Master Cylinder and Brake “Upgrade” Questions

[poptart]

So, the brakes on my FJ62 have never been “Good”. They’re not bad as long as you drive a little defensively. However, my wife’s car was just wrecked (waiting on the insurance to say if it’s totaled or not) and while we currently have a rental. I’m not sure how long we’ll have that and there’s a possibility she might have to daily the cruiser. So I need the brakes as good as possible for her. I rebuilt everything in 2020 so, here’s mine current set up:
‘94 V6 4Runner Front Calipers (Centrics)
‘95 V6 4Runner 9.5” Brake Booster (Cardone)
‘93 V6 T100 Master Cylinder (Advics BMT-051)
Braided Stainless Brake Lines
Everything else is new, rotors, drums, pads, shoes, hardware and wheel cylinders.

I after I installed the OME 2.5” I raise the LSPV arm off the axle and I guess I was raised it a bit to much and was locking up the rears first. But I have since cut down my raised mount for that and solved that issue.

So the issue I have now is, the brakes still suck. Pedal feels is ehh. Brakes will pull to one side, then I’ll bleed them and they’ll pull to the other side. I’ve bleed them traditionally with a helper, bleed them with a hose into a bottle, bleed them with a Mityvac vacuum bleeder. Thought maybe air was getting past the threads, so I’ve wrapped them in Teflon tape and slap a bunch of grease around them. Still can not get them balanced and feeling decent.

Bleeding order was always done in the order dictated in the manual and the LSPV done last.

Couple of thoughts going through my mind on this. Not on why it’s not balanced, but why they’re just poopy in general.

One, the bore on the master is to large. However, I pretty sure it’s a 1” bore, maybe, and I think that’s matched to the 4Runner calipers I have. Well aware that larger bore, equal stiffer pedal with less pressure, but the volume still needs matched to calipers. And the 1” master was used with those calipers, pretty sure… also looking at trying a Supra 15/16” bore master and see if that’s any better.

Second, I’m going to order speed bleeders (P/N SB1010-SS) and try those.

Overall just looking for ideas and thoughts on any thing I could be missing or over looking.

 

[poptart]

Pretty much edited and changed the original post so, bump

 

[georgebj60]

I can’t help, but will be following as my brakes are mostly new too, and not awesome. I guess the ultimate test is to see, in a controlled situation, if the wheels can be locked up. Beyond that, even if the pedal doesn’t feel like a modern car you’re not going to get any better braking than that. The rest is probably learning the pedal feel.
That said, mine don’t pull left or right. That sounds like a caliper or wheel cylinder problem. I think air in the system would just result in a spongy pedal. But I’m no expert.

 

[poptart]

I can get the driver side front the lock up currently. But only the drivers side pulling the cruiser into the on coming land. Making it a little spicy when braking hard.

 

[OSS]

You’re not going to like what I’m about to say but here it is:

The stock FJ62 (and FJ60) tires were 225/75R15. That’s a 28 inch diameter tire. These trucks stop great with those dinky tires and stock brakes because the leverage on the smaller tire is so much less than typical off-road tires (31” and taller),

If you’ve got bigger tires on your cruiser — that’s why it doesn’t stop so great with the braking components.
If you want it to stop safely with your wife driving it (good idea). Get a 2nd set of wheels with stock tires on it.

 

[cps432]

Are you bleeding the rear driver side first? I know you said you’re going according to the prescribed procedure, but on these trucks the furthest point from the master is the rear driver side. I have basically the same setup in my 60 and I have never been able to lock up the brakes unless I throw the transmission in neutral, but then I lose control and it gets a bit squirrelly. Short of doing some major modifications and installing tundra rotors and calipers all around I don’t think you’ll get them to function like a new vehicle.

 

[georgebj60]

What sort of modifications would be involved? What would it take to get these things to stop like a new car, less the ABS of course?

 

[cps432]

What sort of modifications would be involved? What would it take to get these things to stop like a new car, less the ABS of course?

I believe you can install tundra brakes on them. I’ve seen some threads on it in the past. Lots of work though.

