brake issues on 67 fj40 (2 Viewers)

[jvincig01]

i have a 67 with disk on the front and drums on the back. i went through the brakes and put new cylinders and shoes on the back. however, i still have a problem i cannot figure out....

basically, i have to pump the brake once and the second time i can feel that they are ok and have pressure. i build pressure but am loosing it a few minutes later... this sucks.

any clue on what the issue might be? i bled the brakes and there is no air in the line.

 

[cjgoode]

what master cylinder are you using, did you bench bleed it first. Sounds like a problem with air in the system.

Also have you adjusted your rear brake shoes. You need to adjust eash adjuster out until you here the shoes rubbing on the drums then back them off just till you do not hear them. That is 2 adjusters on each wheel. If the brake shoes are not close to the drum you will have to push the brake pedal farther down or pump them.

But you might also still have air in the rear cylinders, I have read several posts here on having problems getting new cylinders properly bleed.

 

[handcannon]

It sounds like you may have two problems.

First, adjust your rear brakes like cjgoode has advised. This should take care of having to pump the brakes to get good pedal height.

Next, are you saying that you can pump up the brakes and get good pedal height. But, then while continuing to hold the pedal down to keep the brakes applied the pedal slowly continues to sink down towards the floor? If this is what you are saying then you may have a brake cylinder or caliper leaking
brake fluid, this would be very visible with fluid all over the inside of the wheel/brake parts. OR, the master cylinder is leaking fluid internally back past the piston, which does not have any visible external leaking.

A master going bad will usually start with only leaking down when mild pedal pressure is applied, but holding good with heavy pedal pressure applied. Then as it continues to wear it will start leaking down even with heavy pedal pressure applied.

IF, you are saying that you can get good pedal pressure by pumping the pedal, and that then the brakes are good as long as you hold the pedal down, you are good then. In this situation, as soon as you let up on the pedal the springs on the improperly adjusted rear shoes will pull them back in. This then pushes the cylinders back in and requires that the pedal will need to be pumped again to push the shoes back out into contact with the drum the next time they are needed.

Don

 

[mikeymouse]

Ditch the rear drums. It's a safety issue. They don't make them like that anymore. In the 60's the dual action drum brake was used on most other makes domestic and foreign. Where Toyota was during that meeting is beyond me. Most other cars on our streets can stop fast and straight, the FJ40 fall way behind in that category.

Even if you CAN get them adjusted correctly for regular use, when you need them in an emergency they will be unpredictable. I did a 270 degree spin on dry pavement because some jack-leg pulled out in front of me. I had to stab the pedal hard from 40MPH to avoid hitting him, luckily there weren't any cars near me. I almost had a heart attack. It's not a "keep it original" issue. the conversion is non destructive, and WAYYYYY more safe. I wouldn't let anyone I love drive a 40 with drum brakes.

 

[cjgoode]

Rear brake drums are not a safety issue, most braking will be by the front wheels. If you adjust them properly you probably will not have to adjust them again for years. Rear brakes to do not wear very much like the front, nor will one rear wheel not working as well as the other cause your vehicle to swerve like the front would. I seriously doubt you would even be able to tell the difference in the rear drums vs rear discs unless you are rock crawling or seriously off roading. If one rear wheel did not even work at all you probably would not even know unless you locked up all 3 tires. If you have another car and have had it for a long time you probably have changed the front disc pads many times and never the rear. My sequia rear disc pads lasted over 100,000 miles while the front probably only 20,000 miles or less. Do not let people scare you into getting rear discs. Even front drum brakes are not bad, but you I would agree you would want to check those more often far adjustment and remember to pump them and dry them a little after going through deep water.

 

[65swb45]

waiting for a follow up from the OP, especially on CJ's questions in post #2.

 

[jvincig01]

the master is the stock one that it came with in 67. I did bleed the brakes first but i agree that there is something up with the air in the system.

i did adjust the brake shoes after i replaced both the cylinders on the right rear. i didnt replace the left rear cylinders because i thought they were fine. turns out one is kind of f'ed up (doesnt leak though). basically, its harder than hell to adjust although i was able to do it. both sides in the rear have new shoes and sound like they should after you replace them.

any suggestions?

 

[jvincig01]

thanks, i have been thinking about going to rear disk but they seem so pricey. i wasnt sure how much more efficient they were for casual trail riding.

