more break power on a PZJ75 (1 Viewer)

[GooSe77]

Diggin this back out .....
I now have the 80 series brake booster running for 2 years now - way better braking performance. Lifted the linkage for the rear valve about 4cm. I still can't get the rear wheels to block when hitting the brake. Ok, I do have 2100 Kilos on that axle .... Do you guys thing switching to a smaller brake cylinder will help ?

 

[clintnz]

Are you sure the rear LSP Valve is working properly? I replaced mine with a manual Wilwood valve, once it was tuned to suit the vehicle it was definitely an improvement. I'd try that before changing master cylinder size. With that sort of weight on the axle it could be that you need bigger brakes. I've got the big later model 80 series discs in the back & they are great, can't pack 2 ton in the back of my SWB but I do tow a heavy trailer sometimes & give them a workout.

Should also drop these pics here of the 80 series booster & the longer clevis needed to link it up to the 70 series. Bolt in otherwise.

Cheers
Clint

 

[jblueridge]

You lifted the linkage at the end of the arm for LSPV.
I just found that the lspv itself can be moved up or down.
I pulled my lspv down a bit and suddenly got great brakes.

I read somewhere on here that the lspv can get dirty and need a clean.

 

[Tinman]

bastian .... check if your brake proportion valve is adjustet correctly, my bj75 was suddenly braking extremely well, just because some leaf in the rear springs had broken, causing the rear end of the car to lower for perhaps 2-3 cm ..... then the car thought i had 300kg of extra load in the back, but after replacing the rear springs with brand new ones.

Making a comment here because I had trouble with this on my HZJ75 ute for a long time. I would adjust the proportion valve and it would come good and a week later the brakes were crap again. I still have the original springs but the have been retempered and reset slightly higher. My spring hangers are about 1” longer than OME. So just under 2” of lift. I eventually put a taller bracket on the axle attachment point for the proportioning valve rod. Now attaches 2” higher. Works much better

 

[SNLC]

The brakes on the gold PZJ70 are some of the best brakes I have ever experienced.

Lots of people say run the 80 MC but it is designed for disc/disc and honestly I am not disputing it is good, I have not ran it on a disc/drum truck.

I am running 80 calipers, rotors and pads up front. New drums and shoes in back adjusted near perfect. I removed the LSPV and installed a proportioning valve. New 70 booster and MC as well and all new lines.

The truck stops incredible.

Cheers

 

[umpqua]

Thanks for reviving this. It's on my list of to do's.

 

[GooSe77]

I am running 80 calipers, rotors and pads up front.

And this on a PZJ70 ? Do you have some pictures of this ?

 

[SNLC]

And this on a PZJ70 ? Do you have some pictures of this ?

Yup in the build thread.

It’s not a bolt on job.

Cheers

 

[jblueridge]

Early FJ80's had rear drums in back.
That's the dual-diaphragm booster and MC I went with for my BJ74.
Vast improvement.

 

[roscoFJ73]

Early FJ80's had rear drums in back.

I think there were some 80s with drums all round. Low spec models with 15 inch wheels sold in developing countries for qangos, govt, companies ect.

 

[SNLC]

I think there were some 80s with drums all round. Low spec models with 15 inch wheels sold in developing countries for qangos, govt, companies ect.

Not from what I have seen, they just have smaller rear discs.

The statement about FJ80’s is correct, drums in the rear till the end of 92.

Cheers

 

[JuanJ]

I think there were some 80s with drums all round. Low spec models with 15 inch wheels sold in developing countries for qangos, govt, companies ect.

Hello,

That and a carbureted 1FZ engine for low octane fuel. And 2/3 barn doors, usually with provision for a spare tire carrier.





Juan

 

[GooSe77]

Yup in the build thread.

It’s not a bolt on job.

Cheers

Do you have a link fpr me ?

 

[SNLC]

Do you have a link fpr me ?

Sure, front axle mods start about here....

Builds - PZJ70 build-refurbish!?

Why not reman the cross member? I’ve always looked it that piece and wondered if it can be made better. If it causes interference why not reconstruct it?

forum.ih8mud.com

Cheers

 

[GooSe77]

THX

 

[dcruiser666]

I pulled a booster off a diesel townace truck (I think it was a '96 or '97) to replace mine when it went. I didn't research if it was better but it was a direct bolt in with no modifications. Braking was definitely stronger than before when the og booster wasn't leaking, but this doesn't necessarily mean it's an upgrade. So, it's compatible, maybe you can find out if it's better.

 

[Honger]

Early FJ80's had rear drums in back.
That's the dual-diaphragm booster and MC I went with for my BJ74.
Vast improvement.

Did you need a spacer for the 80-series booster to mount to the 74's firewall? Or direct fit? I'm assuming you had to extend the linkage as mentioned earlier in the thread...

 

[Hulsty]

Few years on my are still working excellently, especially with QFM A1RM pads.

 

[jblueridge]

It was a direct fit but I did need an extended linkage to connect to pedal.
80 series Master had different orientation of brake lines. Made some to suit.