"NE'02 TACO Rust Restoration"

In this non-ABS diagram, I traced what I assume is the flow path of the lines. Supply in green, return in red. Starting from the master cyl, it flows into the driver side port of the first t-junction, and out through the center and passenger side ports of the t-Junction. From the passenger side port of the T-junction, it goes to the front passenger brake. From the center port of the T-junction, it flows into the top port of the forward (higher) T-block. From there it goes out the front and rear ports of the forward T-block. The front port of the forward t-block feeds the front driver side brake. The rear port of the forward T-block flows to the long line to the rear and into the P-valve. From the P-Valve, it returns (marked in red) up the other long line to the rearward (lower) block (which looks the same in both ABS and non-ABS models). From the lower block, it returns to the master cylinder. **BREAK** Looking at the P-valve, it flows into a t-junction which splits off to the rear passenger and driver side brakes.


If I'm correct, it looks like we may need to replace those two blocks connected to the long lines with non-ABS blocks. That would minimize the amount of new lines needing to be made. In the ABS diagram, the center port of the first T-junction off the master cyl feeds the driver side front brake alone through that elbow in front of the two blocks in your picture.

After writing all this I realized you never mentioned you're doing an ABS delete, just replacing broken lines? I'm planning to delete the ABS in mine, so this is what I might do. Don't mean to spam your thread.

Let me know if you see any errors in my analysis.

 

Thank you for finding the schematic. And yes, there are differences as you spoke of. I have the non ABS type and still the front or forward junction block sits higher than the rearward junction block. Your routing thoughts are correct in my opinion. I see no errors in your analysis.

 

That's strange. The non-ABS diagram shows that front block is a 3-way junction, not a 2-way like in your picture. The ABS diagram shows it as a 2-way. Both versions have the same part number in the parts catalog though.

 

That's not my picture, that is a stock footage photo that I found through an on line search, I realized it was different because it was missing the third port on the forward block, I was just using it for an example..

 

Oooooohhhhh

 

Sorry for the confusion, but it's still a good thing that this issue is being sorted out, hopefully it will help other folks to understand how these BPV's work with regards towards line routing.

 

Yeah hopefully. Well, according to that diagram, it looks like the supply line feeds the lower of the two inline ports on the PV and the upper port connects to the return line. I could only find one diagram of the PV, but it doesn't indicate where the lines connect. That PV is identical to the OEM one in design. I assume that part of the lines will be identical on both ABS and non-ABS models. I'll try and snap a pic of mine when I get off work.

 

You have it dialed in, good info, a good addition to the knowledge base.

 

By typing "BPV" in this forums search results it shows a couple of other references that speak to the issue.

 

So I did that and now I understand how the OEM LSPV works. Did you say you're relocating yours to the front? If you do, won't you lose the load-sensing functionality from it? Or will you be able to manually adjust it?

Since I have no reason to believe my LSPV is bad. I may end up keeping it and not messing with the rear brake lines at all, as long as I find them to be intact and solid. That way I'll only have to mess with the front lines when I remove the ABS.

 

I'm not going use adjustment, I'm going test it at the no added weight setting, what I believe is 70% front bias and 30% rear bias.

 

This thread is interesting, the costs discussed are insane.

Load sensing brake proportioning valve?
Discussion in '1st Gen. Tacomas (1995-2004)' started by CdnSldr, Feb 2, 2011.


https://www.tacomaworld.com/threads...ly adjust the braking pressure at that moment.

 

Prices haven't gone down from those ancient times. Good thing you can get a simple replacement from Amazon for a fraction of OEM cost. I need to get familiar with the kind of connecting hardware involved in these lines. My project will require 3 custom lines in the front with one additional 3 way tee to configure it like a pre-ABS model.

 

Found this helpful https://www.roundforge.com/articles/toyota-brake-maintenance-tips/#Toyota_Brake_Flare_Type_

 

I tried the flaring tool with the tee handle, I bent the handle. I then bought the flaring tool with the hex head, now I use an impact wrench and impact socket to squeeze the flares, much better in my opinion. Clamp the tubing vise that is part of the tool in a larger vise and use an impact, start with low pressure and work your way up, experiment without fittings in place until you find the right combination for your application, a good looking, smooth flare without any cracks or splits, then you can start building lines with fittings in place.

Note: Read that as a smooth double flare without any cracks or splits.


https://www.ebay.com/itm/333633113305

Also, with brake tube annealing, heating and slow cooling sometimes helps with flaring process.

Softening
Softening is done to reduce strength or hardness, remove residual stresses, improve toughnesss, restore ductility, refine grain size or change the electromagnetic properties of the steel. Restoring ductility or removing residual stresses is a necessary operation when a large amount of cold working is to be performed, such as in a cold-rolling operation or wiredrawing. Annealing — full Process, spheroidizing, normalizing and tempering — austempering, martempering are the principal ways by which steel is softened.


Annealing is a technique used to recover cold work and relax stresses within a metal. Annealing typically results in a soft, ductile metal. When an annealed part is allowed to cool in the furnace, it is called a full anneal heat treatment. When an annealed part is removed from the furnace and allowed to cool in air, it is called a normalizing heat treatment. A stress relief annealing is when only the first stage of annealing is performed. The second stage of annealing is recrystallization, where new stress-free grains grow. The third stage is grain growth, which causes the existing grains to grow.

https://www.metallurgyfordummies.com/heat-treatment-of-steel.html

 

How's your build coming along?

 

I putter with it almost every day, it's getting better, I have pics but lack a way to download them from my flip phone, I'll update this thread soon.

 

My project is advancing, getting close to firing up, a couple weeks away from driving it. Lotta welding to be done.

 

Where are you at with it? Got the frame done yet?

 

The frame work is around 80% complete, the fab is spot welded, it needs to be welded off and the ambient temperatures are slowing that process, I get an hour or two in the morning where I can weld comfortably and the rest of the day is a wash, it's simply too hot outdoors to weld. I do what I can in the heat, work on brakes, or wire harness routing, that kinda stuff, detail work as it is. I can usually hack the heat until mid day by staying hydrated and in the shade, but at peak I retreat to the indoors and air conditioning, if it cools some after the sun goes over I go back out and putter some more.