Are your bleeders facing up?
Build Lemonade - 1967 FJ40
- Thread starter S4Cruiser
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- Thread starter
- #442
Most definitely.
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- #443
I’ll post up a detailed synopsis tomorrow when I’m on my PC…vs iPad.
- Thread starter
- #444
Alright...here goes...
My brake setup is as follows
- front 4runner calipers (new)
- rear monte carlo calipers (new) mounted with Poser brackets
- geo metro brake booster and master cylinder
- cityracer proportioning valve for rear brakes
- all new hard brake lines bent and flared by me
- all new soft brake lines
I built a custom bracket for the booster so I did not have to cut the firewall brace. I also have a custom booster to brake pedal adapter since the booster is moved forward in the engine bay.
I have adjusted the booster push rod and triple checked to ensure correct (adjusted so there is ever so much contact of the push rod to booster piston when mounted).
I have bench bled the master cylinder multiple times and even have purchased a second master cylinder but both function the same (soft pedal).
I have bled the brakes multiple times, this weekend being the most recent, running at least 3 quarts of Valvoline dot 3 and 4 synthetic fluid. I am using a motive power bleeder plus have a helper pump pump pump hold pedal method.
I have seen lots of air bubbles through the lines while bleeding but continued until no more.
All calipers are mounted as intended with the bleeders at the top of the calipers.
I have no visible leaks from any connections.
This isn't my first time making brake lines, etc. I did this for my other fj40 it's brakes are great. Similar setup but with a fj80 master cylinder and booster. Pedal is almost impossible to press without the truck running.
Here are my thoughts...
- The geo metro master has a 13/16 bore which isn't that much smaller than the fj80 master's 1" bore.
- Others have posted here about running the geo metro master without issue.
- The geo metro master has 3 ports vs the normal 2 and has a rather funky brake line schematic (more on this in the next post)
- I do not know, haven't been able to find the geo metro booster stroke to confirm if my pedal setup is utilizing the entire available stroke (might need to remove the booster again and measure)
Here are some pics of the booster, master cylinder, pedal adapter and proportioning valve...the brake lines are a little mangled from swapping masters, etc but no leaks.
My brake setup is as follows
- front 4runner calipers (new)
- rear monte carlo calipers (new) mounted with Poser brackets
- geo metro brake booster and master cylinder
- cityracer proportioning valve for rear brakes
- all new hard brake lines bent and flared by me
- all new soft brake lines
I built a custom bracket for the booster so I did not have to cut the firewall brace. I also have a custom booster to brake pedal adapter since the booster is moved forward in the engine bay.
I have adjusted the booster push rod and triple checked to ensure correct (adjusted so there is ever so much contact of the push rod to booster piston when mounted).
I have bench bled the master cylinder multiple times and even have purchased a second master cylinder but both function the same (soft pedal).
I have bled the brakes multiple times, this weekend being the most recent, running at least 3 quarts of Valvoline dot 3 and 4 synthetic fluid. I am using a motive power bleeder plus have a helper pump pump pump hold pedal method.
I have seen lots of air bubbles through the lines while bleeding but continued until no more.
All calipers are mounted as intended with the bleeders at the top of the calipers.
I have no visible leaks from any connections.
This isn't my first time making brake lines, etc. I did this for my other fj40 it's brakes are great. Similar setup but with a fj80 master cylinder and booster. Pedal is almost impossible to press without the truck running.
Here are my thoughts...
- The geo metro master has a 13/16 bore which isn't that much smaller than the fj80 master's 1" bore.
- Others have posted here about running the geo metro master without issue.
- The geo metro master has 3 ports vs the normal 2 and has a rather funky brake line schematic (more on this in the next post)
- I do not know, haven't been able to find the geo metro booster stroke to confirm if my pedal setup is utilizing the entire available stroke (might need to remove the booster again and measure)
Here are some pics of the booster, master cylinder, pedal adapter and proportioning valve...the brake lines are a little mangled from swapping masters, etc but no leaks.
- Thread starter
- #445
Some things I am thinking may be issues.
The schematic for the geo metro master and lines is wack. The master has 3 ports:
- top port goes to drivers side front caliper
- the two side ports go to a proportioning valve that then takes those two lines and splits into 3 separate lines - passenger front, drivers rear and passenger rear
I am only using two of the 3 ports on the master and have blocked off the front side port since it is pretty close to the carb. The top port goes to the front brakes and the rear side port goes to the rear brakes through the cityracer proportioning valve.
Maybe the master has some weird dual piston design and swapping my rear brake line to use the front side port (blocking off the rear side port will help??
Do i need to get a geo metro proportioning valve and redo all my lines like the metro is setup? This would suck.
Is my cityracer proportioning valve adjusted wrong - is there a way to test it if it would cause a soft pedal?
Should I drive the truck off a cliff and be done with it!?!?
The schematic for the geo metro master and lines is wack. The master has 3 ports:
- top port goes to drivers side front caliper
- the two side ports go to a proportioning valve that then takes those two lines and splits into 3 separate lines - passenger front, drivers rear and passenger rear
I am only using two of the 3 ports on the master and have blocked off the front side port since it is pretty close to the carb. The top port goes to the front brakes and the rear side port goes to the rear brakes through the cityracer proportioning valve.
