic.

I'm guessing your threaded extraction holes were an improvement Toyota introduced in Aug 1980 when they performed those other modifications that got the handbrake to work the rear shoes (instead of having it work an extra drum brake on the driveshaft).

 

[gswest]

I have the emergency drum brake on my on my drive shaft also, but someone may have replaced the rear brake drums at some point. I did find a leaky wheel cylinder on the left side, the right side wheel cylinder was replaced early on when I got the truck. Luckily, I had a replacement sitting around (Miracle), so that went in and I went ahead a got the drums turned (resurfaced). Tomorrow we'll see if the air will evacuate.

 

[scrapdaddy]

Please disregard if already done, but what about bench bleeding the master before hooking up the lines. Gets the air out of the master.

 

[gswest]

At this point I'm fairly certain that the air is out the brake lines. It still takes 3 pumps to get brake pressure. Someone on another brake bleeding post here pointed out that if the adjusters are not correct, it will take a couple of pumps to get pressure. I'm at the point that the leaks are solved and still it takes 3 pumps to get pressure. When I took the front axles out, I backed off the brake adjusters and even though I think I adjusted them back correctly, they must be too loose. It's the only thing left that isn't sorted out; possibly. So, I get to jack the front end back up and do the front brake adjustment process again. It makes sense, because, after 2 or 3 pumps I have good pressure. A good mechanic would not have had these issues. I'm learning every day!!

 

[Weber Sarge]

A little trick when adjusting the brakes - while it's on stands , spin the wheel or drum as hard as you can with a bar across the lugs (don't get nuts , just turn it with some force) and have an assistant hammer the brake pedal . This will seat the shoes into their correct spot better and get them aligned into the drum . Do this a few times and keep adjusting , you'll find you have to go a few more clicks than previously thought . It's all about seating those shoes in the drum ...

You can also drive it a bit , and re-adjust as that will basically do the same thing .

Sarge

 

[gswest]

Thanks Sarge,
I'll try that trick tomorrow.

 

[gswest]

Guys,
I went to re-adjust the brakes starting in the front and found the front right would not adjust beyond a few turns on the front right forward wheel cylinder. So, I took the wheel and brake drum off. Sure enough, the right front forward wheel cylinder was locked up. I couldn't turn the adjuster with a hammer and chisel. It also showed brake fluid oozing out. I again lucked out because I had ordered some of these brake parts at the beginning of my tear down. I had a replacement wheel cylinder for the one that was leaking and locked up. I put it in and will re-bleed the system tomorrow. I think I got it to the correct adjustment, but will drive it around the block and then re-adjust it as Sarge mentioned. Holy crap! This is crazy, and I'm just now realizing, the adjusters turn in different directions to tighten or loosen the brake pads. Apparently it's not always clockwise to tighten. I only figured this out by working with the new parts I have on the shelf. I don't think the manual I have talks about the direction to adjust the brakes out or in?? I probably initially loosened one of the pads all the way out assuming they all adjust in the same direction. Learning!

 

[lostmarbles]

.... I'm just now realizing, the adjusters turn in different directions to tighten or loosen the brake pads. Apparently it's not always clockwise to tighten. I only figured this out by working with the new parts I have on the shelf. I don't think the manual I have talks about the direction to adjust the brakes out or in?? I probably initially loosened one of the pads all the way out assuming they all adjust in the same direction. Learning!

With my brakes (when lying under the cruiser and reaching in with a stubby screwdriver through the slots in the backing plates) I always need to push the notches on the adjuster wheels INWARDS TOWARDS WHEEL/AXLE-CENTRELINE to expand the shoes (to take up wear).

This same rule applies to every single slot and obviously I push the "notches" in the other direction (outwards) to loosen off my adjustment.

 

[gswest]

Thanks Tom,
I might have figured that out after another week or two of frustration. Much appreciated!

 

[lostmarbles]

Thanks Tom,
I might have figured that out after another week or two of frustration. Much appreciated!

Here is your RH-rear:

And here is my RH-rear:

Our brake shoe/cylinder layouts are quite different as you can see...

But it still looks like clicking your adjuster-wheels inwards expands your shoes and clicking them outwards contracts your shoes - so I'm guessing Toyota used this as a general rule.



PS. When I saw your rear shoes/cylinder layout I automatically thought it was related to Toyota changing the layout to make the handbrake work those shoes (rather than work shoes on the rear driveshaft). They made this handbrake change on most BJ4# series (which is the series I'm most familiar with) in August 1980 but I now see they didn't apply the same change to other models (or even ALL BJ4# series in all markets) till later or not-at-all.

 

[gswest]

Your rear brakes look like my front brake set up. Two wheel cylinders versus my one in the back. I would think 2 is better.
I did get the brakes adjusted finally; I must have adjusted them in the wrong direction initially, but the one wheel cylinder was locked up and leaking so I had to deal with that anyway. This was really the last thing I had planned for the truck for a while. Down the road I thought maybe a 5 speed, maybe power steering? But, there's another problem I discovered today when I took it for a test drive after adjusting the brakes. I hadn't tried the 4 wheel drive function since swapping the differentials. When I put it in 4 wheel drive today I got some serious vibration coming through the transfer case shifter. Something obviously isn't right with either the transfer case or the front differential. The first thing that popped into my head was the front diff isn't the correct ratio (3.70). But actually, I haven't tried the 4 wheel drive system since I got the truck back on the road. So I don't really know if this problem is from the differential swap or if I screwed something up when I re-assembled the transfer case. I know one thing, I don't want to take that diff out again. The question is this: is there a way to verify the differential ratio of the front diff without taking it back out?

 

[lostmarbles]

... The question is this: is there a way to verify the differential ratio of the front diff without taking it back out?

4.11 means turning the wheels on that axle once (simultaneously, such as by rolling the vehicle) should turn your driveshaft 4.11 times.

So you could do some maths, put bits of masking tape on wheels and driveshafts as markers, and then push your vehicle (in 2WD neutral) along flat ground for say 4 wheel-revolutions and note how many times each driveshaft turns.

Rather a pain but easier than opening things up



I think it is better to go for more than one wheel-revolution so as to gain more accuracy in your results.

 

[gswest]

Thanks Tom,
If I put the truck on jack stands and put it in 4 wheel drive mode, I should be able to see if the front and rear tires are turning at the same revolutions per axle revolution? Is that more complicated than it needs to be? I want to eliminate the diff. ratio question before
I start taking things apart. I know if they are not the same, my transfer case will get destroyed, right?

 

[lostmarbles]

Thanks Tom,
If I put the truck on jack stands and put it in 4 wheel drive mode, I should be able to see if the front and rear tires are turning at the same revolutions per axle revolution? Is that more complicated than it needs to be? I want to eliminate the diff. ratio question before
I start taking things apart. I know if they are not the same, my transfer case will get destroyed, right?

I can remember this discussion occuring in other threads with no-one mentioning the problems caused by the spider gears in the diffs.

Remember that when you have both wheels off the ground, rotating the left wheel may make the right rotate in the opposite direction (and vice versa) without rotating the driveshaft at all.

So relating this to your plan ... with all four wheels off the deck and in 4WD, turning the driveshafts (which will be locked together to rotate in unison) may make any wheel on one side rotate more than its mate on the other side. (If you have diff locks, you could engage them to stop this.)

So best to jack up only one side I think. And I think this'll mean that those two wheels off the ground can be expected to rotate TWICE as many times as you would expect. (Hopefully someone will correct me if I'm wrong about this or if I'm overthinking it all and there's a much simpler way.)