 

[jvincig01]

what master cylinder are you using, did you bench bleed it first. Sounds like a problem with air in the system.

Also have you adjusted your rear brake shoes. You need to adjust eash adjuster out until you here the shoes rubbing on the drums then back them off just till you do not hear them. That is 2 adjusters on each wheel. If the brake shoes are not close to the drum you will have to push the brake pedal farther down or pump them.

But you might also still have air in the rear cylinders, I have read several posts here on having problems getting new cylinders properly bleed.

the master is the stock one that it came with in 67. I did bleed the brakes first but i agree that there is something up with the air in the system.

i did adjust the brake shoes after i replaced both the cylinders on the right rear. i didnt replace the left rear cylinders because i thought they were fine. turns out one is kind of f'ed up (doesnt leak though). basically, its harder than **** to adjust although i was able to do it. both sides in the rear have new shoes and sound like they should after you replace them.

any suggestions?

 

[jvincig01]

Rear brake drums are not a safety issue, most braking will be by the front wheels. If you adjust them properly you probably will not have to adjust them again for years. Rear brakes to do not wear very much like the front, nor will one rear wheel not working as well as the other cause your vehicle to swerve like the front would. I seriously doubt you would even be able to tell the difference in the rear drums vs rear discs unless you are rock crawling or seriously off roading. If one rear wheel did not even work at all you probably would not even know unless you locked up all 3 tires. If you have another car and have had it for a long time you probably have changed the front disc pads many times and never the rear. My sequia rear disc pads lasted over 100,000 miles while the front probably only 20,000 miles or less. Do not let people scare you into getting rear discs. Even front drum brakes are not bad, but you I would agree you would want to check those more often far adjustment and remember to pump them and dry them a little after going through deep water.

thanks, i have been thinking about going to rear disk but they seem so pricey. i wasnt sure how much more efficient they were for casual trail riding.

 

[jvincig01]

It sounds like you may have two problems.

First, adjust your rear brakes like cjgoode has advised. This should take care of having to pump the brakes to get good pedal height.

Next, are you saying that you can pump up the brakes and get good pedal height. But, then while continuing to hold the pedal down to keep the brakes applied the pedal slowly continues to sink down towards the floor? If this is what you are saying then you may have a brake cylinder or caliper leaking
brake fluid, this would be very visible with fluid all over the inside of the wheel/brake parts. OR, the master cylinder is leaking fluid internally back past the piston, which does not have any visible external leaking.

A master going bad will usually start with only leaking down when mild pedal pressure is applied, but holding good with heavy pedal pressure applied. Then as it continues to wear it will start leaking down even with heavy pedal pressure applied.

IF, you are saying that you can get good pedal pressure by pumping the pedal, and that then the brakes are good as long as you hold the pedal down, you are good then. In this situation, as soon as you let up on the pedal the springs on the improperly adjusted rear shoes will pull them back in. This then pushes the cylinders back in and requires that the pedal will need to be pumped again to push the shoes back out into contact with the drum the next time they are needed.

Don

Thanks, Don! or should I call you the DoniLama? lame joke..ahah

I can explain in more detail but it sounds like your second scenario. There is no pedal heigh until i fully pump the brake one time. After I do that once, the second time i go to press the brake they seem fine. I can drive it for a few minutes but then the pressure is gone. If I sit on the brake, it does not lose pressure. It's only when i let off, wait a second, then I am back to giving it another pump to build pressure again. I am thinking one of my rear cylinders is bad. I checked to see if i was leaking fluid and im not... do you think it's a messed up cylinder? i replaced one side and they seem dialed in now. the other two on the left seemed ok but one is VERY hard to adjust.

 

[cjgoode]

If you have a 1967 with disc front brakes and a stock master cylinder that could be a problem. Other experts here might give a confirmation. Everything I have read says you need a master cylinder made for disc brakes and the 1967 master cylinder would be for drum brakes. It has to do with the bore and how much fluid is pushed. I think disk brakes take more fluid being pushed. Plus the 1967 stock master would be a single circuit system (1 brake line coming out) which can be a safety issue since it anything fails/leaks you loose all your brakes, but with a later dual circuit you would only loose front or rear which ever line had a failure. I am in the process of putting 1977 axles into my 1962 fj40 and I am going to use a master cylinder with brake booster from a geo metro. Several people have put them into their fj40 and fj45 based on posts I have found and said they work well. And those people have had great success without adding a proportioning valve. I have not decided if I will cut the fire wall rib and add other supports to make room for the booster, or make an adapter to move it past the rib on the firewall. I had also made a post about is a brake booster required for adding front disc brakes to the older fj40's and the consensus was no you do not need a brake booster although highly recommended with discs, but you did need a dual circuit master made for discs.