 

[Spook50]

Are you bleeding the rear driver side first? I know you said you’re going according to the prescribed procedure, but on these trucks the furthest point from the master is the rear driver side. I have basically the same setup in my 60 and I have never been able to lock up the brakes unless I throw the transmission in neutral, but then I lose control and it gets a bit squirrelly. Short of doing some major modifications and installing tundra rotors and calipers all around I don’t think you’ll get them to function like a new vehicle.

Called it on the bleed order. Driver rear, passenger rear, passenger front, driver front, LSPV (if you have one). Took me a while to realize that but once I did my brakes worked right!

Edit: Corrected myself. Got dyslexic for a minute.

 

[poptart]

Are you bleeding the rear driver side first? I know you said you’re going according to the prescribed procedure, but on these trucks the furthest point from the master is the rear driver side. I have basically the same setup in my 60 and I have never been able to lock up the brakes unless I throw the transmission in neutral, but then I lose control and it gets a bit squirrelly. Short of doing some major modifications and installing tundra rotors and calipers all around I don’t think you’ll get them to function like a new vehicle.

Yepp,
Driver Rear
Passenger Rear
Driver Front
Passenger Front
Then LSPV

I can get the drivers front to lock up, but the passenger front won’t. When my LSPV arm was higher, causing more pressure to the rear I could get the rears to lock up no issue.

I should note that before I tried bleeding with the vacuum bleeder, I never locked them up or tried, but the brakes pulled to the passenger side.

And for what it’s worth, I know they’ll never be great brakes, but I’ve had and driven plenty of old cars from things with no vacuum booster and drums all the way around, to similar set ups as the 60 series. I’ve never had issues like this before. Am not saying it’s nothing I can’t live with, but it’s something I’d rather not have to wife constantly fighting. She drives the 62 as much as I do and knows the problems and concerns with it, but if it’s going to be DD’d in traffic I’d like to get it as sorted out as possible.

Just ordered more brake fluid and the speed bleeders, so hopefully those come in before we have to turn in the rental.

 

[Effjaysixtwo]

Have you checked the metal brake lines for pinches? Happened to mine, on the driver side. Replacing the metal line, no more pulling and the pedal feel improved too.

 

[cps432]

Yepp,
Driver Rear
Passenger Rear
Driver Front
Passenger Front
Then LSPV

I can get the drivers front to lock up, but the passenger front won’t. When my LSPV arm was higher, causing more pressure to the rear I could get the rears to lock up no issue.

I should note that before I tried bleeding with the vacuum bleeder, I never locked them up or tried, but the brakes pulled to the passenger side.

And for what it’s worth, I know they’ll never be great brakes, but I’ve had and driven plenty of old cars from things with no vacuum booster and drums all the way around, to similar set ups as the 60 series. I’ve never had issues like this before. Am not saying it’s nothing I can’t live with, but it’s something I’d rather not have to wife constantly fighting. She drives the 62 as much as I do and knows the problems and concerns with it, but if it’s going to be DD’d in traffic I’d like to get it as sorted out as possible.

Just ordered more brake fluid and the speed bleeders, so hopefully those come in before we have to turn in the rental.

It should be:
DR
PR
PF
DF

And you’re certain you bench bleed the MC and there’s no air trapped in there?

 

[Spook50]

It should be:
DR
PR
PF
DF

And you’re certain you bench bleed the MC and there’s no air trapped in there?

THIS! I corrected my previous comment.

 

[poptart]

It should be:
DR
PR
PF
DF

And you’re certain you bench bleed the MC and there’s no air trapped in there?

Shouldn’t the drivers front be done before the passenger front. Your going in order of longest hydraulic line. The drivers front is a longer run than the passenger front since the soft line to the axle is further to the passengers side.

MC was bench bleed.

Have you checked the metal brake lines for pinches? Happened to mine, on the driver side. Replacing the metal line, no more pulling and the pedal feel improved too.

I have given them a good look over and haven’t noticed anything.

 

[Cruzerman]

Were they better at one time? Perhaps you expect too much? Can you lock them up? On my 60, I had put in the 4runner front calipers. Didn't change anything else. I was satisfied with the results. But this is not going to stop like a car.

