Help Me Diagnose My Brake Issue - 97 FZJ80 (6 Viewers)

[ColoradoLC]

I've owned my 97 since 2008 and have always done my own brakes. I've never had issues with them I couldn't figure out until now, so I thought I would tap on folks who have been there and done that.

I have Powerstop rotors front and rear with OEM pads rear and 100 series pads up front. The rotors are still good, and both sets of pads have plenty of life left.

I have extended brake lines all around to accommodate my ICON/Slinky lift.

The brakes have been fine until late this spring. I went to drive it after it had sat for about a month and the brakes were barely stopping the truck. I have bled it several times now, in the proper order and there's no air in the lines and the brake feel is very stiff, yet it won't even muster enough stopping force to keep me from rolling down my barely inclined driveway.

I thought, well maybe there is still air in the lines, so I bled it again. I got good braking on a test drive, then went to drive it the next day and it's back to barely braking at all.

I'm not losing fluid anywhere and confirmed this through the reservoir.

I'm considering that it is the front brakes that have the issue as a reverse brake test works better than a front brake test. I'm thinking it is either one of the calipers sticking or maybe the brake master cylinder is going bad. Before doing more work, I want to see if any of you have run into this issue before.

Pic for attention.

 

[CruiserDave]

Stiff pedal with poor braking is probably going to be the brake booster or the valve in the brake booster.

 

[alia176]

i doubt if your caliper pistons are leaking but they're easy enough to do a visual on. The rebuild kit from OEM is easy to work with and it's probably time anyway. I do have to wonder if your master cylinder isn't doing its job.

 

[CruiserDave]

When I recently redid all my brake components,less booster, my front right caliper was seized. The feel was soft sinking pedal and a pull to the opposite side. Tightening the front wheel bearings and replacing all calipers, lines and master cylinder fixed the issue. Braking is now normal with no pulls or unexpected long pedal travel.

 

[ColoradoLC]

Stiff pedal with poor braking is probably going to be the brake booster or the valve in the brake booster.

I had not thought of the brake booster. I'll check that. Thanks for the suggestion.

 

[ColoradoLC]

When I recently redid all my brake components,less booster, my front right caliper was seized. The feel was soft sinking pedal and a pull to the opposite side. Tightening the front wheel bearings and replacing all calipers, lines and master cylinder fixed the issue. Braking is now normal with no pulls or unexpected long pedal travel.

I am hoping not to have to replace everything. I just checked the prices on OEM brake boosters and holy crap, over $600 with some almost $700!

 

[alia176]

I am hoping not to have to replace everything. I just checked the prices on OEM brake boosters and holy crap, over $600 with some almost $700!

folks are buying another quality brand of bb, can't think of the name at the moment.

 

[ColoradoLC]

folks are buying another quality brand of bb, can't think of the name at the moment.

It's not the Aisin or Bosch one, is it? I've been looking for those too.

 

[Fj80oregon]

folks are buying another quality brand of bb, can't think of the name at the moment.

Seiken is what your thinking off. I’m pretty sure Partsouq had them for around $450 not much more than the seiken.

 

[Fj80oregon]

https://partsouq.com/en/search/all?q=4461060792

$469

 

[alia176]

Seiken is what your thinking off. I’m pretty sure Partsouq had them for around $450 not much more than the seiken.

That's it, Seiken

 

[CruiserDave]

City racer has good reviews from some of the 40 series guys.https://www.cityracerllc.com/collections/land-cruiser-80-series/products/brake-booster-for-93-to-97-land-cruiser-fzj80-fj80-lexus-lx450

 

[Malleus]

x2 on the valve. By far the cheapest part to throw at the problem.

 

[MissahPapaJ]

Step # 1 - Start vehicle let it run for a min turn vehicle off step on brake pedal several times till pedal is hard to push ( this means you’ve exhausted all the stored vacuum in the booster ) step # 2 - with foot on hard brake pedal start vehicle if pedal drops that means the booster is functioning. Step #3 turn off vehicle and restart let it run for a min turn vehicle off. Go under hood and remove the check valve, it should have stored vacuum in booster. Step # 4 - remove check valve from vacuum line and put your lips to it and suck and blow into it, it should hold pressure one way and let air through the other way during the suck and blow test if there’s no hold on the check valve, it is bad.

 

[BILT4ME]

Also @arcteryx sells the Seiken he's in TX.

 

[CruiserDave]

I believe Seiken is discontinuing the 80 series booster. If so anyone who wants one better purchase them soon.

 

[arcteryx]

Yes, sadly Seiken’s are NLA/Discontinued. I have some that I will keep for personal use and some that I stocked up on and I will sell from time to time. I do have a good used OEM one currently on the site.

Outside of that, your options are like Cardone or OEM.

Let it be another reason that if you need something, don’t procrastinate as it may not be available.

 

[TheRareElement]

Appologies for highjacking this post.......
Just a quick questiion guys,
Are the piston seals on the front the same as for the rear ?

Just came across my mind after breakfast to check the rear brake pads for wear, why not I said, max a 30 min morning warm up and boy was I wrong, I ended taking the brake cylinder out and doing an unitentional rebuild.

The driver side was a mess, piston was stuck, seal shot & leaking, bleed nipple clogged due to grime & some minor rust.
Didn't have a rear brake repair kit so i used one piston seal from a front brake kit I had, seemed a bit larger in diameter But I ended seating it properly (I hope), after greasing it really well and giving it a slight tap using a brass rod that fit inside the piston, seating the piston boot was a bitch......... had no choice as I need the truck road ready.

Did I do the right thing ? Or I eventually need to replace the piston seal with a rear one & not the front ?
Thanks & have a good day....