Here are some threads you might want to review
This fj45 thread has good info on using the geo metro setup
https://forum.ih8mud.com/fj45-owner...nd-restoration-info-thread-7.html#post3988272


https://forum.ih8mud.com/40-55-series-tech/464213-my-single-circuit-brake-upgrade.html

https://forum.ih8mud.com/40-55-series-tech/449791-disc-brake-conversion-booster-required.html

https://forum.ih8mud.com/fj25-owners-group/426386-brake-booster.html

 

[jvincig01]

If you have a 1967 with disc front brakes and a stock master cylinder that could be a problem. Other experts here might give a confirmation. Everything I have read says you need a master cylinder made for disc brakes and the 1967 master cylinder would be for drum brakes. It has to do with the bore and how much fluid is pushed. I think disk brakes take more fluid being pushed. Plus the 1967 stock master would be a single circuit system (1 brake line coming out) which can be a safety issue since it anything fails/leaks you loose all your brakes, but with a later dual circuit you would only loose front or rear which ever line had a failure. I am in the process of putting 1977 axles into my 1962 fj40 and I am going to use a master cylinder with brake booster from a geo metro. Several people have put them into their fj40 and fj45 based on posts I have found and said they work well. And those people have had great success without adding a proportioning valve. I have not decided if I will cut the fire wall rib and add other supports to make room for the booster, or make an adapter to move it past the rib on the firewall. I had also made a post about is a brake booster required for adding front disc brakes to the older fj40's and the consensus was no you do not need a brake booster although highly recommended with discs, but you did need a dual circuit master made for discs.

Here are some threads you might want to review
This fj45 thread has good info on using the geo metro setup
https://forum.ih8mud.com/fj45-owner...nd-restoration-info-thread-7.html#post3988272


https://forum.ih8mud.com/40-55-series-tech/464213-my-single-circuit-brake-upgrade.html

https://forum.ih8mud.com/40-55-series-tech/449791-disc-brake-conversion-booster-required.html

https://forum.ih8mud.com/fj25-owners-group/426386-brake-booster.html

CJ, this is really helpful. I really appreciate this. I am going to start by inspecting the lines to see how it's setup. Pretty sure I only have 1 master cylinder though

 

[cjgoode]

You would only have 1 master, but 1 line coming out of it like this

This is a single circuit used in the 1960's. Only 1 brake line feeding both the front and rear brakes.

 

[jvincig01]

You would only have 1 master, but 1 line coming out of it like this

This is a single circuit used in the 1960's. Only 1 brake line feeding both the front and rear brakes.

Let me see if I have a picture of this. I am pretty sure I have one on my home computer.

JV

 

[handcannon]

Thanks, Don! or should I call you the DoniLama? lame joke..ahah

I can explain in more detail but it sounds like your second scenario. There is no pedal heigh until i fully pump the brake one time. After I do that once, the second time i go to press the brake they seem fine. I can drive it for a few minutes but then the pressure is gone. If I sit on the brake, it does not lose pressure. It's only when i let off, wait a second, then I am back to giving it another pump to build pressure again. I am thinking one of my rear cylinders is bad. I checked to see if i was leaking fluid and im not... do you think it's a messed up cylinder? i replaced one side and they seem dialed in now. the other two on the left seemed ok but one is VERY hard to adjust.

You're the first person to put me in that lofty of a position out side of my wife. She does give me burnt offerings at times. I guess I do that to myself sometimes also since I go by the rule of " If it's smoking it's cooking and if it's black it's done".

Your description is exactly what I was describing in my second scenario. Your brake shoes are far enough away from the drums that it takes the first pump to move them close to the drum surface. The second pump then puts the shoe in contact with the drum. As soon as you let up on the pedal the shoe return springs start doing their job of pulling the shoes back to their resting position. The next time you press the pedal the process of moving the shoes out starts from the beginning again.

The shoes need to be adjusted out some more so they are all but touching the drum. Now with a cylinder that has the adjuster so stiff it is hard to turn, that cylinder will be very difficult to adjust properly.

