I need to fix my brakes (4 Viewers)

[6f40j9]

Early on, I threw a disc brake front end under this thing. It had already been converted. I don’t know the kit, or year but stainless lines, wilwood calipers.

I installed a new rock auto dual reservoir master cylinder (I think for a mid 80s Toyota pickup) and bench bled it first. No booster, JTO adapter.

I made some new brake lines and installed a proportioning valve so the rears would quit locking up.

I adjusted the rear brakes.

It was always a 2 pump setup to get them to work.

Last year I lost all fluid in the rear, and the fronts were worthless.

I replaced (2) rear cylinders and (2) brake lines (they had rusted out).

Bled, adjusted, bled, adjusted, etc…

Still a throw away first pump.

There’s no leaks, fluid wise that I can see.

When I jack up the front and press the brakes, they work (after one pump) so not sure why they didn’t when the rears failed.

I’d love to simplify the system if I could, as the dual reservoir get in the way of the vacuum stuff on the carb (another nightmare subject) so it got removed.

If I go to an 80 master, do I still need a proportioning valve?

 

[Shark56]

I run the 80 master on my 69 converted to 78 front axle, drum rear. No booster. I do run a proportioning valve.
Possibly need to adjust your rod going into the master cylinder a little if you need one pump to get the brakes to work. That is assuming you are sure you have no air in the system.

 

[pb4ugo]

It could be a rod adjustment. Typically, If you have to pump the brakes you likely have air in the system or the m/c isn't large enuff.

 

[6f40j9]

Gonna climb under the dash and check out the rod, see if I can’t extend it some. I probably adjusted it just enough to connect to the pedal.

 

[pb4ugo]

I think there's a pedal height spec in the fsm.

 

[Pighead]

Maybe could be your rear drums not adjusted tight enough

 

[6f40j9]

Maybe could be your rear drums not adjusted tight enough

I thought that too but I jacked it up the other day and they rub slightly so I figured they’re ok.

 

[6f40j9]

I think there's a pedal height spec in the fsm.

Possibly but it’s probably in mm and I only read in bald eagles lol.
I’ll try to find it though, good suggestion, thank you!

 

[6f40j9]

I run the 80 master on my 69 converted to 78 front axle, drum rear. No booster. I do run a proportioning valve.
Possibly need to adjust your rod going into the master cylinder a little if you need one pump to get the brakes to work. That is assuming you are sure you have no air in the system.

I’m pretty sure there’s no air but it’s a possibility. I’ve bled and bled and bled but maybe still…

 

[Pighead]

I thought that too but I jacked it up the other day and they rub slightly so I figured they’re ok.

Not tight enough.

 

[majdomo]

Not tight enough.

The drums should be about 1-1.5 clicks off of not being able to turn the drum. The FSM spec of like 4-5 clicks is waaaay too loose.

 

[6f40j9]

The drums should be about 1-1.5 clicks off of not being able to turn the drum. The FSM spec of like 4-5 clicks is waaaay too loose.

Turn the drum with the wheel on? I can’t tell 1 from a 1/2 click on these funky cylinders.
I can turn them with the tires on, but they rub all the way around. Should I barely be able to turn the wheel?

 

[6f40j9]

I adjusted the rod maybe 1/4” out, that’s as little as I feel comfortable leaving in the bracket for the pedal (~3 complete turns in).
Didn’t make any difference.

 

[pb4ugo]

Possibly but it’s probably in mm and I only read in bald eagles lol.
I’ll try to find it though, good suggestion, thank you!

If thats the case your going to struggle with Land Cruiser ownership. The key to metric to sae is 25.4mm to an inch. To confirm there's no air in the system is to carefully clamp the rear rubber brakeline with a pair of vise grips. If the pedal becomes solid then there's air in the rear. You then can check the frt. You want to stop the flow of fluid and not crush the line. I've not dealt with drum brakes for decades. Old Toyota drums are old and antiquated are a waist of my time to f with. This is a common issue and there are many threads on this subject and a lot of folks have had success, by keeping the tire on and adjust all the shoes to their max so the tire won't spin and the pistons can't move within the cylinders, then they bleed them. Once the air is out, they properly adjust the brakes to spec.

 

[majdomo]

Turn the drum with the wheel on? I can’t tell 1 from a 1/2 click on these funky cylinders.
I can turn them with the tires on, but they rub all the way around. Should I barely be able to turn the wheel?

Turn the adjuster all the way until you can't go any further (don't ramrod it, just until it stops turning), then back it off about one click of the adjuster. Do that on both cylinders and you should be ok.

by keeping the tire on and adjust all the shoes to their max so the tire won't spin and the pistons can't move within the cylinders, then they bleed them. Once the air is out, they properly adjust the brakes to spec.

On bleeding - agree with pb4's comment above. That was a key part of the bleeding process for me.

 

[charliemeyer007]

If your drums are out of round you will have brake problems. New drums aren't all that expensive. You might find a place that can turn your old ones.

 

[Jdc1]

If your drums are out of round you will have brake problems. New drums aren't all that expensive. You might find a place that can turn your old ones.

Oreilly turn mine for me. $25 or $30 a side.

 

[6f40j9]

I’ve adjusted half the cylinders to stop. (One on each wheel) I ordered the Toyota adjuster for the other two.
I’ll tighten them up, bleed them again and back them off ever so slightly.

 

[FJROSS]

If thats the case your going to struggle with Land Cruiser ownership. The key to metric to sae is 25.4mm to an inch. To confirm there's no air in the system is to carefully clamp the rear rubber brakeline with a pair of vise grips. If the pedal becomes solid then there's air in the rear. You then can check the frt. You want to stop the flow of fluid and not crush the line. I've not dealt with drum brakes for decades. Old Toyota drums are old and antiquated are a waist of my time to f with. This is a common issue and there are many threads on this subject and a lot of folks have had success, by keeping the tire on and adjust all the shoes to their max so the tire won't spin and the pistons can't move within the cylinders, then they bleed them. Once the air is out, they properly adjust the brakes to spec.

Do the above clamping of hose to alleviate all the other issues that maybe your problem. I had air trapped in my rear aftermarket cylinders that had to be dissembled in place while bleeding to burp the air. AS per 6F40j9 commented, this led me to installing rear discs.

 

[pb4ugo]

Do the above clamping of hose to alleviate all the other issues that maybe your problem. I had air trapped in my rear aftermarket cylinders that had to be dissembled in place while bleeding to burp the air. AS per 6F40j9 commented, this led me to installing rear discs.

I went to disc because FJ40 drums suck. I was tired of freeing up frozen w/c's and adjusting brakes. Along with bleeding when I had too. For yrs I was always fighting frt and rear drums. I once hired a brake specialist to work on the brakes and he got fed up with them too. Clamping the line is only for diagnosis to isolate where the air or problem is.