Need Stronger Brakes (1 Viewer)

[Glenn-BJ74]

My front brakes are in good condition (17k since last rebuild) and my rears are due for replacement in 5k this fall. I clean them regularly.
What are my options to upgrade brakes on a BJ7? Is there a rear disc set-up that would help me. Can I put on a stronger brake booster?
Others that have 74's similarly comment about the weak stock brakes, especially with larger tires.

This is a both a safety and performance upgrade, which I need to look into before I rebuild my rears.

Thanks in advance.

 

[lshobie]

Hmm, is your brake valve proporting thingy set up right?? If you lifted it and it wasn't adjusted that would affect the breaking of the rear - like they wouldnt be working hard at all. If set up properly they should work just fine.

I have a set of drums here if you need some, freshly turned, lots of life of a JDM BJ74, was my spare set for when a new vehicle would come in.

 

[crushers]

agreed, the load sensor must be adjusted after a lift...

if you are going to disc then get the proper FF disc axle from a 75 sereis or contact Dave at Japan 4X4

 

[Rigpig]

4runner calipers and 1"bore brake master cylinder should help alot. Beats spending a bunch of money on another full floater.
Cheers!

 

[Radd Cruisers]

4runner calipers and 1"bore brake master cylinder should help alot. Beats spending a bunch of money on another full floater.
Cheers!

This is a hit and miss conversion. It does not make that much of a difference if the brakes were working well in the first place.

The brake systems on some of these trucks just don't make sense to me. I have been through numerous systems looking for the extra stopping power that should be there and have not had the kind of success that the time and parts I have changed should dictate.

For example, the brakes on my 1981 BJ42 are excellent. Strong, with no noticeable fade at any speed. My HJ61 brakes are soft and not very aggressive - and I have been through the system several times - literally replacing almost every part in the effort to get crisp and powerful brakes with no substantial gain in power.

The brakes on any Land Cruiser -should- be plenty strong enough for tires up to and exceeding 36", the reality is that they are not always up to the task.

I think the key is to use really high quality parts: the best pads, rotors, shoes etc... that you can get. Shoes are totally fine in the rear and are only a drawback if you're doing lots of running through water. I don't think the rear discs are that much of an improvement overall if you're drums are working well - rear brakes do the minor share of the braking of any system.

Discs become a favorable swap if you're in the water a lot, or are running much bigger tires (I don't consider 33s to be all that big). They do offer a more progressive feel over drums to some degree.

Locally, Brembo front rotors are pretty much the best thing going. I don't give too much credence to slotting or cross-drilling - trap dirt, rapid wear. A high quality set of metallic pads is what I recommend to most clients. Rotors and pads need to be bedded in properly for best performance.

hth,

John

 

[crushers]

proper adjustment
good parts
get rid of the rear weight valve

and life is good...

 

[Radd Cruisers]

proper adjustment
good parts
get rid of the rear weight valve

and life is good...

Agreed.

Proper adjustment of the rear brakes is essential. Most people do not do it properly - the factory manual is a good place to start.

If the LSPV is working as it should, and is adjusted properly, there's no need to replace it. Often they are corroded, full of dirt in the mechanism, or not adjusted properly...


~John

 

[roscoFJ73]

Ive got a drum brake model and a factory rear disc model and I dont think the disc conversion is worth.
it.
The only real advantage disc have over drum is the disc cools quicker and suffers less fade.
Stopping power under normal conditions is about the same.

The disc has also has other advantages and disadvantages.
Its easier to work on and has less parts.
However the drum parts are cheaper and getting the handbrake to work on a disc model is a PITA

 

[Glenn-BJ74]

Load Sensing Proportioning Valve Adjustment

OK then rear drums should do the job. Since my rear brakes have been adjusted, I guess my Load Sensing Proportioning Valve (LSPV) is out of adjustment, due the OME springs.


Have you guys ever looked in the manual (page BR-54) on how to do this ?? The procedure not practical for the average guy to do, since it involves putting max weight in the back ( rear axle weight at 2,469 lbs) measuring axles weight and measuring front and back brake fluid pressures, etc. etc.

I assume since my truck has OME springs it sits, what 3" higher than stock - telling the LSPV their is less load in the back and putting less braking there. Is that the way its suppose to work ?