Maybe the master has some weird dual piston design and swapping my rear brake line to use the front side port (blocking off the rear side port will help??
Do i need to get a geo metro proportioning valve and redo all my lines like the metro is setup? This would suck.
Is my cityracer proportioning valve adjusted wrong - is there a way to test it if it would cause a soft pedal?
Should I drive the truck off a cliff and be done with it!?!?
Soft pedal with no air in the system = incorrect line routing or too small of a master cylinder.
For reference, 13/16" bore has a piston surface area of 0.5185sq/in, whereas a 1" bore has a piston surface area 0.7854sq/in. The 1" bore is master cylinder *significantly* larger than the 13/16" bore master cylinder in terms of surface area.
Sounds like you're being frustrated by the fact everything *should* work because people said it *did*, but it sounds to me like line routing problems with that funky geo metro MC or (more likely) your geo MC is too small.
For reference, 13/16" bore has a piston surface area of 0.5185sq/in, whereas a 1" bore has a piston surface area 0.7854sq/in. The 1" bore is master cylinder *significantly* larger than the 13/16" bore master cylinder in terms of surface area.
Sounds like you're being frustrated by the fact everything *should* work because people said it *did*, but it sounds to me like line routing problems with that funky geo metro MC or (more likely) your geo MC is too small.
- Thread starter
- #447
Thanks for responding.
So for first trouble shooting I'll swap the side ports and see if that has any improvement? Then if not I will need to decide if I switch to a non boosted master or redo all lines to follow the geo schematic?
Or cut the firewall rib and install the same booster and MC as in my grey truck/
My '80 has the same caliper setup as yours (4runner front, monte carlo rear), with a non abs 80 series master and early 90's 4 runner booster. Brakes were great with that setup.
- Thread starter
- #449
Yeah, very similar to my grey truck...that dang firewall rib support might get cut / bent out of the way.
I've put so much effort into this geo metro crap that i am hesitant to throw in the towel just yet.
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Jon, 13/16" is a smaller bore MC then any Toyota 4x4 ever came with originally. That's like Honda Civic/Corolla parts. So the pedal will NEVER be as stiff as a normal Land Cruiser or truck. And if you have larger brake capacity (larger piston swept area at the calipers, which you do), the issue will be compounded (since your ratio of MC diameter to piston diameter becomes even more skewed).
Do you brakes actually WORK ok? Like how is the stopping distance? If that seems fine and your only complaint is pedal stiffness change to a larger master. You really should have at least a 15/16" bore
Do you brakes actually WORK ok? Like how is the stopping distance? If that seems fine and your only complaint is pedal stiffness change to a larger master. You really should have at least a 15/16" bore
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- #451
I haven't started and moved truck since this weekend's marathon bleeding...but previous attempts equaled close to zero stopping power
.
On thing to consider - Nolan has had great success in many of his 40 builds using the FZJ80 non abs master, and NO booster with discs F/R. That is likely your easiest path to eliminate the need to screw with the rib?
I don't recall what booster you have, nor do I have any experience with these geo metro master cylinders. I don't know if swapping ports on your current MC will work or not.
As for what to do, you know now that you have a massively undersized master cylinder. Fix that first. Non-ABS FZJ80 master is a very good choice imho, had one on moonshine back in the day.
As for what to do, you know now that you have a massively undersized master cylinder. Fix that first. Non-ABS FZJ80 master is a very good choice imho, had one on moonshine back in the day.
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- #454
Booster is a geo metro to match the MC. It’s a two bolt mount which won’t work with the fj80 MC.
I’ve done some reading and looks like folks had to use the geo proportioning valve to get brakes to work but were never happy. Hindsight is a bitch.
Now I need to decide whether I got with a non boosted MC (and figure out how that will mount/connect to the pedal) OR cut bend grind the firewall rib and find a booster that would fit with the fj80 MC. This way I don’t have to redo a bunch of hard lines and the braking should be better overall.
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- #455
Do you happen to have a link handy? If not I’ll do some searching tomorrow.
Nolan's 45 has the manual discs, mentioned here, I'm sure you can find more details in his build thread. I know he has done it on a couple of customer builds too.
Jim C chimes in, posts 9 & 10:
- Thread starter
- #457
That awesome, thanks for the links!!Nolan's 45 has the manual discs, mentioned here, I'm sure you can find more details in his build thread. I know he has done it on a couple of customer builds too.
Jim C chimes in, posts 9 & 10:
Ok, now this is interesting. Is this as common swap? Geo metro I mean. Never heard of this before on an FJ40 but in terms of LC's I'm a newb. The metros had different engines and different body styles which had different valves. Some had rear disc. All had front disc. Seems you have 4 wheel disc. What did you use for the MC? The OEM prop valve is designed for rear drum. What do you have now?
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If you do go to manual brakes I would recommend 15/16" Master cylinder bore. The smaller bore relative to the rest of your system will allow the system more pedal travel and help with the recquired pedal pressure of manual brakes.
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- #460
I bought a dual cylinder master from Mark a while back that was his recommendation if going manual. I’ll pull that out and check the bore size.