 

[cps432]

Shouldn’t the drivers front be done before the passenger front. Your going in order of longest hydraulic line. The drivers front is a longer run than the passenger front since the soft line to the axle is further to the passengers side.

MC was bench bleed.



I have given them a good look over and haven’t noticed anything.

Follow your lines. I have a 60 and I know the 62 is slightly different, but I believe the basic routing is the same. The MC goes to the driver front then to the passenger front then to the passenger rear then to the driver rear. You wanna bleed it backwards.

At least that’s what I remember from two years ago when I rebuilt my brake system. I could be wrong and often am. And it’s been a long long day trying to pull a pitman arm off my gear box...

 

[poptart]

Follow your lines. I have a 60 and I know the 62 is slightly different, but I believe the basic routing is the same. The MC goes to the driver front then to the passenger front then to the passenger rear then to the driver rear. You wanna bleed it backwards.

At least that’s what I remember from two years ago when I rebuilt my brake system. I could be wrong and often am. And it’s been a long long day trying to pull a pitman arm off my gear box...

FJ60 and FJ62 are pretty much the same. The FJ62 just has the addition of the LSPV.

Both the front and rear axles have T’s mounted on the passenger side of the diffs for the brakes.

 

[poptart]

View from behind the passenger front wheel

 

[bottombracket]

I’ll be honest, 4 years ago I did 4 runner calipers and 80 non ABS master on my 1989 HJ61 (brake system same as US FJ62). The brakes were ok to good, but not exceptional. I comprehensively redid the brakes and knuckles with OEM parts, and I even replaced the hard lines across the axles with brand new ones from @Rainman. It was pretty underwhelming…braking was ok, and like you I could never get it dialed IN in.

About six months ago I completely redid the brakes on my 1990 FJ62, with a City Racer brake booster, and OEM everything else including hardlines by Rainman, and the OEM Japanese loaded calipers from Cruiser Outfitters. I replaced everything except the rear drums and shoes as they were in great shape.

It was a revelation. It was the best braking 60 series cruiser I have driven. So much so that I am now redoing the HJ61 in the same way, ditching the 80/4runner combo to go back to stock.

 

[Lead Head]

I just finally got the brake system on my FJ62 redone, and it extremely pleased with it. The pedal is very firm and grabs right at the top. Braking performance seems completely satisfactory. Rebuilt OEM calipers, all new shoes/cylinders/drums in the rear, rebuilt AISIN master cylinder. The only original parts are the booster, and the LSPV. Also, contrary to popular belief, the LSPV are actually serviceable. I disassembled mine and it was packed with garbage (thankfully no rust). I completely cleaned every bore and orifice out, removed all the build-up and accumulated junk, and put it back together.

Here's how I bled it:
- Master (with the little loop hose kit the master came with, that allows you to pump the fluid right back into the reservoir. Make sure the lines stay submerged!
- LSPV
- Passenger Rear
- Driver's Rear
- LSPV (yes, bled the LSPV twice)
- Passenger Front
- Driver's Front

Couple of things:

1) I've found that my FJ62 is VERY sensitive to the rear drum adjustment. If it's not dead on, you will have excessive pedal travel. If you put your foot on the brake pedal and move the parking brake - you can actually feel the two interacting. It indicates to me that getting the adjustment right is critical

2) By Newton's third law, even if you have air in one side of the system, both sides should still have equal braking pressure. Trapped air in the lines just results in excessive pedal travel and low feedback. But the braking force should still be equal side to side. That's because the air bubble will push just as hard against the fluid on the other side of the bubble. So if one side is locking up, but not the other, this is suggestive of a mechanical problem. Either the caliper is not functioning correctly, or the pads/rotors have an issue, the soft lines are failing or there is a blockage somewhere.

...and finally, when you look at contemporary reviews of the FJ62 when it came out - it was actually praised for its braking performance. Motorweek clocked 130 feet 60-0 with "Good pedal feel and feedback". That is actually still competitive with many modern trucks. I think most of the braking performance issues with these trucks comes from degraded components rather than inherent design issues.