So my plan is to increase the adjustment (move spring up toward
the LSPV), I guess by the amount of the effective of the lift, whatever that is.

What about removing the bloody thing - would that give me maximum back braking or would that cause other problems.

 

[crushers]

if you want to remove it then you need to run a line from the front... well at least i had to...
my braking on the PZJ70 was excellent after i got rid of that chunck of metal...

since you went up 2 1/2" all you really need to do is either drop the frame end of the arm 2 1/2" or rebend the spring rod 2 1/2"... your weight has not changed it is just the distance between the valve and the frame that changed. the valve "thinks" the back of the truck is lighter than it really is...

i hope this makes some sort of sense to you...

 

[oldblue]

Is it not easier to just lengthen the conecting linkage that fits between the spring and the diff houseing by 2.1/2"

 

[crushers]

it won't be a full 2 1/2" since you are going on an angle but yes, lengthening the rod should work...

 

[lshobie]

If you want really good brakes put the newer HZJ79 series axles on. The brakes on these use the new tundra caliper and a huge rotor on the front - and huge drums on the rear. I never have braking problems when I am wheeling - not like on th eolder uits when they have just about faded to nothing after a day of mud and water wheeling.

The only problem with the new axles is the 5 lug pattern - not fun getting rims - but I may have figured it out.

 

[Glenn-BJ74]

got stronger brakes

[FONT=Arial, Helvetica, sans-serif]I assume the LSPV uses the spring rod to determine ride height and payload and regulates rear braking pressure to give [/FONT]maximum stopping power without causing the rear tires to lose traction. I guess the idea is to prevent rear brake lock-up, with a lightly loaded truck, which can be a hazard in slippery conditions while braking in a corner. After a 3" lift , the LSPV is no longer delivering the proper line pressure to the rear brakes.

Well I lengthen the LSPV adjustment to the maximum (the extent of adjustment is 93mm eye to eye between the shackles) on the rear axle, which raises the spring rod (like pushing the rear axle up). Then I lowered the LSPV itself (two 12mm nuts allow some downward adjustment) - same effect - reducing distance between the frame and rear axle). See BJ74 Repair Manual pps BR54 step #5 and #6). Now the spring rod (from the frame mounted LSPV) is much higher now - like a loaded truck situation - hopefully giving me more rear brake pressure.

I just road tested the truck and there is considerable improvement in braking. The issue now is that I may have too much rear braking pressure, but if that is a problem I will lower the spring rod.

Thanks for everyone's input. I will pass this info on other BJ74 owners.

 

[Malahki]

Just wondering how the LSPV adjustment turned out? Didnt know what was causing my poor braking ability, I am sure that this is part of my problem. Shouldn't I be able to lock up my front and rear wheels on dry pavement? I cant lock anything up right now (33's on a BJ71 and 35's on a BJ74)

 

[roscoFJ73]

I cant lock anything up right now (33's on a BJ71 and 35's on a BJ74)

I would be surprised if it would lock up with those size tyres.
Replacing the rubber hydraulic lines can help

 

[crushers]

with?

<and PLEASE don't say SS>

 

[roscoFJ73]

with?

<and PLEASE don't say SS>

with new

 

[crushers]

makes sense...

 

[jake2far]

My front brakes are in good condition (17k since last rebuild) and my rears are due for replacement in 5k this fall. I clean them regularly.
What are my options to upgrade brakes on a BJ7? Is there a rear disc set-up that would help me. Can I put on a stronger brake booster?
Others that have 74's similarly comment about the weak stock brakes, especially with larger tires.

This is a both a safety and performance upgrade, which I need to look into before I rebuild my rears.

Thanks in advance.

I own 1985 BJ70, installed Emu spring kit, rear disc brakes, new master cyl for the rear disc conversion, great pedal nice and firm but took alot of foot pressure from the larger diameter master cyl for the rear disc calipers. I found a 1996 dual diaphram booster from a Toyota T100 fits without alot of work, needs a longer yoke on rod end and center hole through fire wall opened up (die grinder and 5 min). The dual diaphram set up solved the problem for me. Bought the Booster from wrecking yard for $75.00. Really a good fix if all else is in good shape.

Jim