Yet another LSPV/ABS delete how to... (12 Viewers)

[COYS]

After reading through the thread, I'm def keeping LSPV/ABS.

Here’s what the parts look like - not sure when I’ll get to actually installing it replacing the og bits.

 

[White Stripe]

So, can I simply remove the ABS portion per the instructions on page 1 and leave the LSPV in place (with some adjustment for being lifted)?

I used flat stock steel to elevate the lspv arm at the axle to compensate for my lift. Then used the arm stud for finer adjustments.

 

[Outsane]

In the first post the line to the lvsp is eliminated. So the routing is is different if you want to keep the lvsp.

 

[Azca]

I have seen that too but like the idea of having a constantly adjusting proportioning valve for the same reasons Toyota included it in the first place. If there's a way to adjust it for the lift I agree with @White Stripe I don't see a reason to delete it.

Is there anything different I need to do under the hood when deleting the ABS unit than outlined on page 1 if I want to keep it? I obviously wouldn't need to harvest the elbow to use in place of the LSPV but anything else to consider?

Thanks all

When I was purchasing all the parts for my rig to convert to hydro boost the folks at BAER Brakes told me the people that race car designers are putting the manual proportioning valve in the cab of the vehicle so they can adjust on the fly. Not sure how accurate this is but I can see the value. Gas, tires etc all impac the settings.

 

[Outsane]

@azcaon a race car the balance of front to rear braking is much more crucial with every corner at threshold braking. They also get repeatable clean corners to compare on.

 

[alia176]

I know that some folks in this thread have installed the wilwood proportioning valve, but I think they are leaving it wide open, basically a 50/50 split. Seems like our vehicles seem to handle breaking just fine without installing the valve in the circuit.

Ymmv

 

[1973Guppie]

I know that some folks in this thread have installed the wilwood proportioning valve, but I think they are leaving it wide open, basically a 50/50 split. Seems like our vehicles seem to handle breaking just fine without installing the valve in the circuit.

Ymmv

yes others have run it without a prop valve but I recc always mounting one especially if your rig is like mine on family trips and we carry lots of weight in the rear cargo area. It is a nice feature to be able to adjust the braking power if needed. For all around driving I set mine to 1/2 the way in and it seems to work great.

 

[White Stripe]

Maybe people leave they're mechanical proportioning valve open fully, and don't notice any issue on dry pavement or don't pay a lot of attention, just my thoughts. But how does it stop on snow, ice, gravel, slick mud etc? Even on a strictly offroad rig it should matter, although im not saying your going to crash into a school bus. But to me that's how you know if the brake bias is correct-how does it stop on those surfaces? For example say your on a trail that's a bit off camber with a slick surface. You apply the brakes slightly, and the rears lock up but the fronts don't. Since the rear is locked up, the rear is going to want to slide off the trail. Going down a steep descent though having the rear lock up early can help with weight transfer. In fact one way to make a very steep ledged decent offroad such as white knuckle hill in moab, is to open the center diff and leave the parking brake on. Making the descent doing a type of front dig maneuver. Which is probably what I would do rather than have the proportioning valve left full open. This is all my personal opinion I'm just throwing out there. I could be wrong.

 

[alia176]

Maybe people leave they're mechanical proportioning valve open fully, and don't notice any issue on dry pavement or don't pay a lot of attention, just my thoughts. But how does it stop on snow, ice, gravel, slick mud etc? Even on a strictly offroad rig it should matter, although im not saying your going to crash into a school bus. But to me that's how you know if the brake bias is correct-how does it stop on those surfaces? For example say your on a trail that's a bit off camber with a slick surface. You apply the brakes slightly, and the rears lock up but the fronts don't. Since the rear is locked up, the rear is going to want to slide off the trail. Going down a steep descent though having the rear lock up early can help with weight transfer. In fact one way to make a very steep ledged decent offroad such as white knuckle hill in moab, is to open the center diff and leave the parking brake on. Making the descent doing a type of front dig maneuver. Which is probably what I would do rather than have the proportioning valve left full open. This is all my personal opinion I'm just throwing out there. I could be wrong here in some ways.

