Brakes in my bj

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B

BJ73QLD

10 Year
Joined
Feb 19, 2014
Threads
3
Messages
14
G'day all.


I have recently Brought at 86 BJ73 mwb, brakes weren't very good, only the front left would lock up if I stood on it, changed all dirty fluid out, and bled, looked to get a lot of air out, still had a spongy pedal with the same problem, so I bled the portion valve, stil had dirty fluid ? ? but same result, pedal is now hard but brakes still don't work & I get the brake light coming up after pumping the pedal, but the fluid does not drop.?!?!?!




any ideas, cheers
 
BJ73QLD said:
G'day all.

I have recently Brought at 86 BJ73 mwb, brakes weren't very good, only the front left would lock up if I stood on it, changed all dirty fluid out, and bled, looked to get a lot of air out, still had a spongy pedal with the same problem, so I bled the portion valve, stil had dirty fluid ? ? but same result, pedal is now hard but brakes still don't work & I get the brake light coming up after pumping the pedal, but the fluid does not drop.?!?!?!

any ideas, cheers
Click to expand...

Sorry to hijack your post mate, I saw your from QLD, assuming. Can you tell me if this is an Australian forum or is it American as well, I'm new the site? Cheers
 
BigBlurter said:
Sorry to hijack your post mate, I saw your from QLD, assuming. Can you tell me if this is an Australian forum or is it American as well, I'm new the site? Cheers
Click to expand...

American mostly I think, but has members from all over the world
 
IMO the brakes on those things are a bit under engineered for the size/weight of the trucks


might be worth pulling the front callipers down to check for seized pistons that's a pretty common problem, you can usually see uneven pad wear if there are seized pistons, also same for the rear pull the drums off and check the condition of the drums and shoes and adjust them up accordingly. I had problems with my FJ75 when I put 35" tyres on it even after I had all the brakes overhauled (new calliper kits, pads, rear shoes, skimmed rotors etc) it still wouldn't stop very well, I converted it to rear disc and put a second booster (remote PBR VH40) on the front brake circuit and now the thing stops like my VY Commodore it was a 1000% improvement
 
@ big bluter- yeah nth west qld. See heaps of ozzies on here so yeah don't see any dramas.

Yeah I see. I I know the front right pads are right down.
But I jacked the rear up, took a drum off, rear pads are alright, pumped the brakes while the drum was off, noticed the wheel cyl didn't do a thing, not sure if that valve thingo was open or not because of how I had the car jacked..... How do you bleed the master cyl on the older 70's?

I had been sitting for a few years..

:-)
 
BJ73QLD said:
I jacked the rear up, took a drum off, rear pads are alright, pumped the brakes while the drum was off, noticed the wheel cyl didn't do a thing, not sure if that valve thingo was open or not because of how I had the car jacked.....


I had been sitting for a few years..
Click to expand...


quite likely you've got seized pistons if its all being sitting for a while and nothings moving, time for a stripdown of the wheel cylinders and callipers


another common upgrade once you've got the brakes working properly is an 80 series dual diaphragm booster there should be plenty of info about it on here
 
Yeah for sure. Is there much you can do as far as the wheel cyl goes?? Or just put new ones in!?! I think the master is alright seeing I can get one wheel to lock up? Agree?

I hate brakes
 
I go through the same process every time a friend or I buy an old landcruiser;
New wheel cylinders
New drums
New shoes
New pads
New rotors (while I'm there, I normally fit new wheel studs and nuts on the front at least)
Rebuild front calipers (average 3 out of 4 pistons seized)
Stainless Sleeve and rebuild master cylinder (because BJ74 masters have different outlet positions to normal J7x landcruisers to keep the lines away from the turbo.

If you're not willing to start by replacing everything, tell us more about the brakes, how high is the pedal? how many pumps of the pedal to get the light on?

I've ordered lots of bits out of online autoparts at geebung in brisbane via their ebay store and their service has been great, on more than one occasion they've had stuff arrive at my work (capalaba) the same day that I ordered it.

Peel back the seal on wheel cylinders, if there is fluid past the seal (pretty good odds) then they're stuffed, and at the price it isn't worth re-kitting them, just replace them.
 
HEY mate. I took the left drum off this arvo, all rusty, full of dirt etc, no recent ware marks on the pads if you know what I mean, only light ones from the hand brake. popped the shoes off, still plenty on them, 5mm or from steel, that still alright ?? pealed the rubbers back & yeah.... all crusty/rusty looking. ive ordered new front pads and rear wheel cyl's, i think i should be able to get the front left to free up and then put new pads in..




cheers fullas
 
what did you mean by how high the pedal is?


as far as the light goes, the 1st 1-2 pumps feel alright, then the next few go really hard followed by the brake light.


........dose sounds like seized slave cyl's doesn't it
 
Yeah I thought that. I pulled the hose off the booster & it still had what seemed like was a lot of vacuum.
 
If you need to rebuild the frount callipers. Get a set off a HZJ75 landcruiser of hilux after 1989 and before 1997 with the full frount diff housing with the 4 big pistons. You have to cut about 10mm off the backing plates and they bolt on and the hoses fit. They have bigger pads and work better.
 
So....I've put caliper kits in new pads, rear wheel cylinders, bled system.

Still no good, soft pedal, brake light coming one.

Anyone know how to adjust the rear portioning valve ?
 
There is a adjuster mounted to the diff with an arm that goes to the valve, it works on load, so the more load the more presure it applys. As load is applied the suspension will lower and apply more brake presure. IF lifted 50mm you really need to adjust or modify the adjuster up 50mm to be at the OE setting.
 
Just rembered we have brake adjuster extentions for the 75,78,79 series, looks they will suit, the 73,74. I will see if will fit on mine over the week end, I am confident.
RRP AU$22

BU59-001 photo.webp
 
Well I fitted the extention, was an improvment in braking. I only went for a quick test drive around the block at lunch today.
I set the braket 50mm above the previous mark and whent for a drive, was expecting to lock up the back brakes if over adjusted but it actually locked the front, which I had not done before.

I assume when max presure was applied previously there was still fluid passing through bias valve and not applying full presure. Now the rear is set back to aproximately the correct setting, the front now receive full presure. I no expert on brakes if any one has a better theory please share.

Th FJ73 with 37" wheels will be getting the adjuster fitted as well for comparison.

DSC02022 for email.webp
 
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