Yet another LSPV/ABS delete how to... (1 Viewer)

[kenavt]

Would you feel a stiff brake when the engine is off (system depressurized) even if you had air in your ABS module?

My problem is that my brakes are stiff with engine off, but are spongey when engine is on. Wondering if I haven't bled them thoroughly enough. I know that it's not the master cylinder because I plugged those ports and the pedal was stiff with engine on.

 

[alia176]

Would you feel a stiff brake when the engine is off (system depressurized) even if you had air in your ABS module?

My problem is that my brakes are stiff with engine off, but are spongey when engine is on. Wondering if I haven't bled them thoroughly enough. I know that it's not the master cylinder because I plugged those ports and the pedal was stiff with engine on.

I bet if you did a search you might find some potential answers to this issue because I know I have heard about it before.

 

[rhc404]

Would you feel a stiff brake when the engine is off (system depressurized) even if you had air in your ABS module?

Probably so if not much air is trapped. It should be more difficult to detect air in the brakes with the engine off since there's less fluid pressure compressing the trapped air. Try bleeding with a helper if you're using a pressure bleeder. If you can't get a firm pedal with a 2 man bleed there might be air/corrosion in the ABS module.

 

[alia176]

Probably so if not much air is trapped. It should be more difficult to detect air in the brakes with the engine off since there's less fluid pressure compressing the trapped air. Try bleeding with a helper if you're using a pressure bleeder. If you can't get a firm pedal with a 2 man bleed there might be air/corrosion in the ABS module.

too bad Techstream can't be used to activate the ABS solenoids like you can on newer cars.

 

[rhc404]

too bad Techstream can't be used to activate the ABS solenoids like you can on newer cars.

I think there's a way to activate it with some wire jumps. You can also DIY by finding a safe low traction surface to slam on the brakes a dozen times or so.

Makes me wonder how much fluid is retained in the ABS system. It could be 20-30 year old fluid in some trucks.

 

[alia176]

LSPV and ABS out and gone.

I tried to keep the rear 90° elbow bracket intact but, It just wasn't worth the effort of having to monkey with the two lines. I think my solution is nice and easy while being very clean. This part of the hard pipes are well anchored so I don't think we would have to worry about vibration or anything.

A tip for removing the two horizontal bolts on LSPV that is right next to the fuel tank flange. This extra long box end wrench really helped loosening those two bolts. It's a slow and tedious process, but it's very doable with a long wrench.

Another tip that might be useful, since we have all these extra hard piping left over. I'm going to cut the ends of all of them, smash the last couple of inches on a vice then using a needle nose plier, turn them into circles. For emergency brake pipe repair out on the bush, you can use these to stop the fluid from coming out while you limp yourself out of the situation. You can hand out the extra ones to your buddies for field repairs!

 

[77mustard40]

Big brake weekend for me, deleted ABS and LSPV, replaced the booster that laid an egg a couple weeks ago, replaced the caliper soft lines and new pads on all for corners. Replacing the booster was a home run with the ABS out, I could see that being a PITA under normal conditions.

I ended up using one of the coiled lines that come out for the front connection to the MC. Experienced something weird when bleeding, could not get fluid from the PS rear caliper. At first I thought I’d screwed up my ABS delete but then found I had fluid at the DS rear. I ended up partially unscrewing the problem bleeder and was able to get fluid but probably not an effective bleed. Pedal is about the same as it was but the brakes are way better. I’ll get a replacement bleeder today and bleed again tonight.

Gotta love the Motive bleeder and BA-10 small Toyota bleed cap.

 

[rhc404]

Gotta love the Motive bleeder and BA-10 small Toyota bleed cap.

Pedal feel will probably improve with a 2 man bleed. I bled mine clear with a Motive after ABS/LSPV delete and then followed up with a 2 man bleed and it got a little more air and discolored fluid out of the system. The pressure bleeders can't get everything.

 

[77mustard40]

Pedal feel will probably improve with a 2 man bleed. I bled mine clear with a Motive after ABS/LSPV delete and then followed up with a 2 man bleed and it got a little more air and discolored fluid out of the system. The pressure bleeders can't get everything.

