Rear brake build gone sideways. 1969 FJ55 (4 Viewers)
- Thread starter Peters Moose
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- Thread starter
- #23
Thanks Scrapdadday-I might invest in an 80 series master as that seems to be a popular choice on rebuilds. (Hopefully my local toyota place has one.) Appreciate it!
Holy smokes that is a great article from what I quickly scanned so far. I think just what I have been looking for.
Much appreciated!!!!
I did not see much on the 40 series parts going into the 55's... Interesting idea though. However i really want to update to more current parts and I honestly did not think it would be such an issue. Surprising as the upgrade I did to the front axle went really well.
Captn Conch
Life Begins Above Timberline.
OK Moose, in reference to my disk conversion. I'm a half ass but do it right mechanic. After installing the disks I got tired of screwing around and took it to a shop where the pros bled it tout suite! Yes, you are chasing an air bubble or bubbles in the line. I picked it up from the shop about 45 minutes later, done deal. Maybe they blast out the bubbles under high pressure who knows?
I bought a Harbor Freight pump bleeder... no go. It doesn't matter if you have converted to rear disks or what you have now, until those brake lines are cleared of air, YOU ARE SCREWED!
No, I do not pump my brakes anymore, I don't have to jack my steering wheel to the side each time I stop, My booster is non-functional, is still on but vacuum disconnected and plugged up good so no vacuum leaks are possible. Like your '69 I now have no booster assist and it stops totally straight and without excessive pedal pressure. I do not miss the brake booster. I installed new master but could have rebuilt old one.
For the past 4+ years it is maintenance free, I love disks. IMHO the only weak link in the early FJ 55's and 40's was the damn brake cylinders. (OK, The periodic 1F Valve adjustment requirements were a PIA also.) Back plate on the old drum brakes? Mine had them they are in the box for perpetuity, no problem. If you have a solid 55 it will be worth the hassle. Rare and beautiful pigs indeed.
I bought a Harbor Freight pump bleeder... no go. It doesn't matter if you have converted to rear disks or what you have now, until those brake lines are cleared of air, YOU ARE SCREWED!
No, I do not pump my brakes anymore, I don't have to jack my steering wheel to the side each time I stop, My booster is non-functional, is still on but vacuum disconnected and plugged up good so no vacuum leaks are possible. Like your '69 I now have no booster assist and it stops totally straight and without excessive pedal pressure. I do not miss the brake booster. I installed new master but could have rebuilt old one.
For the past 4+ years it is maintenance free, I love disks. IMHO the only weak link in the early FJ 55's and 40's was the damn brake cylinders. (OK, The periodic 1F Valve adjustment requirements were a PIA also.) Back plate on the old drum brakes? Mine had them they are in the box for perpetuity, no problem. If you have a solid 55 it will be worth the hassle. Rare and beautiful pigs indeed.
The rear is just a simple 3 way T not a fancy valve.
FYI 40/45/55 axles are interchangeable. In my case I bolted in a 45 rear axle into my 40. 45 drums are more powerful so I had to compensate for them. Then when I converted to rear discs, since the 45 backing plates different, I had to do something custom... and since it was 18+ years ago.
At a level I'm somewhat surprised how much trouble you and others have had... since when I bolted on a used 80 master, I threw it on the truck without bench bleeding, poured some fluid in, and connected up the lines... I can't even remember bleeding them, much less having to do excessive amounts of bleeding. I figured I'd bleed them when I swapped in the new rear rotors and pads... but they're still sitting on the shelf in the garage.
I hope you're able to figure it out soon... I understand your frustration. As others have said, start back at square one, and go through the process step by step. It is likely something small and simple... just hard to find. When you find it, go have a well deserved cold beverage of your choice.
Random thought... If the front circuit works when the rear is capped, how is the fluid in the rear circuit compressing? Brakes work because it doesn't compress. There would have to be air in the rear circuit... or the rear circuit is bypassing. I could be wrong... but I suspect the master isn't working right and/or it has air in it.
FYI 40/45/55 axles are interchangeable. In my case I bolted in a 45 rear axle into my 40. 45 drums are more powerful so I had to compensate for them. Then when I converted to rear discs, since the 45 backing plates different, I had to do something custom... and since it was 18+ years ago.
At a level I'm somewhat surprised how much trouble you and others have had... since when I bolted on a used 80 master, I threw it on the truck without bench bleeding, poured some fluid in, and connected up the lines... I can't even remember bleeding them, much less having to do excessive amounts of bleeding. I figured I'd bleed them when I swapped in the new rear rotors and pads... but they're still sitting on the shelf in the garage.
I hope you're able to figure it out soon... I understand your frustration. As others have said, start back at square one, and go through the process step by step. It is likely something small and simple... just hard to find. When you find it, go have a well deserved cold beverage of your choice.
Random thought... If the front circuit works when the rear is capped, how is the fluid in the rear circuit compressing? Brakes work because it doesn't compress. There would have to be air in the rear circuit... or the rear circuit is bypassing. I could be wrong... but I suspect the master isn't working right and/or it has air in it.
MOTOV8R
SILVER Star
You said you have a proportioning valve, do you have a residual valve to maintain 10# of pressure on the rear brakes?
- Thread starter
- #28
Thanks Capt... and good to know I still have the option to go disc with the model year of my rig. Appreciate the detailed reply!!
