Need some technical help i.e. I'm stuck (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Last night I convinced my wife to go out and help me after the kids went to bed. We tried the pressure bleeder and pumping the brakes per this thread:


I was surprised that more bubbles came out. The brake pedal felt stiffer, but when I turned on the car you could still get it to touch the floor. I doesn't feel like it is sinking, it feels like it is traveling and then run out of room. It also feels like if I had another inch of travel it would stop.

I'm running out of ideas and I need to take it to someone to fix it for me.
Do you think the booster might be shot?
What happens when you pump brakes?
Does it hold?
 
Do you think the booster might be shot?
What happens when you pump brakes?
Does it hold?

I have replaced the booster a while ago with a remanufactured one.

I put plugs on the master and when I did that it held pressure great. I think that would mean both the master and booster are good. a leak in either would cause it to fall in that set up.
 
I have replaced the booster a while ago with a remanufactured one.

I put plugs on the master and when I did that it held pressure great. I think that would mean both the master and booster are good. a leak in either would cause it to fall in that set up.
What happens when you pump the brakes?
Does it hold pressure?
 
What happens when you pump the brakes?
Does it hold pressure?
I'm not sure how to describe it. It takes X amount of force to press it down and it will go to the floor, I pump it several times, and it still takes x amount of force to press it to the floor.

With the engine off it doesn't feel like it pumps, it feels like it doesn't pump up, it just goes to the same spot each time.

The x amount of pressure it take to go to the floor is a moderate amount. it doesn't go down easy.
 
I am starting to think it is the brake booster. When the vacuum is off, the pedal feels solid. When I attach it, is when it feels mush. I drove it today and it has plenty of stopping power.

Last June I bought this boost: 1993 - 1997 Toyota Land Cruiser | FZJ80 | FJ80 *New* Vacuum Brake Booster (Part Number 4461060792) - Wholesale Parts Express - https://www.wholesalepartsexpress.com/product/93-94-95-93-97-toyota-land-cruiser-fzj80-fj80-new-vacuum-brake-booster-part-number-4461060792/ It's made by Mototeknika, which is probably quality. I should probably swap it out for a Seiken 80 Series, NEW OEM Seiken Brake Booster and OEM Gaskets (2), 44610-60792 - http://www.cruiseryard.com/80-series-new-oem-seiken-brake-booster-and-oem-gasket/

I still have my original vacuum booster. I took it off because it lost boosting and the engine was suffering from an obvious vacuum leak. I am trying to remember if I swapped my vacuum line before or at the same time. I think I did swap the line out before the vacuum booster failed. So I think my old one is bad.

Is there a way to test the booster?
 
I am starting to think it is the brake booster. When the vacuum is off, the pedal feels solid. When I attach it, is when it feels mush. I drove it today and it has plenty of stopping power.

Last June I bought this boost: 1993 - 1997 Toyota Land Cruiser | FZJ80 | FJ80 *New* Vacuum Brake Booster (Part Number 4461060792) - Wholesale Parts Express - https://www.wholesalepartsexpress.com/product/93-94-95-93-97-toyota-land-cruiser-fzj80-fj80-new-vacuum-brake-booster-part-number-4461060792/ It's made by Mototeknika, which is probably quality. I should probably swap it out for a Seiken 80 Series, NEW OEM Seiken Brake Booster and OEM Gaskets (2), 44610-60792 - http://www.cruiseryard.com/80-series-new-oem-seiken-brake-booster-and-oem-gasket/

I still have my original vacuum booster. I took it off because it lost boosting and the engine was suffering from an obvious vacuum leak. I am trying to remember if I swapped my vacuum line before or at the same time. I think I did swap the line out before the vacuum booster failed. So I think my old one is bad.

Is there a way to test the booster?

If you decide to go with a new booster this one works and is less $$ Brake Booster for '93 to '97 Land Cruiser FZJ80 FJ80 Lexus LX450 - https://www.cityracerllc.com/collections/land-cruiser-80-series/products/brake-booster-for-93-to-97-land-cruiser-fzj80-fj80-lexus-lx450
 
Oh that looks attractive. I'm not one for parts snobbery. I just need it to work. They have a great installation guide.

Edit: I have been reading this thread ( New Seiken 44610-60792 brake booster? - https://forum.ih8mud.com/threads/new-seiken-44610-60792-brake-booster.1213795/ ) and it looks like this is a part that needs to be picky about.

Edit 2: Speaking of picky parts. Right now I have a standard vacuum hose, same ID as the original hose. Is it important to get the OEM hose? I am not sure how, given the same length and diameter it should function the same.

80 Series 1FZ Brake Vacuum kit - https://absolute-wits-end.com/80-series-1fz-brake-vacuum-kit/
 
Last edited:
I think I have it now. I took it to Brakes Plus and Keith let me use his bleeder there. I didn't see any bubbles come out. So I adjusted the pedal up some, by moving the fork out to the end of the push rod coming out of the firewall. Then I adjusted out the plunger going from the brake booster to the master cylinder.

Now when you give it your all the pedal stops just before the floor. It feels "soft" but it stops well. And it can really get it to stop when I stomp on it. It just doesn't feel "tight." I think I am going to live with it the way it is for now.
 