These are excellent points, well made. When I do this project, I'll start with no prop valve in the mix and see how my 80 reacts in certain situations. Given that there is 500# more weight over the rear axle than the front, I have a feeling that I might have a decent functioning braking system. We'll see what the reality ends up being! Mine is a trail rig and the cargo weight changes about 50#, which is basically whether or not I'm bringing the dog

 

[Dave 2000]

Most of those who know me understand I am not happy about removing the ABS or the load valve.

This just to make a few points and not about how someone messing with their brakes caused an accident and/or killed someone, that's up to them and their conscience.

Let's lay out a few scenarios, remember this is not a quick reaction to an up and coming situation where you brake hard and KNOW you are going to stop if you think and handle the situation quickly enough. Then there is the 'moment of inattention' kind of off emergency where either you or someone else was not paying attention and the true FACT that you are almost certainly going to have a crash, and I mean the FACT. That is your thinking time, the speed you are doing, the road surface and other factors means you are pretty much going to have a collision. Feel free to offer your comments, but don't bother with 'I am the best driver in the world and will never crash' or 'I always pay attention so will never be put in an emergency situation', if that's how you think then you should not even own a car let alone drive it and perhaps you should stop stop reading the following as well? Nor being a hard arse but I have been under a car for 50+ years and have heard and read so much absolute bo**ocks from putting on a pancake air filter on the carburetor because it makes the car faster......oh and it makes a great sound, the first reason is bull****, and the second is subjective, to my car goes faster as I use a laptop to tune my car whilst in the middle of a street race, or perhaps watching 'The Fast and the Furious' at the same time.

The following assumes your brakes/tyres are all good with tread/pressure and so forth, and the load valve has been adjusted with pressure gauges attached, I don't ever recall someone saying 'after doing my suspension lift I had the load valve adjusted with the correct equipment' or even after fitting a new load valve saying the same thing.


Scenario 1, You are driving you 80 with just a single passenger, you are driving on a dry surface with good traction and an emergency braking situation is called for, but I mean a REAL braking situation, you will NOT, evaluate the surface condition, you will NOT try to gauge your stopping distance, what you WILL do is slam on the brake pedal as hard as you can, it could be someone pulling out in front of you, a kiddy running out in the road or perhaps even a dog, the very fact that you suddenly see something that is pretty much unavoidable you will react by braking as hard as you can, again the suddenness of the situation you may not have a chance to steer away but this is also another normal reaction.


So what does your 80 do in reaction to your panic braking?

The front and rear brakes come on, both the front and rears make the attempt to lock and the ABS comes in to prevent this, the front brakes having the weight of the engine over them increases the traction and more stopping power pulling the front of the car down, hence front brakes are designed to take advantage of this by being larger in size. At the rear of the car two things will be happening with the brakes, the relative light weight of the rear of the car versus the front means the rear wheels will attempt to lock, to prevent this the ABS will be activated but in conjunction with the load valve. That is the ABS is fluctuating the brake pressure to the rear brakes, and the load valve will be reducing the pressure but only for the period of time until the vehicle comes to a stop, that is the vehicle has returned to it's pre accident level.

Scenario 2, So what happens if the road is wet/greasy or even icy? Everything is pretty much the same as scenario 1, same passenger, same weight and same emergency condition except, the load valve will NOT reduce the pressure to the same degree. The front traction being reduce by the poor surface means that the front does not dip and of course the rear does not lift so the load valve barely moves if at all so the reduction in pressure is not so pronounced as in scenario 1, you are pretty much relying on the ABS to stop the rear wheels locking.

Scenario 3, This time the the vehicle is fully loaded, passengers with luggage and so forth, so now what happens? Exactly the same as in scenario 1, and 2, this is why the ABS is so important, it's function is null but not like the ABS which responds to all conditions (which is more important), because as we know the load valve will vary the pressure to the rear brakes depending on load but is unable to do this on an icy road, as again there is very little movement of the valve due to lack of change in the vehicles attitude.

I would point out that no ABS on any vehicle on a loose surface will bring it to a stop quicker, a pair of locked wheels off road would see tyres dig into the loose surface, this builds up a 'wedge' of soil/gravel in front of the wheel helping to stop the vehicle.

