Front vs Rear ports on master cylinder? (1 Viewer)

[jcardona1]

I deleted ABS and LSPV on my truck several years ago. I'm working on a brake system overhaul and I came across something that's making me doubt my brake line routing.

Which port on the MC goes where after ABS delete? I had always assumed the rear/side port near the firewall went to the front brakes based on how it went to the F port on the ABS unit and the top/front port went to the rear brakes because it connected to R on the ABS unit.

But everything I've been reading says Toyota MCs are front port/front brakes and rear port/rear brakes. Is this correct? I feel like I'm losing my mind!

Here's the factory routing with ABS unit. You can see that the top/front port goes to the R. Am I missing something?

 

[richardlillard1]

The one closest to the firewall actuates the front brakes.

Those who have it setup backwards are also the ones who speak of the rears locking up first, because they’ve done it incorrectly.

 

[jcardona1]

The one closest to the firewall actuates the front brakes.

Those who have it setup backwards are also the ones who speak of the rears locking up first, because they’ve done it incorrectly.

Good to know. That's how I have it setup but I started noticing some people had the front port going to the front brakes.

So then is this information incorrect on Marlin's website or is the non-ABS MC configured differently on these trucks?

Big Bore FJ80 Brake Master Cylinder | Marlin Crawler, Inc.

This is a genuine Toyota large bore non-abs FJ80 Land Cruiser Brake Master Cylinder. This can fit many Land Cruisers models with brake line modification and also makes for a great replacement part ...

www.marlincrawler.com

 

[richardlillard1]

Good to know. That's how I have it setup but I started noticing some people had the front port going to the front brakes.

So then is this information incorrect on Marlin's website or is the non-ABS MC configured differently on these trucks?

Big Bore FJ80 Brake Master Cylinder | Marlin Crawler, Inc.

This is a genuine Toyota large bore non-abs FJ80 Land Cruiser Brake Master Cylinder. This can fit many Land Cruisers models with brake line modification and also makes for a great replacement part ...

www.marlincrawler.com

I don’t have a 91 fsm handy (it’s sitting at the shop), so I can’t confirm this, but looking at the Toyota parts diagram for the brake lines of a 91-92, the port closest to the booster would be the primary, since that line goes down to the front.

 

[Grandlooser]

My brakes work like magic after ABS and Load valve delete. I will check mine later to verify.

 

[Broski]

My brakes work like magic after ABS and Load valve delete. I will check mine later to verify.

So do mine, The rear port closest to the fire wall is going to the rear. The ABS/LSVP delete was done by a shop that the owner is a Cruiser Head, has 2 80s daily one of them and has a 40 build and a 80 build of his own going at the same time. I feel he is a very competent and talented mechanic.
But i would still like to know if this is plumed backwards.

 

[Broski]

I don’t have a 91 fsm handy (it’s sitting at the shop), so I can’t confirm this, but looking at the Toyota parts diagram for the brake lines of a 91-92, the port closest to the booster would be the primary, since that line goes down to the front.

View attachment 2601789

I keep looking at this diagram, after number 3 I can't tell witch line go's where

 

[ThreeEyedBandit]

I keep looking at this diagram, after number 3 I can't tell witch line go's where

Front line of #3 goes to the lower line(47317) to #9 then down(47363) and back(47362)
Rear line goes into 47324

 

[Broski]

Front line of #3 goes to the lower line(47317) to #9 then down(47363) and back(47362)
Rear line goes into 47324

So how does 47362 play in, to me it looks like it go's right to 47317.
Not try to be sharky just try to figure it out. Thanks

 

[jcardona1]

Here's the brake line routing for a truck with ABS.

As you'll see from the color coding, the front brakes (pink) are coming from the rear port of the master cylinder. The front port also has a sensing line (green) going to the LSPV at the rear. The rear brakes are coming from the front port of the MC (blue).

 

[ThreeEyedBandit]

So how does 47362 play in, to me it looks like it go's right to 47317.
Not try to be sharky just try to figure it out. Thanks

#9 is a Tee. 47317 in front, 47362 out the back to the LSPV and 47363 to the front brakes.

When you plumb it without the LSPV, 47317 goes to the front brakes(47363) and ditch 47362. Rear brakes get pressure via 47324.

 

[ThreeEyedBandit]

Following jcardona1's colors. Pinkish front, green sensing and blue rear. This is for a early 80 without ABS.

 

[jcardona1]

Following jcardona1's colors. Pinkish front, green sensing and blue rear. This is for a early 80 without ABS.

View attachment 2602015

This is interesting. I tried the same thing for the non-ABS truck and I'm tracing front brakes to front port. Rear brakes to rear port. Here's a close-up. Did I get it wrong?

 

[ThreeEyedBandit]

That is really weird, I just doodled on the picture above. Your paint tracing is correct to my eyes, as is mine. Confusion is great now.

Yours easily has the lines crossing, as the other doesn't.

 

[jcardona1]

That is really weird, I just doodled on the picture above. Your paint tracing is correct to my eyes, as is mine. Confusion is great now.

View attachment 2602044

Yours easily has the lines crossing, as the other doesn't.

Oh you're right. I didn't even notice that. I was using parts diagrams saved on my computer from several years back. On mine the lines cross over and on the one posted by Richard, they do not. Definitely something fishy going on. I wonder if that's why Marlin says front port/front brakes rear port/rear brakes?

I wonder if @cruiseroutfit has any ideas since he's familiar with all the MC differences. Or perhaps @Onur ?

 

[ThreeEyedBandit]

Got it figured

3FE 80 series(lacking RR Disc option and exhaust heat shield on drivers side)

I sourced similar from here

1FZ, NON-ABS

1FZ, ABS

 

[Broski]

Got it figured

3FE 80 series(lacking RR Disc option and exhaust heat shield on drivers side)
View attachment 2602056
I sourced similar from here

1FZ, NON-ABS
View attachment 2602057

1FZ, ABS
View attachment 2602058

Excellent work,
It looks like for some reason they reversed the ports on the ABS version.
The big question, when deleting the ABS which port goes to the front ?

 

[ThreeEyedBandit]

Excellent work,
It looks like for some reason they reversed the ports on the ABS version.
The big question, when deleting the ABS which port goes to the front ?

When I did my ABS delete I kept the same plumbing as the ABS version. Rear port to the front brakes, and front port to the rear brakes.

Also, looks like the ABS and non-ABS 1FZ 80's use different master cylinders. I would safely say that when ditching the ABS keep the plumbing the same. Rear port to front, and front port to rear when using an ABS MC.

 

[Broski]

When I did my ABS delete I kept the same plumbing as the ABS version. Rear port to the front brakes, and front port to the rear brakes.

If the master is the same one would think it does not matter, mine is the opposite rear to rear, front to front. Breaks work great

 

[jcardona1]

So if we delete ABS, should we be installing a non-ABS MC and reversing the front/rear ports?