I think I have it now. I took it to Brakes Plus and Keith let me use his bleeder there. I didn't see any bubbles come out. So I adjusted the pedal up some, by moving the fork out to the end of the push rod coming out of the firewall. Then I adjusted out the plunger going from the brake booster to the master cylinder.

Now when you give it your all the pedal stops just before the floor. It feels "soft" but it stops well. And it can really get it to stop when I stomp on it. It just doesn't feel "tight." I think I am going to live with it the way it is for now.
Bring it to the next meeting and and see how the other 80s are stopping; maybe someone will let you test drive their rig. I would say that you still have something off.
 
For those of you keeping score, my bad brakes are winning by 100000000000 points to 2.

In the last 24 hours I took it out for a drive to see how it was doing.

Drive 1: The pedal felt super tight, just touching the pedal caused the LC to stop. It was obviously dragging. The front wheels were hot, there was a strong brake smell.

Drive 2: about an hour later I drove it again, this time down 72 for about 10 minutes. The pedal felt normal. The wheels were cool to the touch, no smell of brakes. Stopped fine. Looked like it was working great. I was so happy.

Drive 3: The next day I went to put gas in it. The pedal felt super tight, just touching the pedal caused the LC to stop. There was pulsation in the brakes. When I turned right there was a vibration. When I got to the gas station there was smoke coming from the front RIGHT brake. The wheel was surprisingly cool to the touch. I drove it home, on a flat road I took my foot off the pedals, and it slowed to a stop. When I got it home, there was smoke coming off the front LEFT, this time.

Drive 4: About 20 minutes after getting home I decided to drive it around the block one more time. This time the pedal felt normal. It drove normal. No pulsation, no vibration. Stopped fine, coasted fine.

The only thing I can think of is that the vacuum boost is engaging weird causing the dragging. Then the next time the vacuum boost is operating normal. So I went ahead and ordered a new Seiken booster from cruiseryard. I hope this does it. I hope by buying a "name brand" part instead of a discount part that I eliminate a variable.

I just want to be able to drive my land cruiser again. 😭
 
Update. I have installed the new booster and master cylinder, bleed it using the pressure bleeder... Had to do that twice because I emptied the master cylinder reservoir once and sucked air 🙄

Drove it around yesterday, felt awesome. Stopped quickly and did not give any signs of dragging!

I am going to drive it around a little more before I say I got it. 🤞
 
Update. I have installed the new booster and master cylinder, bleed it using the pressure bleeder... Had to do that twice because I emptied the master cylinder reservoir once and sucked air 🙄

Drove it around yesterday, felt awesome. Stopped quickly and did not give any signs of dragging!

I am going to drive it around a little more before I say I got it. 🤞
That's good news! :beer:
 
When I first got mine my brakes were horrible. Read on the forum for like a week trying to figure it out. Bled all the lines still spongy. No signs of any leaks. Until I squeeze the boot on the rear portioning valve. I read a article on how to eliminate the portioning valve and abs. Definitely the cheapest way to go. Then a year later the booster failed. Got one from cruiser yard out of Texas. They were the best price for a factory replacement.
 
When I first got mine my brakes were horrible. Read on the forum for like a week trying to figure it out. Bled all the lines still spongy. No signs of any leaks. Until I squeeze the boot on the rear portioning valve. I read a article on how to eliminate the portioning valve and abs. Definitely the cheapest way to go. Then a year later the booster failed. Got one from cruiser yard out of Texas. They were the best price for a factory replacement.
Yeah that's true. That's where I got my booster from.
 
If air ever gotten in the ABS system that's a big problem. From what I understand you have to use the ABS system. Basically hammer down on the brakes and a field or something. To get the air to migrate out.
 
The booster was a hard one to diagnose. It wasn't quiet as any of the articles described. May have been just a pin hole in the internal diaphragm.
 
The booster was a hard one to diagnose. It wasn't quiet as any of the articles described. May have been just a pin hole in the internal diaphragm.
I agree.

I am just glad I was able to get it out of the barn in time for the next project.

PXL_20210305_002332170.NIGHT.jpg


PXL_20210305_002322384.NIGHT.jpg


PXL_20210305_001945875.jpg


IMG_20210304_183324.jpg


I have to tell my dad that "driving the wheels off of it" is supposed to be an idiom.
 
I have been looking at trailer parts for my car hauler. That e-trailer.com. but I was driving down 565 a few weeks back. Looked over and saw redneck trailer supplies. Didn't stop in but with a name like that might be interesting.
 
I have been looking at trailer parts for my car hauler. That e-trailer.com. but I was driving down 565 a few weeks back. Looked over and saw redneck trailer supplies. Didn't stop in but with a name like that might be interesting.
We ended up buying a new axle from a manufacturer in Snead. We got it for a song and a dance. We were out of pocket just over $200. Springs, hubs, everything.
 
any vehicle with reasonable time on it....I would swap out all the rubber brake hoses...regardless of how things look on the outside, noteablly where brake issues otherwise can't be resolved.
 

Users who are viewing this thread

Back
Top Bottom