I would say if the 80 brakes had a design issue it is the size of the brake disc/caliper combination which I would say this can lead to early overheating when off road in mountainous areas. This would be worse in an automatic due to the lack of engine braking of an automatic behind a petrol engine. add in the bigger wheel/tyre and suspension lift combination. This is not an issue of just driving around town keeping in mind the all up train weight of an 80 with a trailer is around 7 tons, so the brakes are adequate. I have yet to see someone off roading fully loaded and towing a 4 ton trailer, but assuming no trailer but full of camping gear etc, I know the fitting of the bigger wheels forces the driver to press the brake pedal harder for the same amount of retardation than when the smaller wheel/tyre combo was fitted, this creates more heat, and then the suspension lift without resetting the load valve (with gauges) moving the load valve into a position of less pressure to the rear wheels means the rear brakes are contributing less to the overall braking effort, this again forcing the driver to press even harder on the brake pedal to bring the vehicle to a stop adding even more heat to the front brakes, so this incidentally may explain why the wear rate of the 80 front brake pads is excessive due to the excessive work they have to do.

These are thoughts and opinions drawn from my own experiences with off road competitions (competitions in a Land Rover and never in an 80) my experiences off road in my fully loaded (3 tons) 80 and of course added to my aforementioned years as a mechanic and still running my own business (presently closed due to a long term health issue), if I was to ever make modifications to the braking system other than the dimpled (never fit cross drilled discs) and slotted brake discs I fitted all round to my own 80 a few years back, I would fit larger front brake discs/pads/calipers and a matching master cylinder, this along with a correctly set load valve then I think this would be a better option than removing the ABS and load valve, I see no benefits in doing this whatsoever, recounting what I have said, if you have poor brakes without bigger wheels/tyres or suspension lift then a fault exists.....period.

Regards

Dave

 

[bhsdriller]

tldr
cool story bro

 

[Outsane]

Came back from a snow wheeling trip, I really enjoyed not having the abs kick in while going slow over ice and snow especially down hill.

I also played with slamming on the brakes to see if the rears lock up and I wanted to put in an adjustable prop valve. So far I am good.

Oh and my buddies front caliper locked up on the freeway... newer vehicle.

 

[alia176]

I also played with slamming on the brakes to see if the rears lock up and I wanted to put in an adjustable prop valve. So far I am good.

So, what did your test reveal? Were you able to lock up the rears before the fronts? Is that why you're going to be installing a prop valve? Or, did I interpret your statement completely wrong?

 

[TYM4FUN]

So, what did your test reveal? Were you able to lock up the rears before the fronts? Is that why you're going to be installing a prop valve? Or, did I interpret your statement completely wrong?

Yeah, you fawked that all up.

 

[Outsane]

@alia176 so far no need for a prop valve for me. Maybe that because I have a lot of weight in the back. Might be different for a stock rig

 

[alia176]

@alia176 so far no need for a prop valve for me. Maybe that because I have a lot of weight in the back. Might be different for a stock rig

Your feedback is the norm for "loaded" rigs, folks who installed them leave them in the wide open position. Other folks do the "wait and see if need a prop valve" and end up not needing them at all.

As for me personally, locking up ANY tires on dry pavement was never an option for me. Given that my 80 is always heavy in the rear, the LSPV isn't doing a whole bunch either, except for maybe during emergency brake stomping situations.

When the weather warms up, i'll start tearing out and reconfiguring stuff.

 

[Outsane]

Sounds good

 

[Highlex]

Sorry to revive this thread, i've read the whole thread and can't find 1 answer to a simple question.

If I just plan to remove the ABS pump and keep the LSPV, do I need to purchase a brake T fitting to complete this job, or is the brake T fitting I need already there and unused after I remove the ABS pump?

Thanks!

 

[baldilocks]

Sorry to revive this thread, i've read the whole thread and can't find 1 answer to a simple question.

If I just plan to remove the ABS pump and keep the LSPV, do I need to purchase a brake T fitting to complete this job, or is the brake T fitting I need already there and unused after I remove the ABS pump?

Thanks!

No parts should need to be purchased.

 

[MUDZLLA]

Since this thread has been revised anyway... how do you delete the LSPV on an 80 without ABS?