I bled the system again solo and tapped the calipers with a small tack hammer while the bleeder screw was open, this helped dislodge some small bubbles from the calipers. I ended up ordering a replacement bleeder screw 47547-12030, after trying a Dorman speed bleeder replacement from NAPA for my clogged bleeder screw, but the darn thing leaked with 12 PSI on the system. I'll get to bleed the rear PS again this weekend when I get the replacement bleeder in. Pedal is getting better though, definitely a big improvement in my binders without ABS & LSPV.

 

[alia176]

one of my nipples was clogged and it was easy to remove it completely then clean it out with a paperclip and blow it through with air. I bet others will have this issue due to the age of our rigs.

 

[77mustard40]

One thing I meant to mention from my ABS/LSPV delete was a finding that seems to support the theory of air being trapped in these ABS units. Here is the elbow fitting on the DS fender well that gets moved back to connect the lines at the LSPV, notice how the fitting facing the ABS was dry when I separated it (last pic)

 

[francese]

Hello I removed the ABS system but I would like to keep LSPV how to connect the hose which is used to distribute the front brakes in photo under the mastervac thank you in advance

 

[francese]

Hello I removed the ABS system but I would like to keep LSPV how to connect the hose which is used to distribute the front brakes in photo under the mastervac thank you in advanceView attachment 3512103

what do you think of this montage?

 

[AcroSteve]

Im deleting the abs, but keeping lspv.
From the pics it appears that other have been using the rear outlet on the master cyl for the front brakes. Is that correct? Is there a difference in volume between the two sections of the master cyl?

Is there a simpler diagram?

Is the line/bracket at the rear of the left front the return from the lspv, or the supply for the rear? It connects to the tee under the master cyl, which connects to the rear section of the master cyl, and the abs pump. I was just planning on blocking the one going to the abs.

 

[francese]

 Hello
for me it's the return pf lspv
I looked at my hzj79 without abs and I do the same on my 80.
apparently there is a difference between master cylinder with abs the output of the front and rear brakes would be reversed...

 

[93yotasr5]

Would that make a difference if you deleted your abs and LSPV, or replaced your abs master cylinder with one for w/o abs?

 

[AcroSteve]

Here's how I connected mine while retaining the lspv

 

[93yotasr5]

Did the full delete, installed a new MC, new booster, replaced frame to axle brake lines with braided lines from @sleeoffroad, used the “L” fitting from the LSPV for the rear and mounted it with the spacer from @Outsane (solve function). I purchased an Aisin (Advic) MC for non-abs and had to bend the line a bit more since the “F” line is horizontal instead of vertical in my old MC. I used some old brake lines to bench bleed the MC.


Got it all bled and then the battery was dead.
After waiting for the battery to charge, I took it for a drive. Immediately I could tell the difference! The brake pedal is a lot more responsive. Well worth all the work ! I second what @alia176 suggested by using a long 12mm wrench to remove the proportioning valve bracket.

 

[Dubbinchris]

Did the full delete, installed a new MC, new booster, replaced frame to axle brake lines with braided lines from @sleeoffroad, used the “L” fitting from the LSPV for the rear and mounted it with the spacer from @Outsane (solve function). I purchased an Aisin (Advic) MC for non-abs and had to bend the line a bit more since the “F” line is horizontal instead of vertical in my old MC. I used some old brake lines to bench bleed the MC.


Got it all bled and then the battery was dead.
After waiting for the battery to charge, I took it for a drive. Immediately I could tell the difference! The brake pedal is a lot more responsive. Well worth all the work ! I second what @alia176 suggested by using a long 12mm wrench to remove the proportioning valve bracket.

View attachment 3525185

View attachment 3525186

View attachment 3525187

View attachment 3525188

View attachment 3525189

Nice work. You have a part number on that non-ABS MC?

 

[93yotasr5]

Nice work. You have a part number on that non-ABS MC?

Thanks. It was well worth freshening up the brake system!
I used the circled MC part number. Check your door plate to confirm year otherwise you’ll need the one I put a check next to. FYI Advics is owned by Aisin and they are stamped Aisin.
I also used a new Tee altogether to make things new and it has a hole that I can mount a bracket to the inner fender for rigidity.
Lastly things the long 12mm I used. Well worth it and I see myself using it a lot in the future.