Rear ABS WITH Rear Load Propotioning Valve? Whats the point?

I have a simple question with maybe a not so simple answer. It appears the last year the first gen Tacomas were manufactured (2004). They came equipped with front and rear ABS as standard equipment. Sooo with this information why was Toyota still using the Load Proportioning Valve system in combination with rear ABS? Seem to be over kill, beings both systems are to prevent rear wheel lockup?

 

The valve gives more force to the brakes. Wheel lockup with a load is gonna occur later with a bunch of weight in the bed

 

So the valve (in simpler words) is for controlling the right ratio of clamping to lockup force, while the ABS keeps wheel lock up or skidding in check?

 

The proportioning valve adjusts rear brake pressure in relation to the load. it will not prevent lock up but will allow more brake force with a load than with an empty bed the ABS will not adjust brake force in relation to weight and only comes into play when lock up is sensed.

 

I have yet to have a LSPV that worked

 

My rear brakes don't work period...

Such a stupid system if you ask me. I'm getting rid of all the drum and bullshit to go with it within the next few weeks. Going to do the GM disk conversion

 

I like my drum brakes never had any issues just did them the first time at 195,000

 

Its a pretty interesting design. I dont think I have ever seen it on other trucks (dodge, ford,Chevy). What would be the symptoms of the lpvs not working correctly?

 

You have a 6" lift - correct?? Did Fabtech include a brake proportioning lift bracket with the kit?? I would hope the kit should have included one.

When you lift the rear of the 1st gen trucks....you need to raise the brake proportioning arm the same amount to get it back to 'stock' position at the valve. If you don't have a bracket to raise it 6", then you need one.

Here is a photo of one lifted slightly ...maybe 2". It's as simple as a piece of steal with 4 holes in it.

 

Yes, fabtech did supply me with one and it is in use. However during my rear suspension work, i tried to tweek the height of the arm by loosening the two nuts that sandwich the arm bracket in place. The bottom one loosened up fine, but the top (longer) nut did not budge and i ended up snapping the eyebolt in two. I ordered a used one and is on its way, but for now i have a longer eye bolt in its place



This is just temporary until my new one comes in, but it works great

 

I would put the stock eye-bolt on....and see what happens. Your temporary fix there is TOO MUCH lift on the the arm.

I'm guessing you probably have a lot of 'nose dive' when braking?

 

Actually its exactly where is was prier to the lift. Before i took things apart i measured the space between the arm and the bottom of the bed so i could see if it need to be adjusted after the spring lift. I Measured 13 3/4in before lift and it measures 13 3/4in now. But this is just temporary and the stock one is on its way.

 

This photo is a picture of the stock position. You already have a black bracket that's probably 6" tall - which should do fine for your 6" lift. That's why I mentioned keeping the eyebolt at stock size.

 

Nice,

 

There is no point even without the abs its an overly complicated totally unnecessary system much like the emergency brake system. The simple brakes on my old 71 pickup which I drove for close to thirty years worked way better than the Tacoma brakes whether loaded or not, I like the Tacoma but some of the systems are terribly engineered.

 

Some of us learned to drive Empty pick up trucks before any brake LSPV`s or ABS brakes.

One just drove according to the conditions