Good on the 3-way piece!! I was not able to find details on it, so great to know the issue is not there. I think that the others had updated to the 80 series master like you and have had good results. That might be my next move if another few pints of fluid does not do the trick.
Nothing on a residual valve. I have not heard of that too much so will look into it. A quick scan showed only 1/8 fittings available. (I'm running 3/16 hard line with 10mm and 3/8 bubble flair fittings)
Thanks much for the info!
I had the same problem on my 74 Pig. Two issues caused it. 1) I didn't get all the air out of the new master cylinder (two reservoirs, not one), and 2) used the vacuum bleeder rather than the two person method.
Once I got my act together and asked for help with someone pushing the brake, I had it fixed in about an hour.
Once I got my act together and asked for help with someone pushing the brake, I had it fixed in about an hour.
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I'm in the process of doing it too. I did a non-ABS master with no booster, uses all new lines, all new everything.
Like you, I am chasing the rear drums and improper amount of pedal. Mine takes a full pump to make the rears work. Fronts work great.
As for front only.....I'd venture to guess 90% of disc front 40's and 60's on the road have crappy or no rear brakes. Mine don't and have not worked on my 60 for the last 5000 miles.
I'm like you, I will screw with it for just so long and I'll cap that rear end off and rock on.
Like you, I am chasing the rear drums and improper amount of pedal. Mine takes a full pump to make the rears work. Fronts work great.
As for front only.....I'd venture to guess 90% of disc front 40's and 60's on the road have crappy or no rear brakes. Mine don't and have not worked on my 60 for the last 5000 miles.
I'm like you, I will screw with it for just so long and I'll cap that rear end off and rock on.
- Thread starter
- #31
Great replys folks!! Yeah I'm going a little nutso on the rears but like lc69 I'm going to venture another time and send another few quarts of brake fluid to the recyclers. I did order a 10# residual valve for one last attempt. If not I'm going with wngrog until another solution presents itself. Txs to the res-valve, I get to make two more ends in the brake line!! Yikes.
Thanks again to all the great replys!!
Thanks again to all the great replys!!
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I'm in the process of doing it too.
As for front only.....I'd venture to guess 90% of disc front 40's and 60's on the road have crappy or no rear brakes. Mine don't and have not worked on my 60 for the last 5000 miles.
I'm like you, I will screw with it for just so long and I'll cap that rear end off and rock on.
If you block off the rear, why go thru all the trouble of setting up a dual system when you will still end up with a single brake system. that's how people die. you hit someone and they find out you blocked off 1/2 your brake system, you'll be hosed.
there are 2 things on any rig that need to function properly: steering and brakes.
rant off.
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Whatever. Rant all you want but if you tested all the disk/drum units on the road I bet 90% don't have rear brakes that do jack.
I'll get mine right. It's all new stuff.
@Peters Moose where did you get the residual valve?
I had a proportion valve built into mine and it leaked so I took it out. I might need one.
cruiserbrett
GOLD Star
1: did you bench bleed the master before installing? I found this to help immensely.
2: you can make a pressure bleeder pretty easy: The DIY $20 brake bleeder
3: Don't bother bleeding the rears until the brake shoes are adjusted properly... The way the Toyota dual piston cylinders work will allow a lot of air to be trapped and un-bleedable if the pistons are even slightly extended before shoe to drum contact. adjusting the brakes helps mitigate this problem.
4: sometimes big loops of brake tube can trap fluid with standard bleeding. pressure bleeding quickly pushes enough volume of fluid and helps prevent the bubbles from settling in the high spots in the loop.
2: you can make a pressure bleeder pretty easy: The DIY $20 brake bleeder
3: Don't bother bleeding the rears until the brake shoes are adjusted properly... The way the Toyota dual piston cylinders work will allow a lot of air to be trapped and un-bleedable if the pistons are even slightly extended before shoe to drum contact. adjusting the brakes helps mitigate this problem.
4: sometimes big loops of brake tube can trap fluid with standard bleeding. pressure bleeding quickly pushes enough volume of fluid and helps prevent the bubbles from settling in the high spots in the loop.
- Thread starter
- #35
The power bleed will be last attempt and even though I like that DIY system, I probably will still give it a go at a local brake shop and see how it goes. Yes bled on the bench and carefully installed keeping the bleed hose intact while I hooked up the system.
Thanks man fo rthe reply!!!
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MOTOV8R
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The factory master has one. You have to pull it out for rear disc conversion which is how I learned about them. If you search summit or jegs you can find several. The link I posted earlier in this thread explained why you need one. In some cases disc brakes use them as well. 10# for drum 2# for disc. The purpose of the valve is to maintain pressure in the brake line to reduce the pedal movement needed before the shoes engage the drum.
MOTOV8R
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- #39
Will add that shortly and I will post a pic as well after the long weekend.
Thanks all!
Thanks all!
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I put a non ABS 80 series master in mine and the guys I copied did not use this. In fact, I can't find anyone that has ever heard of one.
For me the purpose of keeping the drums is I had all the stuff new already on shelf and as you see from my above comments I don't think the rear brakes on these trucks do much of anything anyway.
I just ordered a proportion valve
From @Racer65 since mine was leaking and his is a pimp product.
Hipefully mine can roll without that