What you need to do is take that drum back off. Then remove enough of the shoes, springs etc until you can get to the adjuster. Use some slip-joint pliers and completely thread the adjuster out. Then wire brush and generally clean the threads and lightly grease them. The adjuster must be cleaned to the point that you can turn it by hand. If you are unable to get it to turn freely then it needs to be replaced. Whenever I replace shoes I always make sure the adjusters are free enough to turn by hand, whether new or re-used.

This is something I learned from the school of hard knocks. I've been where you are now and I hate having to take things apart to re-do them.

Don

 

[jvincig01]

Let me see if I have a picture of this. I am pretty sure I have one on my home computer.

JV

Looks like I have the same setup. My front disks are off a toyoya mini truck (dont know the year) and it looks like I have the same setup as you. If I replace the master, do you have a recommendation? Something that can support front disk and rear drum? I included more pictures below.

 

[jvincig01]

You're the first person to put me in that lofty of a position out side of my wife. She does give me burnt offerings at times. I guess I do that to myself sometimes also since I go by the rule of " If it's smoking it's cooking and if it's black it's done".

Your description is exactly what I was describing in my second scenario. Your brake shoes are far enough away from the drums that it takes the first pump to move them close to the drum surface. The second pump then puts the shoe in contact with the drum. As soon as you let up on the pedal the shoe return springs start doing their job of pulling the shoes back to their resting position. The next time you press the pedal the process of moving the shoes out starts from the beginning again.

The shoes need to be adjusted out some more so they are all but touching the drum. Now with a cylinder that has the adjuster so stiff it is hard to turn, that cylinder will be very difficult to adjust properly.

What you need to do is take that drum back off. Then remove enough of the shoes, springs etc until you can get to the adjuster. Use some slip-joint pliers and completely thread the adjuster out. Then wire brush and generally clean the threads and lightly grease them. The adjuster must be cleaned to the point that you can turn it by hand. If you are unable to get it to turn freely then it needs to be replaced. Whenever I replace shoes I always make sure the adjusters are free enough to turn by hand, whether new or re-used.

This is something I learned from the school of hard knocks. I've been where you are now and I hate having to take things apart to re-do them.

Don

haha, my wife gives me burnt offerings all the time. she cant cook for anything...kidding, kind of.


Here is a picture of the rear drums, you can see the right side completed has new cylinders and the left doesnt... old picture taken before i put the new shoes on and tested it out. They sound like they should once i put the drum back on and spin them by hand but i am wondering if the old cylinder is just F'ed up? I feel like it's a combination of the master cylinder not being strong enough to distribute pressure to front disk and rear drums and bad rear cylinders on the left.

i have also included a picture of the front brake setup. if you know what year mini truck this is off of, let me know what you think. let me know what kind of master i should replace my old one out with. thanks!

 

[cjgoode]

I am putting in a brake master and booster from a late 80's geo metro. Picked it up off ebay for like $30. They are plentiful.

Scroll down on this link, they put one in this fj45 with an adapter to make the booster stick out beyond the rib on the firewall.
https://forum.ih8mud.com/fj45-owner...nd-restoration-info-thread-7.html#post3988272

This post goes over some options as well. The thing is you need a master and recommended booster that will fit and not hit the carburetor.

https://forum.ih8mud.com/fj25-owners-group/426386-brake-booster.html

Look at those posts, but I do believe the root of your problem is that master cylinder assuming your rear brake shoes are adjusted properly. You could start a new post asking about master cylinder options with front disks, and also ask if the old single circuit master will work. I have never seen a post on here where someone did a disk conversion and kept the singe circuit master from the 1960's. I got my front disc axle installed last night and plan to start working on installing my geo master brake setup next week.

 

[albee]

I just did a rear disk swap on my 67 this week. If you want any of the old wheel cylinders, you can have them for the price of shipping. I honed them out and put new cups in them a couple of years ago. With Steve's (poser) brackets and rotors I have about $300 in the rear disk conversion.

I just got tired of adjusting them twice a year. It was a pain to get all of the air out of the wheel cylinders. I ended up opening the top of each wheel cylinder and tiping the cup to get the air out. I know lots of people will say you do not need to do that, all you need to do is adjust and bleed. I adjusted the the brakes and bleed over and over and still had to pump the brakes. Then after I followed the advice of Mark (65swb45) and tipped the cups I had solid brakes w/o pumping.
Good luck and P.M. me if you want those cylinders before I scrap them.
Albee